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2.8T any hard evidence that a DP increases performance?

3K views 32 replies 11 participants last post by  kanundrum 
#1 ·
Any before and after dynos of a DP install everything else being equal?
 
#2 ·
I;d be curious to see this too. You likely wouldn't see hard number increases, but an actual dyno graph would show the benefit.

All a DP does is decrease the level of backpressure that hinders the turbo's spooling ability. It likely wouldn't produce higher numbers by itself, but you should be able to see the turbo reach its programmed boost output at a slightly lower RPM than stock.

That said...

The 2.8T turbo is pretty small, so the spool benefit from a DP might be negligible.
 
#4 ·
On my Toyota Supra, i have gain 23 whp just with a downpipe.
Also, the downpipe help A LOT in decreasing the temperature under the hood. Before the downpipe, my turbo was glow red, after nothing.
I have had over 20 turbo car and a free downpipe have always give me good result. In the next week, i will make 1 for my Aero.
 
#12 ·
Those are really solid numbers, especially from a Dyno Dynamics test.

Were both SAE corrected, or uncorrected?

(Trying to see whether a ~5 percent gain was affected by ambient temps....)
 
#28 ·
If underhood temps are dropping as much as folks claim, then that's a likely sign that the stock setup (turbine wheel, exhaust housing, DP) is severely undersized.
 
#30 ·
Anybody see any gains from just from just cutting out the second cat and using a straight pipe? Maptun likes to promote their downpipe (midpipe) as greatly reducing back pressure. Any truth to this? Its a pretty easy mod especially if it yeilds some addtional HP.
 
#31 ·
getting my mid pipe chopped next weekend and on the dyno end of this month i can have raw numbers then. I found someone localy for my downpipe but i have a question people are spacing out the o2 sensor on the cat on the DP so it's only catching a sniff and not causing a CEL. Anyone have info on that spacing or photo? Trying to bring specs to this guy because he is a hobbyist and is down for working on it just never fabbed one on the lp9.
 
#32 ·
I've got 3" turbo back exhaust and I can definitely tell the car gained a few ponies. And especially when heat wrapped it did decrease temps in the engine bay.. but if you're looking to decrease engine bay temps you could always ceramic coat the intake mani, heat wrap the downpipe if you have an after market one, and remove the plumbing from the front end and get rid of all of those engine covers. I did all that with mine and a fmic, aside from the ceramic coating and my radiator support which used to be extremely hot after running the engine hard is ice cold now pretty surprising but with increased ventilation it really helps.
 
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