so i finially got a chance to drop my car off to have some custom exhaust work done, and i got a baseline dyno before and one after to see my gains. this was at altered atmosphere on an in-ground dynojet.

2005 scion tc with supercharger with stock pulley, weapon-r jet hot coated 4-2-1 header and s-pipe, stock mid-pipe, trd axelback exhaust, and zpi crank pulley, made 209 whp, and 183 lb-ft torque!

i was quite surprised because i was expecting this to be somewhere around 190 to 200 whp, comparing my tc to kanundrums, who dyno'ed 190 whp with my set-up, minus the header, s-pipe, and crank pulley. but i know that was on p-tuning dyno dynamics which they say is pretty strict and reads pretty low.

so now, after having custom 3 inch uncatted, exhaust with nothing but a muffler on the end, i was hoping to see a similar 15 whp gain that kanundrum did when he put on p-tunings exhaust, but shockingly...i only made another 3 whp!

so ...2005 scion tc with supercharger with stock pulley, weapon-r jet hot coated 4-2-1 header and s-pipe, 3 inch uncatted and unresonated exhaust and zpi crank pulley, made 214 whp and 182 lb-ft torque!

so to me it seems that if you already have a header on a supercharged tc, that will get you similar results to having 3 inch exhaust since the primary catalytic convertor has been deleted which is a large source of backpressure in the exhaust system. after that, you don't have much more to do, BUT if you want to be able to pass a smog test with your tc, then 3 inch exhaust is a good idea because you get a gain similar to that of a header, but you still have a catalytic convertor cleaning up your exhaust...

anyway, heres my dyno sheet:

 

Good work young one!

 

awesome

 

sweet!

 

Grrrrrrrrrrrrrrrrrreeaat.

 

Drax where about are you in Gburg? My roommate in school and a bunch of my friends live near Rio, if you know what that is. I'm down that way probly once a month...

Just curious

 

seems like you lost a LIL bit of Torque there.

nothing a 9,5or 10,5 PSI pulley can't resolve

 

i live out in laytonsville, and i work (well practically run) the mamma lucia's in olney. this shop is really convieneint, only 6 miles from my house.

 

I think you'll see better gains if you up the PSI.

I had the Megan header, Invidia s-pipe, 2.5" hi-flow cat, Vibrant ultra-quiet resonator, and the Magnaflow cat-back for exhaust work. I also had 9.5psi pulley, and lightened crank, wp, and alternator pulleys which got me about 203whp on the dyno-dynamics.

Replacing the the exhaust starting with the s-pipe all the way back with a 3" exhaust pushed me up to 217whp on the same dyno-dynamics, and a noticeable gain throughout the entire RPM range.

The sound caused by the Megan header was unbearable, so I went back to a stock header. Haven't dyno'ed it since swapping the header, but hopefully will find out soon when I go with meth injection and engine management.

congrats on the numbers though.

 

thanks, this tuesday i'll go back, and get the exhaust cat'ed and quieted down with a resonator, and then i'll swap on the 9.5 psi pulley and see what it will put down.

 

not apples to apples.
header w/stock exhaust back does not equal stock header with 3" back

the bulk of the blockage, especially with the s/c is nearest to the engine, not the tailpipe. if you went back to the stock header and swapped for the 3" back you would lose the hp. also, i am not surprise you only gained 3hp on a midpipe back. anything more is really a pipe dream..hah! i made a pun.

dyno proven...similar setup to you...weapon r header got me 21 whp gain (on a dyno dynamics) with the s/c and a 9.5 pulley. megan mid did nothing but make it louder, thats why i sold it.[/b]

 

well, i think my comparison is very similar, if you click the link in kanundrum's signature about his 3 inch exhaust set up, you will see what i am talking about.

kanundrum dyno'ed 190 whp on a p-tuning's dyno dynamics meter with his stock supercharger, stock header and mid-pipe and trd exhaust. with just the s-pipe back 3 inch exhaust that they put on, he made 205 whp, a gain of 15.

but with my stock supercharger, weapon-r header and s-pipe, and stock mid-pipe, and trd exhaust, and a crank pulley, i baselined 209 whp on an inground dyno jet. now i know that different dyno's give different numbers and such, but seeing as how i'm not going to p-tuning for a dyno pull, it is what we have to compare. so with just a header, i had a pull that was very comparable to what kanundrum did with 3 inch exhaust, and a stock header.

anyway, this tuesday will come another dyno, this time with 9.5 psi, and a cat and resonator welded in place.

also, i'm curious why my afr's start out richer than then they did before...kinda strange...

 

just saying...
i find an increase of 15hp on an exhaust from the spipe back dubious. there is some error, or something else is afoot.

your results of 3hp are much more likely.

 

woudnt a 4-1 header result in more power than a 4-2-1? seems to make sense to me but i dont know.

 

it seems to be a trade-off between designs, 4-2-1 headers help provide more torque across the powerband while 4-1 have more high end power. and since i spend most of my driving in the lower rpms, i appreciate having that extra power.

and the weapon-r header is such a great looking design, so i think it has to be the most effecient one out there for the tc.

but a 4-2-1 header is alot harder to make than a 4-1 header, so i don't think they would go throught the trouble of making this kind of design if there was a certain benefit to it.

 

good numbers,not many goes in the 200s

 

Not bad keep in mind your dyno that you say only has 3whp diffrence was slighty hotter that day and little more humidity.

 

well, looking at the numbers, 3 whp sounds like it is in the dyno's margin of error LOL!

 

You should've ran a baseline during the same day before the exhaust was put on. That would've been a better comparison.

 

well, i dropped it off on a tuesday, i was also having my aem boost, wideband and oil pressure gauges installed.

they were supposed to start on it tuesday, but their mandrel pipe bender had to be switched over from 2.5" piping to 3" piping, and they said they were pre bending some 2.5" pipes that they needed before they switched the jig over to 3" piping. then when they started to do my exhaust, they found that i had at some point before i brought it in, had bottemed out my car, and bent my header/s-pipe so the s-pipe was actually touching my axle, so they had to take that off, heat it up and bend it back to its proper shape. and while they did that, they put the o2 bung on there for the o2 sensor, and tap the oil pan for the oil pressure sensor and then put some holes in the dash for the center mount gauge pod, which i am pleased, it came out super clean!

so it wasn't just exhaust fabrication and installation, there were a few other things to be done. i can't wait for tomorrow though, putting a cat and a resonator and a 9.5 psi pulley because my car is loud and smelly!