doc

I've a problem with my fresh build turbocharged engine.
When accrelating, boost builds around 4000rpm, got almost full boost at 5000 rpm (8 psi, wastegatespring is a 9psi one) and feels strong until 6000 rpm. At 6000 rpm and above the engine feels asleep. It takes ages to go to redline.

The setup:
B20VTEC (sleeved block) & CP 9:1 Pistons,
ramhorn style manifold,
SSAC Super T70 (please don't let get this in a SSAC hater thread, let's say it's a big turbo),
TIAL style wastegate with 9psi spring (no SSAC),
HKS Stye SSQV BOV (no SSAC),
ITR IM & TB,
Spearco FMIC,
Hondata Heatshieldgasket,
3" exhaust from turbo to endtip,
Dumptupe ends under the oil pan,
stock fuel pump (walbro will be installed tomorrow),
880cc injectors,
stock FRP, gauge reading 40PSI at athmosphere,
streettuned with ProECU.

Not dynoed yet, but it feels defianatly weak. It want break loose tires even in 1st gear (my other turboed car, heavy CRV with B18C6 turboed with T3/04E running just 6psi break loose tires!)

What i checked so far?
Cam timing = OK,
Ignition timing = OK,
tuned to Lambda 0.8 (= A/F 11.8), even tried richer and leaner conditions,
tried ignition tuning up & down = no real improovments,
found one possible boostleak (EVAP), fixed, no real improovent.
Will continue look for boostleaks.


I searched and found some threads with similar problems (above 5500/6000 rpm no, or losing power) but only one wrote what's the problem was (boost leak).

Has anyone an idea?

Can a small boostleak cause this? Almost full boost, but low power?
On a boostleak test, to which position do you set the engine? OT? Must everything be complete tight? Or can the wastegate leak from the boost side into the dumptube side? Along the axle ... you know what i mean?!

I'm running out of ideas ...

TIA
Christian

PS: Sorry for my bad english, my mother language is german.

JDogg

sounds like vtec isnt enguaging.

doc

Hmm. Can't tell it. It's too loud in the car to hear it.
But good idea. I'll test the VTEC by hand, to be sure that it works.

Any other idea?

TIA,
Christian