Wastegates: dump to atmosphere or route back to DP?
Jim
I'm not understanding your results ... Changing the wastegate routing shouldn't have any effect on spool. With an EBC, the gate shouldn't even open till you hit full boost anyway (or very near full boost), so there shouldn't be a change in spool time. Without a EBC, the gate will begin to open earlier, but I still can't see spool being quicker ... If you think about it, spool would probably be slightly worse if you make the wastegate discharge more efficient.
Did you redo the downpipe at the same time? Making a better downpipe would positively effect spool.
Phil
It helps in the spooling and boost control.
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It helps in the spooling and boost control.
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Less back pressure and no reversion could help.
He also mentioned that you should try and make sure
that the exhaust from the wastegate dump tubes does not get into the intake.
Merry Christmas =)
Maybe not a huge difference but at that level you will take what you can get.
My street cars all have the gate going back into the DP BTW... =)
Festive Kwanzaa and Happy Hanukkah as well
but explain how dumping the wastegate will make the boost come on faster when the wastegate really has nothing to do with how the turbo spools. THat is all in the motor/turbo sizing.
The wastegate does not open untill a set boost point is reached, and untill that boost is reached, where the wastegate is routed to has no effect on anything. So the turbo is spooled and to a set presure (set by the spring in the wastegate or a boost controller), THEN the wastegate opens.
Understand where im coming from now? The idea of dumping the wastegate is to eliminate boost creep and basicly let everything breath better AFTER the wastegate has opened to release some pressure. Turbo spool happens before the wastegate even comes into play... so how would its piping effect spool?
It won't (effect spool)... but im still a "newb" so if you know something im more than willing to learn.
Nothing against you at all, I'm just extremely curious as to why it helps spool, and so far I have yet to read anything in this post that explains this. Forget peak power potential or boost control - those make sense when talking about the WG. But spool? Think about the extreme - fastest spool would be achieved by completely blocking off the wastegate.

I'm not understanding your results ... Changing the wastegate routing shouldn't have any effect on spool. With an EBC, the gate shouldn't even open till you hit full boost anyway (or very near full boost), so there shouldn't be a change in spool time. Without a EBC, the gate will begin to open earlier, but I still can't see spool being quicker ... If you think about it, spool would probably be slightly worse if you make the wastegate discharge more efficient.
Did you redo the downpipe at the same time? Making a better downpipe would positively effect spool.
Nothing against you at all, I'm just extremely curious as to why it helps spool, and so far I have yet to read anything in this post that explains this. Forget peak power potential or boost control - those make sense when talking about the WG. But spool? Think about the extreme - fastest spool would be achieved by completely blocking off the wastegate.
NP,
I will try and call to you the correct information next week.
My wife is having contractions though, so I can not make any promisses.

We ran a wastegate totally closed at Orlando this year. It was not the greatest idea, It pegged that 3.5 bar map sensor in under 2 seconds. This was wish a 272ci motor and GT47 88MM. The closed gate or will spool the fastest, my point is the a gate vented out side of the down pipe will spool faster than one in.
its not rocket science.. simple... the wategate does not affect spool.. dumped or not... (unless the wastegate is leaking exhaust by before it opens)
I mean no disrespect, but it is pure physics and law.
Your car got faster because of YOU CHANGED THE TURBO HOUSING... well DUH!!! YOU CHANGED A MAJOR PART IN THE TURBO, therefore effecting spool.
You changed soo many aspects of what is going on there that your results will not be like if I were to dump my wastegate apposed to having it merge into the DP.
I will try and call to you the correct information next week.
My wife is having contractions though, so I can not make any promisses.

We ran a wastegate totally closed at Orlando this year. It was not the greatest idea, It pegged that 3.5 bar map sensor in under 2 seconds. This was wish a 272ci motor and GT47 88MM. The closed gate or will spool the fastest, my point is the a gate vented out side of the down pipe will spool faster than one in.
Im not here to make enemys guys, but you seriously just must not see this.. its simple...
Turbo spool happens before the wastegate even comes into play!!!! so how would its piping effect spool?
THe turbo spools, makes boost, THEN the wastegate opens at a set pressure. At that point, and only AFTER the turbo has spooled and is MAKING BOOST will the wastegate routing have an effect on anything
Last edited by Dragframe; Dec 25, 2006 at 01:03 PM.






