Analyze my Dyno

[Boostage]

Tell me if I need to go 1.5j or just go down to a .70 backhousing..

Specs:
1jz
Crower Small core 272 cams springs retainers
Garrett 60-1 with .84 divided housing
Divided Manifold
Stock cam gears
3" IC and piping
3"DP and Exhaust
Blitz ECU
SAFC II


Boost was only at 14 lbs which clearly reflects in the lower TQ. Eventually Im going to up the boost, but that will probably make a bit more HP but wont help with the low end tq. Im curious to know. if I drop down to a divided .70 a/r exhaust how much will it help the low end TQ? I am hoping to get about 180-200 or so TQ by 3k. seeing that stock twins makes 200-220 foot lbs at 3k. will an a/r reduction to .70 be enough or do I need adjustable cam gears, smaller piping etc? or do I need to just get a 2jz bottom.

The motor is so strong up top but Lacks the low end pull I am looking for when daily driving. under 4k it just feels weak.

 

[RockPaperSwoRD]

well cams shift your curve to top end, a bigger turbo also adds to spool time so the only thing you can do is go 1.5jz, also you can try changing your rear end, what gear ratio do you have now? try upgrading to the 4.3lsd

 

[Boostage]

Rear is 3.9 Infinity j30 diff in a 240.. sorry my car is not a supra

 

[Poodles]

The different turbine housing is the cheaper route, more than likely it will help the situation. Putting a 2J block will help a whole lot as well, but I'd start with the turbine housing...

 

[suprafanatic]

If it was a 7m you wouldnt have any low TQ problems

 

[queenskid926]

a lower backhousing will help. If your are going 2j bottom which bottom where you thinking of using? I know a few ppl that are usng the 2jzge bottom, some more compression that a gte so your turbo spools faster, you get the trq that your looking for, and off boost, the car makes more power due to the slighter higher compression, but just he the 2jzgte, the 2jzge block can handle the power

 

[Supra-Man18]

(as seen on annoying robs sig )

LEARN IT, UNDERSTAND IT, DRIVE IT !!!

 

[hottscennessey]

I personally wouldn't go to a smaller hotside.

A standalone ECU and an EXPERIENCED tuner will help your spool time, but I wouldn't expect a dramatic difference.

You will see the best results from the standalone ECU, and a 3.0L block.

I personally wouldn't go 1.5JZ without a standalone ECU. That's my opinion. Take it or leave it .

 

[Turbo Drifter]

I personally wouldn't go to a smaller hotside.

A standalone ECU and an EXPERIENCED tuner will help your spool time, but I wouldn't expect a dramatic difference.

You will see the best results from the standalone ECU, and a 3.0L block.

I personally wouldn't go 1.5JZ without a standalone ECU. That's my opinion. Take it or leave it .

I would have to agree, well said.

 

[RacerXJ220]

well cams shift your curve to top end, a bigger turbo also adds to spool time so the only thing you can do is go 1.5jz, also you can try changing your rear end, what gear ratio do you have now? try upgrading to the 4.3lsd

If your cams are set to spec per the cam card, then I would just leave it alone. My crower 272 large core exhaust cam HAD to be adjusted per the cam card in order to run correctly on my motor. Maybe it's just a large core issue, but setting the cams is a good thing.

I do NOT like the original crower 2J regrinds, the exhaust cam is the only one that fit close enough for comfort, and should be checked.

I just got back from the dyno just now. Setting the cam straight up with stock gears the motor just ran like shit.

 

[RacerXJ220]

under 4k it just feels weak.

1JZ w/single issue IMO. A 2JGE block with a stock TT HG should fix that.

 

[Turbo Drifter]

1JZ w/single issue IMO. A 2JGE block with a stock TT HG should fix that.

I agree, I have had both a 1jz big single and a 2jz with a comparable turbo. The bottom end off boost and low boost is night and day.

Load cell tuning a car is vital to get the best bottom end and low boost tune. The difference can be amazing, with safely load cell tuning the timing and fuel you cam get huge increases. Like going from 60ft/lbs at 2000rpm and 100kpa to 85-90ft/lbs at the same RPM and load (all numbers are examples). Its really quite impressive and can make the car a joy to drive.

Jeremy

 

[becauseican]

The .84 T4 turbine housing is the problem....that is huge for a 2.5L unless you are making 650+ HP. I run a .58 T4 turbine on my T61 and I love it!!. Its making 420 ish HP at 18-19 psi and not choking yet, it may at higher PSI (22+) I will find out soon enough. Typically I use .58 turbines on quick spooling 400-450 Hp street car builds or the .68-70 for higher power/ higher boost builds. The 1jz doesnt have the exhaust flow of the 2jz, so you have to keep the velocity high to spool the turbo, so a smaller housing is best. Ever seen the exhaust ports on a 1jz???, they are tiny, just over 1", designed to keep the exhaust gas velocity high.

 

[tekdeus]

How big are the wheels on a 60-1 by the way? I think it would be safe for you to pull the trigger and try out the SP quick spool valve. I think you'd get 300-500 sooner spool. You've seen how crazy fast the boost and power is rising on my dyno graph when the valve is closed. I'm running a T4 .84 turbine with a 62mm compressor and 68mm GT turbine wheel on a stock 3.0l 7M. Currently getting 15psi at 3600rpm and once I get the valve to hold closed longer I should be able to get 15psi at 3300-3400. But it is billet and ball-bearing, so those help spool a lot as well.

The effective A/R of your .84 housing will be similar to a .42 or .58 when the valve is closed, so you get the best of both worlds.

But as Randy said, he has success with the smaller housings and not losing much top end anyways, so any of these options will still improve spool.

The 1.5JZ would be the better option, and combined with the spool valve should have around the same spool as my setup.

 

[Zazzn]

no it's also the turbo it looks like he may have a clipped exhaust, as well..

Do you're self a favor,, buy a better turbo...

Buy GT35R or something very similar if you are t4...

IF you can step down to a T3 I bet you will be happy.. 35R will make 600 WHP on race gas. 450-500 on pump gas with your setup and be fully spooled by 4k....

 

[suprahero]

How many others on here have 3" intercooling pipes? That seems awful big to me for a 1jz. I have the pt67 and a 1.5jz and still only have the 2.5" piping. Maybe I need larger piping.

I also second the gt35r suggestion. I made 473rwhp @ 18psi on my 1jz with the same cams and retainers that you have.

 

[F&H Performance]

2j bottom imo. But a 35r is a great option if you plan on leaving it 1j, if you go 2j a 40r would be sweet.