2JZ power issue

[Desrosiers]

Hi,
i have a 2jzgte vvti gt4088r powered is300 with ms3x ver. 3.57.
The car run fine and smooth to drive but that not a gt40r power, the engine feel like chocked and even on neutral the car has difficuty to hit rev limiter.
I have a 3 inch straith pipe exhaust with varex muffler and 2 ½ inch intercooler pipping. With my old setup in don't have any issue power. I switch from TEC3 to megasquirt and change my 60-1 turbo to gt40r and i lost power. That's a probleme.. The turbo was brand new and he spool very fine but even i first gear without a big clutch kick, no tire slipping :/ and i run 16 psi off boost.

What's checked:
Timing is fine 10 degres in fixed duty to rev limiter: good
Timing belt is OK no tooth off
Compression 175psi to 178psi on hot engine: good
Plug BKR7E gapped at 30: OK but the plug are VERY black
AFR on boost was between 11.3 and 11.8
No boost leak detected

any idea?

[BigLou240sx]

When you say difficulty hitting the rev limiter, do you mean 7500 rpm or 7350?

You have a soft limit enabled at 7350 that retards spark to 1 degree, and appears to be doing a solid job of keeping you off 7500 rpm.

As far as less power though (during full throttle/boost), nothing is really jumping off the page for me as long as timing stays steady across all RPM and has been verified with a timing light and compared to the commanded timing.

Your throttle application after the shift looks very strange though - you are full throttle for 0.4 seconds but RPM drops from 6000 to 4700 RPM. The VE1 at that point is around 90 during this point, where at full throttle and 200kpa, your VE is actually less. I would expect that this is too much fuel for 93 to 150 kpa in your table and should track better to your ve at higher boost.

As a general note, recommend smoothing your VE table a bit.

[billr]

The spark-plugs are "VERY black"? That's usually a good hint that it is running far too rich. Since the VE values seem low, I gotta ask... have the injectors been flowed (with you drivers) so you know the accurate flow rate and dead-time?

[Matt Cramer]

Check the timing with a timing light to be sure it is correct across the rev range. If it retards at high RPM, increase the spark latency setting until it is correct.

[Desrosiers]

Check the timing with a timing light to be sure it is correct across the rev range. If it retards at high RPM, increase the spark latency setting until it is correct.

everything is good on this side. the timing stay stable to the rev limiter

The spark-plugs are "VERY black"? That's usually a good hint that it is running far too rich. Since the VE values seem low, I gotta ask... have the injectors been flowed (with you drivers) so you know the accurate flow rate and dead-time?

i run siemens 3145 injector (750cc low impendence) and i used digikey resistor to connect to ms3.
i put 1ms on the deadtimes setting

[Desrosiers]

Anybody has an idea?
A problem with ems?
Wirring?

[billr]

Same question as before:

Have the injectors been tested for flow and dead-time using your fuel pump/regulator and injector drivers?

[yzn]

Did you check for exhaust leak and wastegate leak?, as it reaches 1 bar of boost nearly at 6000 rpm, i don't think a gt40 turbo would reach this boost that late on 3 ltr engine

[Desrosiers]

Same question as before:

Have the injectors been tested for flow and dead-time using your fuel pump/regulator and injector drivers?

How can i check that? Flow bench?

[Desrosiers]

Did you check for exhaust leak and wastegate leak?, as it reaches 1 bar of boost nearly at 6000 rpm, i don't think a gt40 turbo would reach this boost that late on 3 ltr engine

No prob in this way! I reach 1 bar at 4000 rpm

I try to play with vvti setting but no change in this side

[billr]

No, you do not need a flow bench to check injector parameters. In fact, for dead-time you don't even want to use a flow bench. You need to check dead-time using your injector drivers. Those parameters can be measured using Tuner Studio, along with some way to collect fuel under an injector and measure the fuel collected, either by volume or weight. With a bit of ingenuity that can be a low-buck (and very accurate) project, but a bit tedious. I did a quick look for a good description on how to do those tests, but couldn't find one. Will somebody else post a link to flow and dead-time testing?

[jsmcortina]

Try this: https://www.youtube.com/watch?v=lJgi8l-2XG4

James

[Desrosiers]

Thank! Very useful
I'll try that next week.

And for the vvti if i put 50% of duty cycle i get 0 degres right?
0% 30 degres retard and 100% 30 advance?

[jsmcortina]

No, the VVT doesn't work like that at all.

James