With only a high press fuel pump, adj fp reg, chip, cone air cleaner, and hi-flo cat, what kind of response will I "feel" when adding a bigger downpipe? And will porting the exhaust elbow on the turbo yield major or minor gains as well? Being on a limited budget, I'm trying to get the most bang for my buck. Thanks.
Downpipe gains
- Thread starter 85zoom
- Start date
With as horrible as the stock DP is I would say it might actually give you .5 with a tuned car (pump, high boost, chip, filter). Go ahead and port the elbow while you're in there. The two will complement each other. While you're at it gut the catalytic convertor or get a test pipe (some of the aftermarket DPs come with them). You will also notice that the turbo will spool faster.
I have a nicely ported elbow but I made one small cut with a hack saw so it would have to be welded or I would give it away.
I have a nicely ported elbow but I made one small cut with a hack saw so it would have to be welded or I would give it away.
REDS HOT AIR
Buick Tweaker
- Joined
- May 24, 2001
i agree when mine was hotair and i went to the atr d/p it was a big spoolup difference over stock.
i ported the elbo and also i ported the inlet of the turbo to line every thing up an give it a nice funnel down to the wheel instead of taking steps on its way in.
while your at it port the inlet to the ext housing to match the lil adapter that seals the uppipe to it.
i ported the elbo and also i ported the inlet of the turbo to line every thing up an give it a nice funnel down to the wheel instead of taking steps on its way in.
while your at it port the inlet to the ext housing to match the lil adapter that seals the uppipe to it.
I
Iamdreaver
Guest
what is a test pipe?
Basically you are removing the catalytic convertor and putting a (test)pipe in it's place, or if you want to be sneaky, gut the honeycombs in the cat, and weld a piece of pipe thru the cat. I'm not sure of the technical details of it, but just removing the honeycombs and retaining the bigger open area in the cat seems to be undesirable. So, the next time you're driving around town and the catalytic convertor police patrol pull you over for not having a cat on your exhaust, you simply state you have a testpipe on instead, and all will be OK!
The sad thing is here in CA they will look for a cat sometimes. Not very often but if you get an officer that's just looking to bust you, they will look and your car gets taken away if you don't have one. That's why I've always gone with the more undesirable gutting of the cat. When I was leaving the streetraces one time I got pulled over and was asked to pop my hood to look for "illegal" stuff and nitrous. I had to argue for 30 minutes that the turbo came on the car from the factory and it was legal. Some states really suck.
Wacth out for Boost creep after replacing your down pipe. On my engine , I had to enlarge the wastegate hole to a little under the size of the puck. I had boost creep fter I replaced my with a 2.5" downpipe that Eric Rankin made for me. My car is carbed , but I belive ours trubos are in the same place on the engine.
Just my two cents , may save you a head gasket.
Just my two cents , may save you a head gasket.
I
Iamdreaver
Guest
next dumb question, what is boost creep?
