question about rearmount
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11 Second Truck Club
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From: Missouri
question about rearmount I have a rearmount setup on my S10 Blazer. The kit started life as a STS kit for a 2002 truck but after all the modification there isn't much STS left lol.
Anyways, it seems to be "choked" and I have been theorizing that maybe my tailpipe is the restricition (the tailpipe is basically the downpipe in a rearmount) My turbo is a 74mm and the tailpipe is 3 inch out of the turbo, over the axle and out the back. Is there any reason why I couldn't pull the tailpipe off at the track and just let the exhaust dump straight out of the turbo? Would it be better to do a short "turndown" ?
Anyways, it seems to be "choked" and I have been theorizing that maybe my tailpipe is the restricition (the tailpipe is basically the downpipe in a rearmount) My turbo is a 74mm and the tailpipe is 3 inch out of the turbo, over the axle and out the back. Is there any reason why I couldn't pull the tailpipe off at the track and just let the exhaust dump straight out of the turbo? Would it be better to do a short "turndown" ?
I have a rearmount and I have a 3" flowmaster from turbo to bumper. When I dropped the muffler the boost went from a maximum of ~12 psi to 19.
Restrictions after turbo can make a huge difference on spool and upper limit. I never ran mine without a pipe and also wondered.
Restrictions after turbo can make a huge difference on spool and upper limit. I never ran mine without a pipe and also wondered.
Do a turn down. You don't want to melt anything under there. If that doesn't do what you want bump up your AR to .1.0-1.25(whatever's available for your application). You have an auto car, so you can run a larger housing and get away with it. What turbo is it exactly? Your air filter can also hold you back. Are you running an Outerwear over the filter at all? That can hurt as well.
Thread Starter
11 Second Truck Club
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From: Missouri
Do a turn down. You don't want to melt anything under there. If that doesn't do what you want bump up your AR to .1.0-1.25(whatever's available for your application). You have an auto car, so you can run a larger housing and get away with it. What turbo is it exactly? Your air filter can also hold you back. Are you running an Outerwear over the filter at all? That can hurt as well.
The turbo is from Precision, dont have the specifics in front of me but I know its a 74 mm and they spec'ed it out based on my combination. The outerwear is long gone, that was one of the first things I ever read about the STS kit was to lose the filter cover ASAP. Also I forgot to mention that I am not running a muffler.
I am hoping to have some time to work on it the Friday and if all goes well maybe take it to the track Fri evening.
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Joined: Jul 2010
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From: jacksonville NC
the length of your tailpipes could have alot to do with it.you dont want long exhaust pipes coming out after the turbo maybe 2 or 3 feet max.if you take to much out you with get a flat spot on the low end but it makes up for it on top.i would put about 1.5 to 2 feet pipe coming out of the turbo with a turn down.sounds like you have to much back pressure.i cut mine to short and lost to much low end you need to test out different lengths after the turbo to get what u want.
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11 Second Truck Club
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From: Missouri
I checked the tag today-the numbers on my turbo say its a PTB 650-1825 and it also says 74 GTSHP if that means anything to anyone. I just looked at Precisions website and it says its good to 1050 hp.
I think i have the things on hand to make a turndown so if all goes well I will work on it some this Friday.
I think i have the things on hand to make a turndown so if all goes well I will work on it some this Friday.
