The Official N/A Upgrade FAQ

[GotToyota?]

Read the whole thread before making a decision on mods. This first post isn't completely accurate but I decided to leave it in it's original form so you could see the debates and stuff in the thread.
-Ma70.Ent

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I'm mainly doing this to 1) help out people wanting to know how to upgrade their N/A's, and to 2) make it so people do not make the usual "what upgrades should I do to my N/A" threads. Below, I'll state what the reasonable upgrades are, what your routes are, and how you can get these parts. Goes from more simple, to mild, to extreme. Mods can edit this anytime if you'd like to organize/tweak this thread.

Intake
First, you need to get that engine breathing better. Start giving it more oxygen by adding an upgraded intake to it. The most restrictive part of the stock intake system is the airbox, so buy something like the K&N FIPK to replace the airbox. You can also just get a filter/adapter on Ebay for pretty cheap, I bought mine for $20, works nearly the same.

Exhaust
This is somewhat of a controversial subject as far as exhaust systems go for N/A's. One thing you need to realize before upgrading your exhaust is that backpressure on a naturally aspirated engine is your enemy! An increase in backpressure will result in a loss of power, which is what you wanna stay away from. So you people with your 3" exhausts, you've actually lost power. The most reasonable size to use when doing your exhaust is 2.5". You're upgrading to a bigger size thus adding abit more power, and you don't have to worry about backpressure. And as far as sound goes, it's up to you on the muffler you want to use and if you want to use a test pipe/cat. I personally kept the stock cat and added a resonator so the sound was more deep and not very loud, sounds great. You can also look into getting a test pipe, but that is illegal in some states/counties and I will not go into any depth concerning that.

EDIT by Ma70.Ent: Read this thread for more info.

http://www.supramania.com/forums/showthread.php?t=49151

Headers
If you've already added an upgraded exhaust, a header might be advised if you'd like to get the full flow out of your system. OBX and Pacesetter are just some of the companies that make these upgradeable headers, but unfortunately due to what many users have stated, they need to be modified in order to fit. If you are in a situation where you do want to get one, 935 Motorsports (who is a sponsor on here) sells these manifolds already modified to fit, as well as some that are 2.5" all the way out to maximize flow.

Porting/polishing
This is more of a mild mod, but can be the one of the most expensive mods if you go into more and more detail with the shop you choose to work with. Remember when I said flow was the key? It's the same concept here. The stock y-pipe and the intake manifold are pretty restrictive, take the time to hollow everything out (you can polish it if you want bling, and easy to clean areas), to get the best flow possible from your parts.

1-piece driveshaft
Everyone has gotten into the situation at one time or another where their carrier bearing has gone bad. Not only does this affect performance, but the weight of the stock driveshaft is unbearable, at nearly 30+ lbs, you have to give alot of effort at times to get what you want out of your car. Get rid of this problem by going with a 1 piece driveshaft, this will put less stress of your effort to accelerate, making the rotation mass less. You can either choose steel or aluminum, but I recommend steel as it's around 15 lbs, aluminum is around 11 lbs, but I personally think it's too extreme if you're staying N/A. Jawsgear is one company that sells these driveshafts, and they're on the forums as well. You can also go to a local welding shop in your area if you want to save some $.

Lightened flywheel
This of course applies to those with a manual transmission. The idea with these lighter parts is to give you less rotation mass, making driving easier as you give less effort because you've lowered the mass. A lightened flywheel is something that can help out in this. With this application, you will see throttle response, as well as easier shifting/throttle ease. The idea is to get rid of the rotation mass as much as possible.

Smaller/lightened wheels
This upgrade certainly isn't necessary (but then again, none of these are ;)) but it certainly does help. Find some aftermarket/stock wheels that are lighter then the sawblades or whatever wheels you have currently. I'd personally recommend the 3rd gen RX-7 wheels, as they are very light, and a simple 5 spoke design. This upgrade will lighten your car, give you easier braking power, and not give as much trouble when accelerating (will give you better throttle response basically).

Lightened body parts/weight reduction
This is of course for the enthusiast that wants to go "all out" and wants to of course compromise the stock look of the car. Lighten the somewhat heavy Supra by dropping a few pounds. One of the easiest ways to start off is to get ahold of a CF/fiberglass hood. The stock hood is quite heavy, and you'll save more then a dozen pounds by doing so. There are no other lightened body parts that I know of, but you can always make custom fenders/hatches if you really wanted to go all out. As far as interior weight reduction goes, the seats are something that should be replaced with a lighter aftermarket application. Ebay sells some generic Bride replica seats that are very light, and grip you very well, they're around $350 dollars (just an idea of what Ebay offers). You can also take out the backseats, as well as the spare tire board and the spare tire/accessories to go along with it. This is of course another upgrade for the hardcore enthusiast. It is recommend to relocate the battery to the rear if you take out alot of weight from the back.


Raise the compression/build the head, aftermarket pistons
Again, this is advanced modding. Time to go with an aftermarket MHG to raise the compression. Thickness for the MHG depends on how much you need to mill off the head, then you go from there. I'd suggest a 1.2MM HG if you have a normal head/block. If you have alot of warping however, 2MM might be the way to go. Also, buy aftermarket pistons that are slightly bored over, you might as well if you want to raise the compression and get the full benefit of your motor.

Fuel and timing
If you have done enough mods, you will know that there is always more that you want. Well, a simple way to benefit more from your mods is to raise the stock timing. The stock timing according to TSRM spec is around 10 degrees. Raise the timing to 12-14, depending on how extreme you wanna go (but be warned, you must go with higher octane fuel if you raise the timing). If you wanted to go the extra mile, you could also get an SAFC to fully tune and take advantage of your powerband.


Ignition
To key is to get better spark. High output capacitive discharge sparks ensure complete combustion of the fuel mixture especially at high rpm. You don't want your system to fail because of your ignition system. MSD along with a few other companies make ignition systems for decent prices.

Cams
This is a mod for those going the next step. Since you'll be N/A, it's recommended to go with a mild set of cams, too extreme and you won't be running so good unless you have the supporting mods. There is an online website that regrinds your stock cams to around 244 degrees, which is mild enough for an N/A wanting to go the extra mile. http://www.webcamshafts.com/toyota-auto.html

-Matt

[Ma70.Ent]

So you people with your 3" exhausts, you've actually lost power

There are some people with 3'' exhausts who have felt no power loss at any point. So I don't think you should be saying this unless you really confirm it.


You can also take out the backseats, as well as the spare tire board and the spare tire/accessories to go along with it.

This is usually not suggested since you're removing the weight off the back of the car (which is where it is needed to have traction)

Also... Advanced timing to 14-16 BTDC if you run premium 91-93 (which you should always) always helps.

[jmanbball]

Relocate the battery to the rear to help with weight distribution

[Ma70.Ent]

To those who want to know about one of the "craziest" N/As there might possibly be...

Defiant 7M's build (http://www.supramania.com/forums/showthread.php?t=46)

For other N/A mod pages that are somewhat old, but are from a reputable source..
http://www.4cefed.com/naperf.html
http://ma70.com/bishop/namod.html

[Ma70.Ent]

Ignition - while the turbo's ignition system is pretty decent, the n/a's can use some improvement once you've done all the bolt-ons. On the dyno I gained no power with the ignition on or off with my mods. Checking for increase in spark it was VERY noticeably stronger with the HKS unit but there was no extra power to be had. There are many choices here since its pretty much all universal. All of them except the HKS system require a tach adapter and a extra high performance coil.

Hmm.

[Nick M]

3 inch exhaust is too big. You will lose velocity and scavenging. There is a balance point between backpressure and lost velocity. 2.5 is even pushing it. Yes, it is confirmed. The mod that makes it sound better does not make it faster.

Increase compression from chaning pistons, not by taking material off the sealing deck.

And lose some weight.

Nice article. You put some thought and time into it.

[Kai]

There was information on the UK Mk3 forums about the GpA Supra Rally cars of the 1980's and 1990's and there were some pretty hot N/A's racing.

The way they squeezed more HP out of them was increasing the compression to 11.3:1 - although how they did that, i'm not sure. Would i be correct in saying that it was a combination of Higher compression pistons and skimmed head, or could that be accomplished with pistons on their own?

[supramacist]

On my stock air intake. I have taken the air filter housing and have dremeled the front face off of it. Now you can see the k&n inside. All I have to do is get the passenger lamp hood scoop. Or run it down to the nose of the car.

Filters are still 50$ But I still keep the afm. I have been down with a bhg and are about to begin the rebuild. A winter project.

[Nick M]

You can deck the head, have it machined, that is the same thing. That will make the combustion chamber smaller. You can change pistons to one that does not have deep valve reliefs. They will both increase compression.

Increasing the stroke will change the compression with no other changes also.

[Kai]

If you alter the head and/or pistons - is there a limit as to what lift the cams can produce? Also, whats the diameter of the valves as stock, and what lift do the stock cams give?

[89Joe]

This is long overdue! You guys need this! also!


Below is an assortment of threads with "N/a Power" in mind.
Please realize these are in no particular order, and one might be better then the other.

Ideas on what you should upgrade.
http://www.supramania.com/forums/showthread.php?t=16948

N/a Powerr.
http://www.supramania.com/forums/showthread.php?t=30526

This is one by Robert up at 935motorsport.com Great stuff here
http://www.supramania.com/forums/showthread.php?t=15997

"Best mods for our N/a's."
http://www.supramania.com/forums/showthread.php?t=27523

hot titz for intake ideas!
http://www.supramania.com/forums/showthread.php?t=22970

N/a tuning ideas.
http://www.supramania.com/forums/showthread.php?t=24145

Some more stuff on intakes and porting and polishing.
http://www.supramania.com/forums/showthread.php?t=24839

Below are good threads with ideal topics related to your request

This is a good one to get a taste of what one person is doing to gain some power
http://www.supramania.com/forums/showthread.php?t=16000

This was an intense thread about N/a power
http://www.supramania.com/forums/showthread.php?t=21090

Try this out! You might like to try a Supercharger!
http://www.supramania.com/forums/showthread.php?t=20426&page=9

This is Will's (s383mmber1) ported out intake.
http://www.supramania.com/forums/showthread.php?t=19931&page=4

More info, might give you an idea on how to make a "13.9(s) N/A"
http://www.supramania.com/forums/showthread.php?t=19032

Heres some more on "N/a power!"
http://www.supramania.com/forums/showthread.php?t=19944

Heres a thread with a post by Bishop92t
http://www.supramania.com/forums/showthread.php?t=17807

Some info on n/a-t topic
http://www.supramania.com/forums/showthread.php?t=17497

Heres a good one for mods and gains!
http://www.supramania.com/forums/showthread.php?t=15983

And last, this is the thread that started the section
http://www.supramania.com/forums/showthread.php?t=15977

[7MA61]

http://users.tpg.com.au/users/loats/index.html

Good site for info setup by the previous owner an builder of my car/engine

IMO there is no need for a 3 inch exhaust as 2.5inch system can flow way more then a 3L NA six is ever going to produce, it also helps keep noise and drone down.

[YourEnemy]

hmm speakin of NA upgrades, does anyone know of anybody selling ported intake maifolds?? I know Will did his own, but I dont remember if he said it was a PITA or not.

[AGlobalThreat]

3 inch exhaust is too big. You will lose velocity and scavenging. There is a balance point between backpressure and lost velocity. 2.5 is even pushing it. Yes, it is confirmed. The mod that makes it sound better does not make it faster.

Wrong. Go dyno and come back to us. This is no 1.8l 4 banger, this is a 3l i6, which will increase power going from 2.5" catback to 3". How do I know? Because I did it. 2.5" pushing it? Me along with SEVERAL other people have gotten a great increase in power going from 2.5 to 3 inch exhausts, and this is no "make it sound better but not faster" mod, the gain is obvious.

People will never understand the 7mge :nono:, well, Allan does :icon_surp

[supramacist]

Hey global....., Are you saying you only went to 3 inch from the cat down???

It reads like that.

x87...., Get a dremel. It's not hard to port your own intake and manifold. Don't take the dremel to the head though.

[AGlobalThreat]

Down? Where do u get the down from there is no down in the exhaust system unless ur talking about downpipes ;). I'm talking about a 3" catback, which is the exhaust after the cat

I had a heatwrapped pacesetter header modified with a 2.5" collector, to a 3" catless straight exhaust.

Previous was stock header with a cat with a 2.5" exhaust to a 3" muffler

And no this was not done all at once. First I added the 3" catback which also deleted the cat, then I added the pacesetter header, then I heatwrapped it. All showed distinguishable improvements in power.

[AGlobalThreat]

The thread about the NA running a 13.9 was Dean Marcum in his old NA before he went turbo and 1uz. I talked to him quite a bit when I first got my car and he had quite a bit of work and money invested in the engine and that included high compression, lots of port and polishing/headwork, pretty much every na mod you can think of, some good tires and obviously a great driver. He set the bar too high to reach for most, but for people like me staying NA just started to seem like a waste of money. You'll get to a point where you want more, and your only options are blowing a ton of money on your poor NA to get minute power gains, or to go forced induction. We'll see which you choose ;)

Supras are like a drug

[Nick M]

I don't see your dyno showing the stock piping and that 3 inches, so... where is it?

3 inch will gain top end, at the expense of the bottom, due to a loss in velocity.


IMO there is no need for a 3 inch exhaust as 2.5inch system can flow way more then a 3L NA six is ever going to produce, it also helps keep noise and drone down.
Absolutely correct.


People will never understand the 7mge , well, Allan does
:nuts:

Since you added commentary away from the tech so will I. I was driving a 7MGE in 1989, what were you doing?

[AGlobalThreat]

If you're 1. upgrading your car and 2. know how to drive, and you need bottom end, you are missing either 1, or 2.

Dyno would prove me correct the gains are MUCH MORE NOTICABLE than the loss. I still don't see how you people argue this.

It's a 3" exhaust folks. If you don't want it, don't get it. But I got mine and never looked back.

When I was NA of course

[7MA61]

If you're 1. upgrading your car and 2. know how to drive, and you need bottom end, you are missing either 1, or 2.

Dyno would prove me correct the gains are MUCH MORE NOTICABLE than the loss. I still don't see how you people argue this.

It's a 3" exhaust folks. If you don't want it, don't get it. But I got mine and never looked back.

When I was NA of course
The point is though a 7m with stock cams has no topend so no matter how good the zorst flows the cams pull the power in the top end.

My power flat lines for 1000rpm in the topend. Oh and bottom end is very nice for daily driving, roll on acceleration, getting off the line and hillclimbs all of which make up alot of my driving.

Making a correction to make it compatible to a dynojet dyno/using a 1/4 mile time to project power my car makes close to 185-190hp at the wheels or 155hp on dyno dynamics dyno (approxiametly 30% drivetrain loss).

The car makes peak power at about 5000rpm which then sits flat to about 6000rpm but torque and peak acceleration is dropping off well at this point.:3d_frown:

http://img96.imageshack.us/img96/5595/tuned2ql.jpg

I'd rather ride torque from 2000-5000rpm than worry about revving the car to six thousand rpm when its getting slower anyway.

When I get my cams in and a proper tune I'm hoping to liberate some more topend and further extend the rev limit supposedly good for 8000rpm.:icon_razz

[drjonez]

I'm mainly doing this to 1) help out people wanting to know how to upgrade their N/A's, and to 2) make it so people do not make the usual "what upgrades should I do to my N/A" threads. Below, I'll state what the reasonable upgrades are, what your routes are, and how you can get these parts. Goes from more simple, to mild, to extreme. Mods can edit this anytime if you'd like to organize/tweak this thread.

excellent work, but i disagree w/some statements.



Intake
First, you need to get that engine breathing better. Start giving it more oxygen by adding an upgraded intake to it. The most restrictive part of the stock intake system is the airbox, so buy something like the K&N FIPK to replace the airbox. You can also just get a filter/adapter on Ebay for pretty cheap, I bought mine for $20, works nearly the same.

don't use ebay filters, they suck. buy a cheapo kit, use the adaptor and throw out the filter. get a k&n sized to fit.

you might as well get rid of the intake resonator too, you get that cool NA honking/growl.



Exhaust
This is somewhat of a controversial subject as far as exhaust systems go for N/A's. One thing you need to realize before upgrading your exhaust is that backpressure on a naturally aspirated engine is your enemy! An increase in backpressure will result in a loss of power, which is what you wanna stay away from. So you people with your 3" exhausts, you've actually lost power. The most reasonable size to use when doing your exhaust is 2.5". You're upgrading to a bigger size thus adding abit more power, and you don't have to worry about backpressure. And as far as sound goes, it's up to you on the muffler you want to use and if you want to use a test pipe/cat. I personally kept the stock cat and added a resonator so the sound was more deep and not very loud, sounds great. You can also look into getting a test pipe, but that is illegal in some states/counties and I will not go into any depth concerning that.

ummm, no.

you will NEVER lose max power on too large of an exhaust. back pressure as most think of it, is a myth. what you will feel with too large of an exhaust is loss of response in the lower RPM ranges, but again, you will NEVER lose max power.



Porting/polishing
This is more of a mild mod, but can be the one of the most expensive mods if you go into more and more detail with the shop you choose to work with. Remember when I said flow was the key? It's the same concept here. The stock y-pipe and the intake manifold are pretty restrictive, take the time to hollow everything out (you can polish it if you want bling, and easy to clean areas), to get the best flow possible from your parts.

don't forget about the head as well....



1-piece driveshaft
Everyone has gotten into the situation at one time or another where their carrier bearing has gone bad. Not only does this affect performance, but the weight of the stock driveshaft is unbearable, at nearly 30+ lbs, you have to give alot of effort at times to get what you want out of your car. Get rid of this problem by going with a 1 piece driveshaft, this will put less stress of your effort to accelerate, making the rotation mass less. You can either choose steel or aluminum, but I recommend steel as it's around 15 lbs, aluminum is around 11 lbs, but I personally think it's too extreme if you're staying N/A. Jawsgear is one company that sells these driveshafts, and they're on the forums as well. You can also go to a local welding shop in your area if you want to save some $.

be ready for some more driveline NVH w/a 1 pc shaft.



Raise the compression/build the head, aftermarket pistons
Again, this is advanced modding. Time to go with an aftermarket MHG to raise the compression. Thickness for the MHG depends on how much you need to mill off the head, then you go from there. I'd suggest a 1.2MM HG if you have a normal head/block. If you have alot of warping however, 2MM might be the way to go. Also, buy aftermarket pistons that are slightly bored over, you might as well if you want to raise the compression and get the full benefit of your motor.

stock HG thickness squished = 1.2mm.

there is a TON of stuff you can do to the engine, most importantly being upping compression ratio. shaving the head to up CR isn't the best idea as the combustion chamber gets all wacky then. unfortunately, with the amount of $$ you'll spend on custom headwork and pistons, you could have turbo'd the car and been making 2X the power (not trying to start a war, just giving facts.).



Fuel and timing
If you have done enough mods, you will know that there is always more that you want. Well, a simple way to benefit more from your mods is to raise the stock timing. The stock timing according to TSRM spec is around 10 degrees. Raise the timing to 12-14, depending on how extreme you wanna go (but be warned, you must go with higher octane fuel if you raise the timing). If you wanted to go the extra mile, you could also get an SAFC to fully tune and take advantage of your powerband.

bumping up the timing does help- makes response better, etc. yup, you need high octane fuel. i ran 16 DBTDC for yrs....

there's little chance the GE will ever need more fuel than the stock 330s.




Ignition
To key is to get better spark. High output capacitive discharge sparks ensure complete combustion of the fuel mixture especially at high rpm. You don't want your system to fail because of your ignition system. MSD along with a few other companies make ignition systems for decent prices.

complete waste of time.

change to new some nice new plugs, try opening the gap as large as possible. might as well get some new wires as well. beware of "racing" wires- some actually hurt perf.



Cams
This is a mod for those going the next step. Since you'll be N/A, it's recommended to go with a mild set of cams, too extreme and you won't be running so good unless you have the supporting mods. There is an online website that regrinds your stock cams to around 244 degrees, which is mild enough for an N/A wanting to go the extra mile. http://www.webcamshafts.com/toyota-auto.html

good idea, but cams should be spec'd to work with the rest of your upgrades. again, the same prev. statements re: cost apply....

[SupaMan]

I have a 5spd (if the auto comment was directed toward me) and my car does prolly need a tune up im waiting on 935 for my plugs and wires but its firing on all 6 cly i assure you that my motor is damn near pretty new too was rebuilt about 40k ago even if it was the original motor non rebuilt the car only has 151k miles on it.

Im not sure if i wanna spray it or not i might i might not this is my only car right now so i prolly wont spray it until i have something to fall back on.

I didnt say i was racing it that way it was something i noticed when id be fuckin around and floor it in 3rd doin like 30 mph id never race like that would be retarded. thanks for explaining why it does that tho global.

my car is still pulling hard when i shift around 6300 or so but i didnt buy my car to race it i bought it because i love supras and it was a steal of a deal. :)

it keeps putting my shit here on page 3.........eh fuck it

[SupaMan]

my car doesnt have that much low end as it is if you punch it in like 3rd at 2500 it doesnt really start to get a move on until about 3500-4k. Im deff gonna put my car on the bottle later on but its not gonna be a huge shot prolly a 50 or 75 if i get a lil juice happy.

[Nick M]

Dyno would prove me correct the gains are MUCH MORE NOTICABLE than the loss. I still don't see how you people argue this.


Did you ever stop to think that other people actually drive their car on the street, and spend most of the time between 2000-3000 rpm? Probably not.

If you have an engine that you have done up like defiant, then by all means, you can use a bigger diameter exhaust. Something that matches the output of the engine.

[supramacist]

Oh thank god. I didn't want to say anything because I couldn't tell if I said something or if supaman did it. If your ride doesn't come to life till 4k rpm's...., I would say it either has a 4 cylinder or I would ask when your last tune up was. A full service tune up, not a half ass'd replace part of this and that. I mean plug wires and all kinda tune up. I sure wouldn't hook nos up to anything that was already beyond half of it's life expectancy unless you just want to blow it up.

All of you turbo and nitrous happy heads can keep that shit. You drive a naturally aspirated auto. If you wanted more umph you should have got the mclaren. Or atleast a nissan. Jeeeeeez. Everyone is always bitching about my car isn't fast enough. When you all should be bitching because you didn't do your research, half of you probably impulse bought and found out later it's not what you thought it was. it's like beating a dog because it got to old to play with you or some shit.

[AGlobalThreat]

The point is though a 7m with stock cams has no topend so no matter how good the zorst flows the cams pull the power in the top end.

Nope. Advanced ignition timing (I used 14 btdc, Dr. J used 16 btdc) and a free flowing exhaust will have the NA pull hard up to redline. I never upgraded my cams and getting rid of the power drop off up top was one of the first things I did to my NA. It made the car much more enjoyable.


my car doesnt have that much low end as it is if you punch it in like 3rd at 2500 it doesnt really start to get a move on until about 3500-4k. Im deff gonna put my car on the bottle later on but its not gonna be a huge shot prolly a 50 or 75 if i get a lil juice happy.

That's your ACIS (air controlled intake system iirc) valve that allows the flow of more air to the intake right around 4k, which is why you feel the boost in power

You guys need to learn how to properly rev match and downshift so you can take advantage of your cars powerband. Just simply cruising in low rpms and punching it will be good for passing cars, but that's not how you win races.


All of you turbo and nitrous happy heads can keep that shit. You drive a naturally aspirated auto. If you wanted more umph you should have got the mclaren. Or atleast a nissan. Jeeeeeez. Everyone is always bitching about my car isn't fast enough. When you all should be bitching because you didn't do your research, half of you probably impulse bought and found out later it's not what you thought it was. it's like beating a dog because it got to old to play with you or some shit.

Hey now, NA people want to go fast too. If you don't want to upgrade your NA, then plain and simple, stay out of the NA upgrade thread. I bought my NA because it was a good platform to start and was just what I wanted, 2 door, 6 cylinder, and rwd. Did I care that I had less power than the turbos that sell for $2000 more (Got mine for $1400 :))? Heck no, the NA supra is a great place to start and I started building it from day 1. I modded the crap out of it until the point where there was no more weight reduction left to do, the engine bay was cool to touch, and if it weren't for blowing my engine up on a 150 run I would have finished the car with a nice dyno tune and just enjoyed it. I loved my NA engine and the only reason I went with a different engine was because I wanted to go faster, and isn't that what EVERY person who mods a car wants? Nobody is saying to ditch the NA, this thread is for modding it, and there is more than enough information here to make a fast NA

[Kai]

Question - i'm at 12' timing (it was at 8' for some reason and barrelled through fuel at an astonishing rate), but it feels like the power is off lower down - is this the case, or is it really old plugs and valve clearances needing doing that causes this?

[Nick M]

It depends on what you consider top end also. The stock 7MGE should pull hard to redline, but redline isn't very high either.

[7MA61]

It depends on what you consider top end also. The stock 7MGE should pull hard to redline, but redline isn't very high either.
Limiter is set at 7000rpm for me, it'll tag it happily but in 90% of circumstances your better off shifting into the next gear at 6000rpm because torque drops off very quick.

The only instance I've found is useful was on a short hillclimb course, it wasn't long enough and with corners coming up to demand 3rd so I just sat in second gear just before the limiter, then backed off into the corner and jumped back on it again afterwards.

I can rev the car out but the shove in your back when you punch the next gear and the rate of accelration increases dramatically tells me I should be shifting well before the limiter. Remember torque determines how fast a car accelerates and if you look at most graphs it drops off significantly at 5000rpm, hell I have more at 2000rpm then I do above 6000rpm:biglaugh: .

[supramacist]

Right on man..., I agree. It's just if your'e going to want a turbo. Why not do it and get it over with. There's no need to get Dr. Frankenstien on it. No disrespect intended. If what I said doesn't fit you it'll fit someone reading. I bought the na because I knew I didn't want the turbo. Because I know I'll spool it and this will make me want nos. I'll end up picking up trash on the side of the road to work off the tickets. I also think that if they don't want us doing it on the streets, we should be supplied with a place to do it.

Again. These are only opinions and there is a reason they are free.

[Ma70.Ent]

This thread has been stickied. The first post needs some editing though because some of it has been proven slightly false. That, or people can just read the whole thread.

[Ma70.Ent]

hey supaman i have a question for you have you gotten ur spark plugs and wires from 935 yet?

You should PM him or something, because your post has nothing to do with this thread.

[Boss302]

There are some people with 3'' exhausts who have felt no power loss at any point. So I don't think you should be saying this unless you really confirm it.

2.5 offers better restriction which is what's needed in our N/A cars ask any mufflershop.


Also... Advanced timing to 14-16 BTDC if you run premium 91-93 (which you should always) always helps.

running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.

[GotToyota?]

Cool, I never noticed that the thread got stickied!

[Ma70.Ent]

running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.

You're late. Read this whole thread about the exhaust.

Also, I never said higher octane made your car faster. I said you needed to run high octane if you ran 14-16 BTDC timing.

[Tanya]

high octane makes it so you keep the small amount of HP you "gained" from advancing timing. without the higher octane, spark knock would probably occur under certain conditions and the knock sensor will go off, retarding the timing, and effectively you'd be "losing" the hp from timing advancement

[drjonez]

2.5 offers better restriction which is what's needed in our N/A cars ask any mufflershop.

heh. no.




running premium fuel on our cars yeilds no real performance gains high octane fuel gains only come into play on the higher end of the comp. ratios 9.5 and so. i know this because i saw a demonstration on horsepower tv where they used different comp piston until the reached 9.5 there was NO difference worth chasing after.

you're missing his point- jack up the timing and you DO need higher octane fuel.

[GotToyota?]

you're missing his point- jack up the timing and you DO need higher octane fuel.
Exactly. If you don't, you'll be pinging like crazy, and then you're in trouble.

-Matt

[Boss302]

ah proven wrong thank you

[Nick M]

This looks like a nice place to expalin Toyota's air intake control system, or ACIS as it is now called.

First of all, it does not ever "kick in". The default position of the valve is springloaded open, which is high rpm use. Vacuum pulling on the diapragm closes it to boost low RPM torque. The manifold with longer runners aids low end torque, but starve the engine at higher engine speeds. The shorter ones lose velocity, but can fill a cylinder at high RPM.

So the system is set up for high rpm, and closes the valve for low speed torque. If you really feel it kick in, your probably does not work, and the vacuum solenoid is froze. Take a good look at that stock torque curve, and how flat it is.

That is stock and working correctly. Jetjock has posted the parameters for specific opening and closing elsewhere, but now you know why.

[Ma70.Ent]

Thanks for posting that. Anyways, this is what he was talking about:


Maybe this will help. I don't have one on my car but this is what the tech manuals say:

The ACIS is designed to shift the torque band higher along the rpm range. It does this by responding to changes in the throttle opening angle (VTA signal of the TPS) and engine rpm (NE signal in the CPS). The air control valve is then opened or closed by the ECU via a VSV and vacuum actuator.

The valve is located in the center of the manifold and when closed divides it into two sections - a front chamber for cylinders 1 to 3 and a rear chamber for cylinders 4 to 6. A closed ACIS valve has the same effect as lengthening the intake manifold while an open valve has the same effect as shortening the intake manifold. In other words flow efficiency what's being controlled.

When the ECU turns on the VSV vacuum is applied to the actuator and closes the valve. When the VSV is turned off atmospheric pressure is applied to the actuator and opens the valve. There are four combinations of speed and throttle angle the ECU uses to decide when to open or close the ACIS:

1) Above 60% throttle angle and above 4,200 rpm: VSV off, ACIS open.

2) Above 60% throttle angle and below 4,200 rpm: VSV on, ACIS closed.

3) Below 60% throttle angle and above 4,200 rpm: VSV on, ACIS closed.

4) Below 60% throttle angle and below 4,200 rpm: VSV off, ACIS open.

[Smeg!]

I've heard you can use the throttle body from the 1UZ with some minor mods, it this true? anyone done it with actual results? Anyone know what size throttle body is used on the 1UZ?

[tonystarks]

so can turbo pistons be used in our NA's? I have been trying to search for this for 45 minutes and got fed up!! So any answers would be appreciated. I priced a set of JE's for around 800 dollars. IDK if any suggestions pm them to me so I dont jack this thread.......:1zhelp:

[YourEnemy]

so can turbo pistons be used in our NA's? I have been trying to search for this for 45 minutes and got fed up!! So any answers would be appreciated. I priced a set of JE's for around 800 dollars. IDK if any suggestions pm them to me so I dont jack this thread.......:1zhelp:
yes you can.

[bluedragon17]

yes you can use turbo pistons the only difference is they are lower compression than NA pistons so you will notice a loss in power

[YourEnemy]

yes you can use turbo pistons the only difference is they are lower compression than NA pistons so you will notice a loss in power
a lot of people will do this if they are going NA-T

[tonystarks]

I was planning on just going turbo but instead am just going to go all forged and spray a little bit. I just want something reliable and occasionally take it to the track :naughty:

[7Mboost]

Just an idea on a possible addition which I have no idea about, pullies...?