Downpipes

[Knight2040]

alright before i go and buy a test pipe, i was wondering if it was just worth it to get a stillin downpipe that eliminates the main cat and the front pre cat? do downpipes create noticiable gains in a near stock car? will i notice a diffrence? is it worth the 300+ bucks?? thanks guys

[Igovert500]

The downpipe is definantly worth replacing.
I suggest reading this:

http://johnmonnin.netfirms.com/Downpipe.html

it is a great comparison of all the aftermarket downpipes. But the stock is very restrictive and you can pick up quite noticeable gains if you replace it. Especially if paired with the removal/gutting of the 3 cats. I do suggest if you get the stillen dp that eliminates teh front precat, to either gut the rear precat or buy a rear precat eliminator, as you want the airflow to be equal between the 2. But removing all that unnecessary backpressure will really improve the performance of your turbos. I would recommend it quite early in the stages of modifications. Paired with a boost controller and open element intake you are looking at close to 400hp at 14.5psi
Hope that helps.

[Knight2040]

damn thanks for the link man, real informitive, u think i could really push close to 400hp with just the downpipe,open intake and 14.5 psi? do i need fuel mods to push 14.5 psi. wheres fuel cut agian? thanks

[thre3kgt811]

do u think the downpipe alone would show noticebale differences on a n/a car? possibly paired with an intake?

[Igovert500]

thre3kgt811...I don't know about an N/A car, but I would think it would be noticeable. Another guy just posted about the 3sx n/a downpipe on his car being a great mod and he seemed to like it alot.

Knight, as far as 14.5psi that is generally the excepted top psi you can push out of the stock fuel system safely. At 15psi you will get knock. Stock 91-93s run 9-10psi from the factory, and 94-99s run 11-12psi. As you can tell just from that fact, the stock boost gauge sucks and is highly inaccurate. So to reach 14.5psi, you need an accurate aftermarket boost gauge that will allow you to monitor the boost levels. Then a boost controller, either manual or electronic to boost to 14.5psi. Somewhere around 15psi you will start getting knock(pre-detonation) so even if your car seems fine, you could destroy your pistons and ruin your engine. So don't go higher than 14.5psi without upgrading the injectors and fuel pump.
As far as 400hp, if you have your car in good running order, ie, good plugs, wires and fuel filter. Then have an intake, gut your precats, a downpipe, and run 14.5psi I would think 400hp possible.