In my quest to shave some more weight from my car and hit very low 10's maybe high 9's i am asking if it is beneficial to have an exhaust on a car, or if an open downpipe whether it be thru the hood, or exit from just under the car would in any way help the top end ; as well as it's weight benefits.

i have a buschur exhaust for the street

with exhaust removal i am suspecting my car would be around 2750-2800lbs with no driver


i was also thinking of switching to GSC S3 Cams. not sure if they would work well with my setup without changing out my whole valvtrain. i will only be revving to about 8400-8500 max

last year i was trapping 127 low 11's on 93 oct and 25psi on a standard 35r with about 400lbs more into the car on street tires with 1.8 60' . my best 60' was 1.6 on these tires so i have since switched to hoosier DR's



here's a run down of my setup as far as things that "matter" on the motor side
stock head ports. stock bottom end

STM Standard placement vband manifold
HTA86 w/ tial .82 housing
aem v1
-CompCams 272's
BC Springs & retainers
okada Plasma Coils,
Buschur Deluxe race Front mount.
2.5" ICP
tial q/tial 44
Buschur 3" Turbo Back Exhuast
Magnus V5
E85


i am going to go to the track @ 30psi which is what I am at now, see how it runs, and then make adjustments from there.

 

I don't think you need a open down pipe just get better cams and you will need to rev the car out a little more.

 

Well, it will help. Your loosing weight and it should add some power. But it will be very minimal gains on both ends and I cant say youll see a difference in times from it. I would absolutely invest in the S3's as they would be way more beneficial then taking the exhaust off.

 

I PM'd ER about getting some cams so I think I am going to get those either way JW about the springs. I'm sure I can pick up a ton of top end.
These cams I have now were great with the stock IM, .63 housing I had before. Tons of midrange

 

Check into ER's test pipe dump thing. It's the best of both worlds. I run open DP with s3s right now all the time and I will tell you it is not very practical. I know some people have gotten some unreal gains by running open dump due to freeing up restrictions but I wouldn't recommend it unless you tune for it. I'm going to try to get a back to back to compare open dp vs stm's aluminum exhaust here shortly once my arm heals.

On to the weight savings.. if it's still a street car get the aluminum exhaust. It weighs 9lbs total! It's an amazing piece. Basically if I were you I would run the aluminum exhaust for weight savings and ER's test pipe dump for the power aspect. That way you could run one tune and cover your *** at all times while still having the best of both worlds.

 

Well I was more so doing no exhaust for the weight savings, if it won't hurt the car I will do it. If it helps performance that's great.
I have the buschur exhaust already and it would cost me almost 500$ to switch to the STM exhaust which I have considered but don't find worth it. If I were stock exhaust I would do it


I would imagine driving around no exhaust would be horrible lol. This will be a 1 or 2 time thing and it'll be full exhaust from there on out

 

Just run two maps and one for the track and the open DP and you won't regret it. I'd recommend something like a turn down to keep the heat off the underside of the car for when you do pull the exhaust though.

 

just ordered the cams and springs from STM. i saw on facebook today they were running a special on GSC products so it was perfect timing. if i didn't live in the same state i could have saved 50bucks. ended up only saving $4 because of tax but oh well lol

i will do a turn down for sure! where is ER cutout? does it replace the cat section?

 

http://www.shopenglishracing.com/Eng...Pipe-Dump.html

Check it out.

 

Yea that's where I figured it'd be. I'll prob dump it just passed the oil pan

 

I like.

 

I'm going to pull the trigger soon on it and try to see what it can do.