Loss Of Power After 5000rpm

[OVADRV]

Car: R33 gtst 1994

MODS: apexpi pfc

nismo fuel reg

slide performance highflow turbo stage 3

hiflo exhaust 3inch-split dump

bosch fuel pump internal

z32 afm

garret wastegate acuator new

15 psi

tuned

My problem is when i reach around 5-6000 rpm it looses power,and boost reading drops excessivley as if somthing has blocked the air intake.

has anybody had this problem?i have checked all pipes and fittings?

[Simmo1985]

I've got this exact same problem. Sometimes I get a loud whistling type sound in the higher RPMs. I've only got some basic bolt on mods, FMIC, split front/dump pipe, high flow cat, manual b/c at 10psi. Mine drops off to next to no boost past 5000rpm. My friends Dad had a look at it tonight, he's a nissan mechanic. We weren't able to solve the problem unfortunately. Got us pretty stumped.

[R31Nismoid]

Sounds like an actuator problem to me.

Sure its installed correctly?

[Cubes]

Ovadrv,

15psi through a highflow.

Its possible the standard turbo to afm rubber pipe is sucking closed slightly causing the boost drop.

[OVADRV]

cubes i have that silicon inlet hose thats not sposed to suck close.i will put my standard inlet hose back on tomorrow and see what happens.

[Dose Pipe Sutututu]

those silicon ones collapse as well...I had re enforce mine with a stainless steel offcut

[OVADRV]

your joking john isnt that silicon hose sposed to eliminate that problem (sucking close) if so its a complete waste of money,im gonna put my stock inlet pipe on and reinforce it,did the problem go away for you onced rienforced??

[Dose Pipe Sutututu]

I regret buying it, wasted $150... was pretty worthless! Re-enforced it all sweet, I don't get a boost drop anymore!

if you squeeze it you'll notice its actually softer than the stock pipe!

[OVADRV]

yes it is softer

[R338OY]

Sounds like an actuator problem to me.

Sure its installed correctly?

How can you check the actuator? I have a similar problem (gauge reading falls).

[r33cruiser]

hey mate. would u have the afr readout of it, on a dyno. if possible?

[OVADRV]

im gonna try this out on the weekend, i have no time at the moment (for once search button has worked)http://www.skylinesaustralia.com/forums/t173019.html&hl=inlet+pipe

[OVADRV]

ok people i did that mod with the pipe in the middle of the standard intake pipe,went for a drive and it works.no more power loss,me very happy.

[Ionos]

If your intake pipe is sucking closed, that suggests to me that your air filter is too restrictive. Take the air filter off and go for a quick drive, see if it's still an issue, but avoid any dirt roads!

Edited November 19, 2007 by Ionos

[OVADRV]

no,its not the air filter,its a k&n filter never had this issuse until i raised the the psi,it all fix anyway,good point anyway.