I just bought a 63mm test pipe for my 2001 S2000 and i'm a bit curious of how much horsepower and torque is improved on an aftercooled Comptech supercharged F20C S2000 with factory exhaust and factory header....

4-5 horsepower maybe?

 

Probably ~20whp assuming its tuned on an AEM/Hondata

 

Lol not yet... Still on FPR

 

i'm thinking you'll get 20whp if you swap to a 70mm test pipe and exhaust. 8-10max with test pipe only

 

6-10whp

The stock 60mm exhaust system is pretty efficient for a SC, which is a bit surprising for some considering its the factory size, but its not a turbo either. The header is especially well designed, I still run a stock one myself, though I think there could be some marginal gains made at my boost level. A freer flowing 60mm cat back will give you another 8-10whp on top of the TP at moderate boost levels, so yes 20whp from a TP and cat back at high boost levels can be expected. At 5-7psi your not going to see quite as much gains in your exhaust system. I'd recommend keeping the stock header until you get high boost, it will support 400whp, after that its a bit of a bottle neck. But the 60mm exhaust does perform well for us. There is a point where it just makes more sense in cost vs power to run more boost, until you max out your flow, then spend money on the exhaust if you really want to take it to the next level. Your running an fpr with stock injectors, so unless your willing to dabble in water/meth, your going to be limited on fuel support whether you change to a higher flowing exhaust or more boost. The net result is the same. But boost is cheaper is the point I'm making.

 

I got tuned with stock header and a 63mm testpipe. made a tad bitover 400whp. Then got a plm header and testpipe which was a 70mm, and the power didn't change at all. Not even the tq. Mase brought up both maps and they were identical. But the car seems quicker tho. lol! Im sure more power could be made, but i wanted a conservative tune. And im happy with it.

 

Ugh, im really tempted to go test pipe. Especially since the cost of welding in a wideband bung into the stock header would pay for it. I'm a little concerned with the smell and also all the black soot on a white car.

Right now I'm in the process of putting on the kit with the ct FPR. It came with an Ultimate Racing intercooler kit and also the 3.8 pulley to bring me back to 6 psi on my ap2.

If I add the test pipe, does the FPR have enough range to bring my a/r to a decent level? I've heard of the test pipe leaning out tunes.

 

A little trick to keep your bumper clean...
Spray some Simple Green on the exhaust build up spot every 2-3 weeks (or whenever it becomes noticeable) when you wash the car. Let it sit for a minute , rub off with a wet microfiber towel & rinse the area thouroughly. The brown crap will come right off. I have done this a bunch of times & it never affected my paint. It even took off exhaust gunk that had been on there for +6 months .

 

Probably not the best example as dyno where done on different days but same dyno.

My mates car only mods were a testpipe, stock CTSC+AC 7spi and test pipe - 321BHP @ fly, 202 lb ft torque.

MY car, CTSC+AC 7psi, tracysports ts-02 header (jethot coated), Greddy Emange Ultimate, HFC and 5zigen 63mm singlepipe - 367BHP @ fly, 230 lb ft torque.

 

If you do indeed net 6psi, then yes you should have room to add enough fuel enrichment with the TP.