External Wastegate

[kojiki88]

Hey guys and gals. I'm having an issue with boost creep. On my old setup which consisted of a Stock Blacktop SR20DET, S15 GT28RS, Greddy FMIC, Nismo FPR with and a Tial MVS EWG 38MM set at 11psi. I never had any Boost Creep in any gear.

I decided I wanted more power so I went ahead and got HKS 740cc injectors, Z32 Maf, Toda 264 cams, Apex HG, GoldenEagle Headstuds (B16), and a Small red spring to even out to 17psi Got it tuned through RS Enthalpy. Went out for a drive 1st, 2nd and 3rd gear hit 16psi or 17 ( not sure since I want to maintain focus on the road) But when I drop the gear from 5th to 4th boost hits close to 20psi then drops down to 17psi. I've checked all Vacuum hoses and everything seems fine. I don't know whats going on now to have boost creep. My wastegate was installed on the stock exhaust manifold. Any input would be appreciated. Thanks.

This is where the wastegate is located.
http://i289.photobucket.com/albums/ll219/driftereighty/100_9353.jpg

[rcdad123]

wastegate dump valve is too small. you need a bigger wastegate.

[kojiki88]

thanks for the reply but I don't think its the wastegate. My brother has the same waste gate running the gt2871r at 15psi and he has no boost creep at all. But what do I know if im the one asking for advice. :)

[pandaroo]

^^yah but his turbo is bigger than yours. smaller turbo=more dumping to stay at the same pressure as a bigger turbo.

[abunai the drifter]

check to see if you boost line is on and if your vacuum to the wast gate are tight or you could have a an 20lb spring

[mattsil80wis]

do you have the middle nipple of the WG going to the hotpipe?

like this
http://www.codyace.com/albums/album281/matt032010_20.sized.jpg

are you running a boost controller?

[kojiki88]

check to see if you boost line is on and if your vacuum to the wast gate are tight or you could have a an 20lb spring The line to the wastegate is on tight I am going to add a ziptie to be safe. I tried moving it and pulled it and wouldn't budge. It can't be the spring since the other gears don't pass the boost its suppose to be at.

do you have the middle nipple of the WG going to the hotpipe?

like this
http://www.codyace.com/albums/album281/matt032010_20.sized.jpg

are you running a boost controller?

The line that comes off the middle nipple is T'd off to the BOV and then goes to the Intake Manifold.

[fliprayzin240sx]

You got boost creep because of the wastegate placement. Its not exactly placed to help with the exhaust flow out of it.

[kojiki88]

You got boost creep because of the wastegate placement. Its not exactly placed to help with the exhaust flow out of it.

I guess getting a tubular manifold with a well routed external wastegate tube help the problem.

[mattsil80wis]

You got boost creep because of the wastegate placement. Its not exactly placed to help with the exhaust flow out of it.

I guess getting a tubular manifold with a well routed external wastegate tube help the problem.

im running a stock mani without any problems on boost creep

i had my mani done by cody ace

i doubt that is the problem

[mattsil80wis]

The line to the wastegate is on tight I am going to add a ziptie to be safe. I tried moving it and pulled it and wouldn't budge. It can't be the spring since the other gears don't pass the boost its suppose to be at.



The line that comes off the middle nipple is T'd off to the BOV and then goes to the Intake Manifold.

the BOV should go to the Intake Manifold and the middle nipple should go to the hotpipe

[kojiki88]

the BOV should go to the Intake Manifold and the middle nipple should go to the hotpipe
Ahh, is that how it's suppose to be? I'm gonna need to weld a nipple on the hot pipe then. The top nipple is not connected to anything since I'm not running a boost controller, Is that fine?

[kojiki88]

Ok here's an update.

So this past Saturday I went out for a drive got on the highway and decided to try out stepping on the car again in 4th gear. Watching the boost gauge, it hit 20psi stayed for a second or two and dropped down to what it looks like 17psi. Ok.. Hmm I decided to drop the speed and put third in. I was about 5k rpm and floored it,(same issue as 4th gear) It hit 20psi stayed for a second or two and dropped down to 17lbs. At first I thought maybe I did have 20psi springs but once the psi dropped down to 17psi it's not possible. Confused. :s