I just running the spring for now. 7psi sprint but im boost 8-9psi. i think its because of my 3indp an 3in exhaust. also when i turn up the boost will it still spike?

Thanks

turbonetics t3/t4 60 tim an tial 38mm wg.

 

What manifold and Turbo do you have?

 

Where do you have your vac line for the WG. comming off the intake mani or off the turbo. Also how big is the line. is there anything sharing that line as well?

 

herms fab log mani. i have the vac lines going directly to the IM. i do have a nasty exhaust leak from the mani to the turbo. could that be it?

 

up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DrivinVtec &raquo;</TD></TR><TR><TD CLASS="quote">herms fab log mani i have the vac lines going directly to the IM. i do have a nasty exhaust leak from the mani to the turbo. could that be it?</TD></TR></TABLE> there is a problem...and an exhaust leak will cause you not to boost like it should. 3" dp and exhaust will cause some boost creap depending on the turbo on top of that log manifold.

 

i would think if i raised the boost 15-20 psi it should stop. yes?

 

it might, just depends on your setup. list your turbo and stuff and we will all have a bette idea of what your workng against

 

Hersm fab log mani
3in dp
3in exhaust with 3in resgintor
38mm tial wg
turbonetecs t3/t4 60trim .63ar

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DrivinVtec &raquo;</TD></TR><TR><TD CLASS="quote">herms fab log mani. i have the vac lines going directly to the IM. i do have a nasty exhaust leak from the mani to the turbo. could that be it?</TD></TR></TABLE>

there is your problem. run that vacuum line to a source at the turbo or the IC piping coming off the turbo. When i had the vacuum line from the wastegate run to the IM i was getting serious boost creep. On my 7psi spring it would go to 8 then 9 until i shifted to next gear. I couldn't even do 4th gear pulls that's how bad it was. Switching the line to a better source solved everything. I hold a rock steady 7.5 psi or so on my tial 38mm wastegate.

 

Where are you reading the 8-9 psi from? If you are reading it from a mechanical boost gauge then it means very little. My car has a 8 lb spring and my gauge reads 10 but the datalogs show 8 so it is just that the gauge is off a bit. Same is probably true in your case also.

 

I have the vac line from the wg going to the turbo it self. the way u have it

it could be the gauge . it is mechanical

 

get a bigger wastegate

 

38mm big enough for 400whp

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DrivinVtec &raquo;</TD></TR><TR><TD CLASS="quote">38mm big enough for 400whp</TD></TR></TABLE>

im making about 415 with one. im using a hallman manual boost controller and it hits 17 psi and holds steady to 8700 rpm rev limit

 

ya well u hardly have problems with boost creep when ur runnin ur turbo on a high psi setting so u cant say a 38mm is ok for 400hp @17... the 2 dont relate.. how many ppl do u hear sayin im runnin a 20psi spring and im creeping to 23psi??

since ur not running ur turbo to its max psi or even close to it, and ur having boost spikes, u should swap for a bigger wastegate that can channel that excess exhaust gas away from the turbine at a higher rate..

the bigger the wastegate the more gas it will channel away from the turbo.. if u wanna run highboost then a smaller wastegate is fine cuz u want all the boost u can get..

 

People automatically start blaming exhausts and manifolds and springs, when the most obvious solution is just that mechanical boost gauges are only accurate to +/- 20%. Datalog your MAP sensor and I'll bet it is right on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 187Chor &raquo;</TD></TR><TR><TD CLASS="quote">ya well u hardly have problems with boost creep when ur runnin ur turbo on a high psi setting so u cant say a 38mm is ok for 400hp @17... the 2 dont relate.. how many ppl do u hear sayin im runnin a 20psi spring and im creeping to 23psi??

since ur not running ur turbo to its max psi or even close to it, and ur having boost spikes, u should swap for a bigger wastegate that can channel that excess exhaust gas away from the turbine at a higher rate..

the bigger the wastegate the more gas it will channel away from the turbo.. if u wanna run highboost then a smaller wastegate is fine cuz u want all the boost u can get..
</TD></TR></TABLE>

exactly what i was thinking but i didn't feel like taking the time to say.