dyno today (picture)

[jtjerry]

You must be logged in to view this image or video.

today I dyno my car. It is 1993 mitsu colt (mirage) GTI. It has 1990 4G63T engine from eclipse.
Max boost was 1.2 bar (17 PSI)
max HP was 210 SAE net (165 hp on wheels) at 6065 RPM
max torque was 315 Nm (233 lbs) at 3535 RPM

at 3400 start strange torque drop . I saw too at that point my pressure start dropping from 1.2 bar to 1 bar at full boost. There is always at that point strange but nice hiss sound from engine compartment. I done pressure check and pumped 1.4 bar and no air leak at closed trottle body. Can that be my blow off valve not holding pressure?
What do you thinking?
thanks for answers
Sorry for my English...
Jerry, Poland
btw engine is stock 14b turbo, MBC.

 

[Mirage2LTurbo]

Could it be the vacuum line going to your bov, if it was cut, the vacuum would cause your bov to open under boost, correct?

 

[jtjerry]

do not understanding...
my bov is stock connected...

 

[Talondsm18g]

Ur supposed to boost test with the throttle open fully. You could have a manifold leak or a tb gasket leak or vac line in that area.

 

[97EclipseGSX]

Injector to head seals had me whooped for a little while can't really see down there well but they were screwing with me under boost. Might wanna check them if you have messed with ur rail or injectors and not replaced them.
Also, maybe a stuck open PCV valve.

There are so many things it could be. Did you spray everything with some sort of soap and water while testing? You will be surprised what can leak and not make enough noise to hear.

 

[jtjerry]

thanks guys
I done leak test with tb open too.
At about 12 psi there is some ecape at tb. but not much.
How check that bov is good and holding boost?
what do you thinking? At 18 PSI there should be more power that 210 HP...?
Jerry

 

[myblack98gst]

kind of looks like the exhaust may e a problem I dont know what you have but it seems like it is kind of small to make that much torque at low rpm. but power drops off at the end..

If you have full 3" maybe the turbo is getting weak and cant keep up at high rpm?

who knows...

maybe it just needs alot of tuning

 

[jtjerry]

exhaust is 2 inch without any cats.
Jerry

 

[myblack98gst]

you may want to go ahead and crank that up to a 3" you will see quite a bit more gain from doing it that way

 

[kazzam]

yeah dude, a 2inch exhaust isn't good for a turbo car, it would be a very good idea to get at least a 2.5, but a 3 would be best. U will see major gain from bigger exhaust. Make sure your turbo actuator is working properly!
If u want, u can disconnect the exhaust at the o2 housing and see how it is, it should be alot more power. Just an idea on how much exhaust will help.

 

[DSMSpyder99]

i agree you need to get a custom 2.5 or 3 inch exhaust made depending if your gonna upgrade to a bigger turbo. I would say if you get anything <16G 2.5" piping, >Big 16G 3" piping

 

[Black95TSIawd]

2.5in exhaust....up to 350hp, 3.0in exhaust....350hp+. See what your needs are and then go for it. Yes 2in is small but, 3in is not always needed.

 

[jtjerry]

I will make 3 in all the way.
Jerry