I made 480 whp on a sc61 on 1000cc injectors about 2 years ago . I just had the turbo rebuilt and installed id2000 injectors and a new pump to get me to that 500 mark. But on the same dyno with same turbo on same boost I made 120whp less . Leak down and compression test were both same as 2 years ago . My question is if im hitting same boost levels but have a boost leak could it be the cause ? When i got home i found I was leaking boost were the injector meets the intake manifold. Car would make strong power and hit about 6k and flatten out. Thanks

 

That would have to be one major boost leak to drop 120whp.

Who rebuilt the turbo? Do you have boost logs between this session and two years ago?

 

Precision turbo did the rebuild . I don't my tuner might though I'm looking into it.

 

what about ambient temp, humidy, dyno calibration (if its the same one), afr's in each setup, same exact turbo/intake mani's? list goes on bud

an to 100% honest if your inj had a vac that bad at inj and he /she couldnot pick up in that via a lean reading from get go you prob need to find a diff tuner

 

Dyno same not sure about temps and humidity but a cool night, ait never got too hot and afr under boost always around 11 and at idle 14-15 manifold same only change was injectors and pump . Really has me thinking turbo . But no smoke or shaft play.

 

no i ment were ALL the things i listed EXACTLY the same?

 

going to such a drastically large injector reduces atomization of the fuel. that alone could be a large contributor to the power loss.

WHY did you go from 1000cc to 2000cc? 1000cc should have absolutely no problem hitting 500whp. hell they should hit 700 in a lot of cases.

that boost leak might drop your power by 5-20hp, but definitely not 120hp.

are you using the exact same ignition settings as before? if the tuner messed with ignition they may have altered things in a bad way.

its also possible that the 480whp was SAE corrected power, and the new low number was NOT corrected. or vice versa

 

Thanks for the input guys gives me some things to talk to my tuner on.
I guess my question really is if turbo is spinning faster to build the same amount of boost as before would that result in a drastic loss like that?

I went with id 2000 i was on some pte 1000 that were at 98% duty cycle and dyno is same and correction factors same as well .

 

Fix your leaks and head back, but my inclination is that you've somehow lost the VTEC crossover.

 

it would result in a power loss, but not a 25% power loss.
the power loss would be similarly equal in percentage to the amount of air leaking out. a leak at the injector seal would in no way make up for 25% being lost. 2% at most, maybe.

 

Yea something isn't right here.

verify all of the injectors are functioning properly. I'd send them back and have them flowed, cleaned, reflowed, then balanced... as just swapping injectors (unless you didn't re tune it) would not cause that much power loss

can you tell if the motor is getting up on the high cam and high cam fuel/ignition tables? If not, then that could very well be what the problem is

and like others have stated. fix all of your leaks/issues and go from there

also when was the last time the fuel filter was cleaned/replaced? Also the filter sock in the tank could be full of debris, or you're simply out of fuel pump (it doesn't flow enough for the new injectors and tune) Do you have a fuel pressure gauge? either on the rail or in car? if so do a dyno pull and see if the fuel pressure fluctuates or drops

 

^yes, that too for sure^

 

yea I mean if nothing changed but an injector swap, higher boost/more power and a tune then all I can think of is that it is an issue with something in the fuel system or he doesn't have enough fuel pump for the new injectors and power level. I'd be willing to bet that at higher rpms under load the fuel pressures bounces around or even drops off harshly