Boost Creep Still!!
#1
Boost Creep Still!!
I was having some issues with the Boost creeping on my TC as you guys might remember. I also had a boost leak somewhere which I fixed, now the boost goes even higher and is sometimes erratic. I am going to change the back housing of the turbo to a larger 5.8 it currently has a 5.0 housing. This will also give me some more overall whp with a little more lag. The good thing is that my barely has any lag at all the car starts to boost at about 3500rpm with a T4 ball bearing turbo. Do you guys think this will fix the problem? I really don’t think it is the waste gate.
#3
Originally Posted by ERIC-TC
Give us some details on your wastegate? Have you done a leak-down test on your vaccum lines? Do you recirculate the waste gate?
#7
It might be related to the 3" exhaust. I had my boost dialed in 9.5 with a manual boost controler when I decided to cut out my cat. For fun I drove it for 2 days with no exhaust comming off a 2 1/2" down pipe, but I had MAJOR boost creep. Up to 13 psi and would of went higher if I kept pushing it. When I buttoned the exhaust back up it ran a solid 9.5 psi.
I've been told that 3" exhaust are to big for the low boost applications 99% of us are running. One of the major issues being boost creep do to the lack of back pressure.
I've been told that 3" exhaust are to big for the low boost applications 99% of us are running. One of the major issues being boost creep do to the lack of back pressure.
#10
[quote="peteyd"]yea may want to do 2.5" all the way. ive herd 3" doesnt have enough back pressure for the tC.[/quote
That is a myth...Forced induction does not need back pressure like a N/A car.
That is a myth...Forced induction does not need back pressure like a N/A car.
#12
Originally Posted by cdubber9
Then what made me have boost creep when I went no exhaust? Then it was gone as soon as I hooked it back up. The only thing that changed was the back pressure.
#13
Originally Posted by Rasta
Originally Posted by cdubber9
Then what made me have boost creep when I went no exhaust? Then it was gone as soon as I hooked it back up. The only thing that changed was the back pressure.
What you need is an adequate wastegate or to run more boost. Only other option is to create backpressure which will slow down the turbo so your wastegate can keep up. Try adding a high flow cat!
#14
Originally Posted by tcengel
Originally Posted by Rasta
Originally Posted by cdubber9
Then what made me have boost creep when I went no exhaust? Then it was gone as soon as I hooked it back up. The only thing that changed was the back pressure.
What you need is an adequate wastegate or to run more boost. Only other option is to create backpressure which will slow down the turbo so your wastegate can keep up. Try adding a high flow cat!
#17
Originally Posted by Rasta
Originally Posted by tcengel
Originally Posted by Rasta
Originally Posted by cdubber9
Then what made me have boost creep when I went no exhaust? Then it was gone as soon as I hooked it back up. The only thing that changed was the back pressure.
What you need is an adequate wastegate or to run more boost. Only other option is to create backpressure which will slow down the turbo so your wastegate can keep up. Try adding a high flow cat!
Sounds like you do not want to change the wastegate since this is your second post about it. So, go have a cat welded into your exhaust. Problem fixed......
#19
When you run a bigger turbo at low boost that is when a bigger waste gate is needed. You can run a 38mm waste gate on the biggest of turbos at really high pressure's (or should I say really high flow) but then you try and control a large turbo/efficient turbo at low boost it will tend to creep. This is why DSM's get boost creep with 3 in down pipes. The turbo becomes more efficient. If you had a properly sized turbo for the power you are trying to make then you could live with a properly placed small waste gate.
#20
Originally Posted by OuterHeaven
When you run a bigger turbo at low boost that is when a bigger waste gate is needed. You can run a 38mm waste gate on the biggest of turbos at really high pressure's (or should I say really high flow) but then you try and control a large turbo/efficient turbo at low boost it will tend to creep. This is why DSM's get boost creep with 3 in down pipes. The turbo becomes more efficient. If you had a properly sized turbo for the power you are trying to make then you could live with a properly placed small waste gate.