2jz swap turbo questions

[yongai27]

hey guys,

im doing a 2jz swap! hooray! anyhoos, my goal is 550 whp. I do have a dilemna though. I cant decide if i want to go upgraded twins (two disco potatoes <3 haha) or go a single t62 and milk that to 550. (first world problems -.-)

I was thinking that having boost EVERYWHERE would be super fun and sweet with the upgraded twins, but sort of kind of limiting. Also there is that much more than can go wrong in my car if i stay twinned. Also i heard fitting the twins into the mk3 chassis is REALLY HARD.

On the other hand, a fat single turbo seems like the iconic supra thing to do. Get tons of hp, less things to work on, less things to go wrong. Seems harder to drive. But one huge push is fun, I have that right now with my 7mgte (57 trim).

I would really love to hear your guys' input on this. Keep in mind that this is my daily driver, so i dont plan on anymore hp than that.

Thanks!

so far this is what i have from you guys:

Single advantages
Easy power
Cheaper than twins
Easier to work on
Cleaner
Less thing to go wrong

Single Disadvantages
not having boost everywhere?

Twins advantages
boost everywhere
dont need all the stuff you need to go single


Twins disadvantages
Low top end power
basically the advantages of single lol.

 

[Grandavi]

First.. bear in mind.. I am not an expert, mechanic, etc.. just another fellow Supra owner, so my comments are just that. They are from what I have researched.. not practical application.. but you asked for input.. so .. this is my 2 cents.

Personally I have never heard of a twin spool 550 on a 2jz inside a MK3 shell. Seen it on a dragster, but that was a 7M (close enough). I think the double idea is far more complex and expensive than you would want (if it is indeed possible). Been done on singles.. so I would go the path more travelled. Also, I think you want to seriously consider water/meth for detonation control at 550+ (that's only from reading, not from rl experience). Start a build thread! I like watching these.. : )

Finally, remember.. it isnt solely a turbo to get you there.. you have to control it and feed it. And the farther past 400 hp the more control your engine has to have, small issues at higher HP will cause larger problems (kinda like a bigger grenade idea.. lol). And for god sakes.. dont get to 550 without considering how your gonna start and stop...

 

[yongai27]

ahahha yeah ive considered brakes and everything, thanks for the reminder though. im pretty sure I dont need water meth for 550 hp. according to albert and driftmotions site, http://store.driftmotion.com/static/i-2jz-gtearistotwinturboupgrade.php, 500 is within the capabilites of the twins, (obviously with the supporting fuel mods).

What i wanted to know was your guys opinion of bang for buck, what car would be more fun, advantages/disadvantages of twin or single etc.

 

[hvyman]

I'd go with the single. It's going to be hard to hit 550 wheel and have top end with twins. Plus you have to bang the firewall.

Single is cleaner and easier and IMO more fun.

 

[travweek]

im doin a 1jz twin upgrade and 550 is is not hard to get at all...i will say it is very expensive. i got two garrett gt2871 for 1400 and my manifold has to be fabricated so i wont have any surging issues with the down pipe and add an external waste flange i pinched out 550 for all that to be done mine u the manifolds cost me $300, aem v2 $900, 1000cc injectors got from a sm member for 250, bc cams 272 $580, 14mm fuel rail $180, labor i do myself except the fab work! but u can see like i said its expensive compared to a single that u can get everything u need for 1600 n piggy back it! but my setup looks almost like this except he has surging issues cause his manifold weren't connected! they actually make the manifolds for 2jz with some even come connected with external gates added http://www.bicperformance.com/used.htm

 

[yongai27]

hmmm i edited top post gonna make an advantages disadvantages list for people who just wanna read first post

 

[yongai27]

I'd go with the single. It's going to be hard to hit 550 wheel and have top end with twins. Plus you have to bang the firewall.

Single is cleaner and easier and IMO more fun.

oh by the way, i was planning on doing a stock swap first, then upgrading, because im not that knowledgeable about 2js, and i didnt wanna upgrade a whole bunch of things, and if something goes wrong, i wouldnt know wth it is. Also, I wanna see if the engine is in good condition before i do anything to it, so i can return it if otherwise haha. BUT i dont wanna bang my firewall. so should i just go straight single before i swap it in? what do u think

 

[hvyman]

1 the twins are a huge pain in the ass to take off in the car.

2 single is easy. Dm sells kits for like 1500. Prolly pay around the same for upgrading the stockers.

3 make sure the stock Jdm ceramic shaft turbo are even good before using then.

4 can Pull the pan and valve covers and do a visual. If everything is clean or has a yellowish tint to it the motor should be fine. Just prime the oil system before starting.

 

[travweek]

1 the twins are a huge pain in the ass to take off in the car.

thats for damn sure!!

 

[te72]

If you can swing it, go for a modern ball bearing turbo. Size it properly, and you'll do well. Think about it this way: Would you rather have good power down low and in the mid range, or make an engine that sacrifices 1000rpms of usable power to make your top end goal, while only using 60% of the turbo's capability because you bought a huge single?

Personally in my experience, it is more fun to have power in a useable power band than it is to be in a car with massive amounts of peak power. Often faster too.

 

[yongai27]

If you can swing it, go for a modern ball bearing turbo. Size it properly, and you'll do well. Think about it this way: Would you rather have good power down low and in the mid range, or make an engine that sacrifices 1000rpms of usable power to make your top end goal, while only using 60% of the turbo's capability because you bought a huge single?

Personally in my experience, it is more fun to have power in a useable power band than it is to be in a car with massive amounts of peak power. Often faster too.

isnt that sort of powerband achievable with the twins? or are the twins just a no go? I do have a budget haha. the max id be willing to spend is 1200 on a turbo setup. Albert's twins are that price. If i go single, id find most of the stuff used, except the turbo which id like to buy new.

on another note, i could just wait even longer for my swap parts until i have enough money to throw down for a sweet turbo, but that could take a while as im quitting my job and starting school again -.-

 

[hvyman]

It's all about turbo sizes. If you get a smaller turbo with a small exhaust ar it will spool fast. Also divided manifolds and housing will spool faster as well.

 

[yongai27]

I was thinking a t61 would be the smallest turbo to hit my goal of 550. or could i go with something smaller? i was planning on running 550 injectors and the other supporting stuff. and a megasquirt for management. Thanks for info, i really appreciate it.

 

[hvyman]

To hit 550 your going to need 680 or bigger injectors.

Could start with a t61 and a small ar housing and see where it gets you. Even 400-450 at the wheels is going to be fast.

 

[yongai27]

oh thats weird, Amar told me i only needed 550's that day we met at k1

 

[te72]

Hitting 550 on Albert's twin setup... I'll be honest, if it is possible, he would have to be the one to fill you in there. I'd be highly impressed, but I don't see it being out of the realm of possibility at the peak output of the engine. Plus, you would retain good low/mid range too.

I actually would have went with an upgraded twin setup, if not for the fact that I LOATHE the turbo piping for the twins... Plus I wanted a ball bearing turbo, not sure if Albert's setups allow for ball bearing.

Albert? Paging Albert to the thread...

 

[hvyman]

oh thats weird, Amar told me i only needed 550's that day we met at k1

You can but it's going to max them out.

 

[yongai27]

Hitting 550 on Albert's twin setup... I'll be honest, if it is possible, he would have to be the one to fill you in there. I'd be highly impressed, but I don't see it being out of the realm of possibility at the peak output of the engine. Plus, you would retain good low/mid range too.

I actually would have went with an upgraded twin setup, if not for the fact that I LOATHE the turbo piping for the twins... Plus I wanted a ball bearing turbo, not sure if Albert's setups allow for ball bearing.

Albert? Paging Albert to the thread...

What setup do you have right now? How much power are you making and where? =) thanks!
Albert didnt specifically say if his were or werent capable of 550, he said that people were making them on upgraded USDM twins. They could have been someone else's i suppose haha

You can but it's going to max them out.

ahh ok coolios

 

[Heartbeatracer]

you answered your own question, you say you have a budget right? I know for a fact twin is just setting yourself up for huge problems in the future. I am switching from twin to single, for 2 reasons, more power and practicality, and less problems. If the twins go down... oh boy problems problems problems.

I had a mazdaspeed 3 and an Audi S4 twin turbo. I had the Audi for about 3 months, never raced it hard, would do a highway pull maybe a couple times a month. After the 1st month had all sorts of problems with the turbos, I bought the car for 6700 and paid 4500 to have parts and paint. And did all the install work myself on the body. the engine was practically new with 24,000 miles on it. I ended up spending over 5,000 dollars replacing the parts and pieces of the turbos and getting the car running right after the first month of getting the car back on the road.

Mazdaspeed 3, single turbo, went GT35 Turbo, never had a single problem, on either Turbo pushing the car to it's limits... I was getting boost peakage of 24psi on the stock turbo!

anyway, after fussing with both kinds of turbos in the back, my decision to go single was because of those two reasons. I'm not a Supra Tech, or have even driven my supra yet (( but just sayin

 

[te72]

What setup do you have right now? How much power are you making and where? =) thanks!

Sorry I never got to you. Running stock CT12a's, the only mods I have are the cams, head porting, 3" exhaust from the turbos back, and at the moment (while it's still warm enough anyway), a Turbosmart boost controller. I would estimate anywhere between 320 and 360whp, power comes on nice and hard anywhere from 2800 and above, pulls all the way to redline.