HELP! Massive boost creep Greddy KA kit. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Colorado S14 · 10-05-2004, 12:08 AM

I have a Greddy turbo kit on my car and recently installed a SR20 3" DP and a Profec B spec II BC. I now have a serious boost creep issue. My car will rev and I hit 6 psi at 3000 rpm. The car then bogs and feels like it has hit a wall. But then at like 4500 it will take off again but the boost will keep creeping all the way to a scary 13 psi.

I dynoed it today and this shows up dramatically on the dyno chart I loose 25 hp here between 3500 and 4500 rpms. My a/f ratio is a solid 12:1 across the board. I set my base timing back to 20* BTDC and am pulling 8* using the Emanage. This creep happens with and without the Profec B hooked up. What is it? I am going crazy!

I am thinking that the design of the Greddy is a bigger part of the reason for the low numbers people are getting than I used to. I used to think that it cannot be that different from the other kits and the low numbers are due to the terrible settings that GReddy sends the Emanage out with.

This picture does not show it completely but you get the idea, look at how they blocked the wastegate exit and are forcing its flow to go into the exhaust stream at a 90* angle and use the same outlet as the turbine.

I have the creep issues with the wastegate hooked up to the hot pipe and when it is hooked up to manifold vacuum, without the boost controller.

Another thing, when it over boosts to like 13.2 psi it does not feel that much stronger then when I was stable at about 6 psi. In fact on the dyno with the boost creeping to 12 psi, I only put down an actual 195 hp at 5500ft of altitude!

devonkyle77 · 10-05-2004, 12:15 AM

smaller dp?

CatchMyDrift03 · 10-13-2004, 08:45 PM

yes a smaller dp might just be it.. the greddy turbo kits are designed for the best street applications for a low rpm spool up and it will remain throughout the entire powerband. which you probaly already know. of course though a 3" dp is excellent when running a large turbo for lesser lag. but maybe on the greddy a smaller dp might just be your best bet. unless you turn up the boost..
BOOST THE SH*T OUT OF IT!!!

10-05-2004, 12:08 AM	#1
Colorado S14 Zilvia Member Join Date: Aug 2002 Location: Denver, CO Age: 41 Posts: 192 Trader Rating: (0) Feedback Score: 0 reviews	HELP! Massive boost creep Greddy KA kit. I have a Greddy turbo kit on my car and recently installed a SR20 3" DP and a Profec B spec II BC. I now have a serious boost creep issue. My car will rev and I hit 6 psi at 3000 rpm. The car then bogs and feels like it has hit a wall. But then at like 4500 it will take off again but the boost will keep creeping all the way to a scary 13 psi. I dynoed it today and this shows up dramatically on the dyno chart I loose 25 hp here between 3500 and 4500 rpms. My a/f ratio is a solid 12:1 across the board. I set my base timing back to 20* BTDC and am pulling 8* using the Emanage. This creep happens with and without the Profec B hooked up. What is it? I am going crazy! I am thinking that the design of the Greddy is a bigger part of the reason for the low numbers people are getting than I used to. I used to think that it cannot be that different from the other kits and the low numbers are due to the terrible settings that GReddy sends the Emanage out with. This picture does not show it completely but you get the idea, look at how they blocked the wastegate exit and are forcing its flow to go into the exhaust stream at a 90* angle and use the same outlet as the turbine. I have the creep issues with the wastegate hooked up to the hot pipe and when it is hooked up to manifold vacuum, without the boost controller. Another thing, when it over boosts to like 13.2 psi it does not feel that much stronger then when I was stable at about 6 psi. In fact on the dyno with the boost creeping to 12 psi, I only put down an actual 195 hp at 5500ft of altitude!

10-05-2004, 12:15 AM	#2
devonkyle77 Post Whore! Join Date: Sep 2003 Location: md Age: 41 Posts: 3,091 Trader Rating: (3) Rides Gallery: devonkyle77 Feedback Score: 3 reviews	smaller dp? __________________ WTB-NARDI wheel & NRG 2.8 QR

10-13-2004, 08:45 PM	#3
CatchMyDrift03 Join Date: Feb 2003 Location: america Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	yes a smaller dp might just be it.. the greddy turbo kits are designed for the best street applications for a low rpm spool up and it will remain throughout the entire powerband. which you probaly already know. of course though a 3" dp is excellent when running a large turbo for lesser lag. but maybe on the greddy a smaller dp might just be your best bet. unless you turn up the boost.. BOOST THE SH*T OUT OF IT!!!