Best exhaust for an autocross

ITR640 · Post by **ITR640** » February 21st, 2004, 3:03 am

I'm going to begin autocrossing more heavily this year than any other year. I was wondering if anybody had any recomendations for exhust systems. Its got to meet SCCA stock class rules. I dont care if its loud or not, I just want the best exhaust you can get.

Bbasso · Post by **Bbasso** » February 21st, 2004, 11:57 am

Check your local autoX rules some have db limits on exhausts.

ITR640 · Post by **ITR640** » February 22nd, 2004, 2:47 am

You can run cut outs so I'm guessing they dont care.

bbqman · Post by **bbqman** » February 22nd, 2004, 9:55 pm

Generally for auto-x, any system that retains the cat will be legal for Stock class. After that, the best system is the one that weighs the least.
Power gains by exhaust are almost insignificant in an auto-x enviroment.

ITR640 · Post by **ITR640** » February 22nd, 2004, 11:03 pm

Good point, I was doing some research and found that Spoon makes the lightest one, but its also one of the most expensive. I was considering getting mugen, comptech or spoon. What do you think.

Azcheron · Post by **Azcheron** » March 5th, 2004, 7:44 pm

not sure if its light or not, but when i put the tanabe super racing medallion on my car, i gained more power than i ever expected, just some food for thought

Champ R · Post by **Champ R** » March 7th, 2004, 10:10 pm

Fujitsubo RM-01A gets my vote.

ITR640 · Post by **ITR640** » March 9th, 2004, 3:39 pm

Where did you buy the Fujitsubo exhaust from. Also what are some specs on the exhaust all i could find was info written in japaneese.

Chris N · Post by **Chris N** » March 9th, 2004, 3:54 pm

There is a problem with the Fujitsubo RM-01A for autox stock classes:

You have to keep everything from the cat forward stock.

Problem: The Fujitsubo has a JDM-length b-pipe. This is 3-4 inches LONGER than the ITR stock bpipe and the mugen twinloop b-pipe, etc. Most 'jdm' brand exhausts come as JDM and USDM length... this is one of the only ones that is only available with the JDM length bpipe.

One member of honda-tech actually cut the Fuji bpipe and had a flange welded on to fit it to the stock cat. After spending $750+ dollars on an exhaust, the last thing I wouild want to do is hack it up, but if D stock is that big a deal to you and you NEED an exhaust and are willing to do this - its probably worth it. It is very light compared to the stock system (I'll have a weight comparison in a few weeks) and I made 8whp on the dyno just front swapping out the stock cat/stock exhaust for the Fujitsubo and an appropriately sized cat. (larger diameter)

Just be aware that if you were to get the exhaust, and try to bolt it up, it would NOT fit with the stock cat.

ITR640 · Post by **ITR640** » March 9th, 2004, 6:32 pm

Yea I like the Fujitsubo but the whole cutting thing doesnt sound that good. The Spoon exhaust is still lighter than the Fujitsubo.

Exhaust B-Pipe Data (Integra Type R)

Pipe Diameter (OD) Flow Rate Weight
Spoon 60.5mm (2.38") 135l/sec 5.9kg(13lbs)
Stock 57.2mm (2.25") 115l/sec 8.8kg(19.4lbs)

N1 Muffler Data (Civic Type R / Integra Type R)

Pipe Diameter (OD) Flow Rate Weight
Spoon 60.5mm (2.38") 139l/sec 3.6kg (7.9lbs)
Stock 57.2mm (2.25") 112l/sec 8.5kg (18.7lbs)

[url]http://aj-racing.com/spoon-sports/integra-inex.html[/url]

When the Fujitsubo exhaust weighs 11.2kg.

[url]http://www.fujitsubo.co.jp/search/prod- ... D=00000150[/url]

Chris N · Post by **Chris N** » March 10th, 2004, 12:45 pm

Good info, but its kind of worthless to compare an axleback/muffler to a full catback (b pipe and axleback) as far as weight, isn't it?

ITR640 · Post by **ITR640** » March 10th, 2004, 3:06 pm

well if you add the b pipe and the n1 muffler together its still lighter than the fujitsubo. but im still not sure i might get mugen just so i can say "hey this ones got mugen exhaust". lol

Chris N · Post by **Chris N** » March 10th, 2004, 9:07 pm

what bpipe? The spoon B-pipe is very expensive, hard to find, and also jdm-length.

BTW - the fujitsubo exhaust (catback) weighs LESS than the stock ITR b pipe... I weighed them when I installed mine.

ITR640 · Post by **ITR640** » March 12th, 2004, 3:41 am

What about the Mugen sports exhaust for the ITR. Does anyone have any expierence with it. How much does it weigh? How much power is gained? I'm pretty its not JDM length.

TJ R · Post by **TJ R** » October 8th, 2005, 7:53 pm

Interesting and useful information. What about a custom exhaust? Will there be any difference as opposed as getting a branded exhaust? Just wondering because I'm also reasearching what exhaust to get.

punkaddic · Post by **punkaddic** » October 10th, 2005, 6:16 pm

Stock exhaust and removed bottlenecks

jetydosa · Post by **jetydosa** » October 11th, 2005, 7:55 pm

The stock bpipe is crap. Heavy as hell and bottleneck'ed. Id say your best bet if you wanted to stay DS and didnt want the hassle of cutting up your brand new exh, get the Comptech one. The fitment is great and sounds pretty good too. I cant comment on weight.

Other than that the Fujit setup, while very nice, is a few lbs heavier than the T1R/Spoon N1 combo I had been using. Its a helluva lot quieter though.

vtecjerry · Post by **vtecjerry** » October 20th, 2005, 9:29 pm

The comptech was on my r when I purchased it, the first resonator got all rusty and broke apart inside it. Swapped it out for th t1r and I love it.

cltitus · Post by **cltitus** » October 23rd, 2005, 8:04 pm

right now im running str8 downpipe tell i get my comptech but yea light is better for auto-x

bbqman · Post by **bbqman** » October 25th, 2005, 11:35 am

Right now, if you are looking to do what you can for autocross gains, the Magnaflow is the way to go.
It is a system that doesn't make you lose power as some do that...and the weight savings is significant.
Some of the top ITR DS racers are using it.

ITR640 · Post by **ITR640** » November 8th, 2005, 8:32 pm

Thanks for all the info.

I just checked this thread, haven't been here for a while. I've decided that kumho's would be a better purchase then an exhaust.

the Magnaflow, because everyone else is doing it, seems like the way to go.

PY>***

Utilitarian · Post by **Utilitarian** » November 14th, 2005, 10:34 pm

As your signature says, buy some Kumhos instead. Any gains you'll see in exhaust will be nill. Besides, you'll have way more fun on R comps if you aren't already on them. The V 710's seem to be the best bet.

Trust me I raced/daily drove on Azenis for 2 yrs.

bbqman · Post by **bbqman** » November 16th, 2005, 1:25 am

ITR640 wrote:Thanks for all the info.

I just checked this thread, haven't been here for a while. I've decided that kumho's would be a better purchase then an exhaust.

the Magnaflow, because everyone else is doing it, seems like the way to go.

PY>***

I just reread your initial post... If you want to be competitive in DS with the R, better get those V710s or a3S05's before the exhaust...next Koni double adjustables......

CTteg · Post by **CTteg** » November 29th, 2005, 11:47 pm

I agree with the previous two posts. If you're relatively new at autocross and have a limited racing budget, my suggestion is to do the following:

Year one: learn how to drive with what you have. A lot of classes have street tire classes, and better yet, street tire *and* novice combined. Learn what a stock car does. Heck, you might decide autocross isn't your cup of tea, and if that's the case, you just walked away with a lot of $ still in your pocket.

Year two: get some R-compound tires (or Azenis) and race in a Stock class, where you're not tempted to spend loads of money on questionable mods. I'd suggest getting the cheapest R tire available, such as the Kumho Victoracer. Also don't discount something like a drag radial. I used the Nitto drag radial as my first R tire, and they were great (and I could leave them on the car for the season - which meant I didn't have to buy another set of wheels).

Year three: performance shocks. Lots of options here, but in Stock you'll need to retain your springs, so the best bet would be maybe Bilstein Sports on the low $ end, Koni off the shelf single adjustable (rebound only) in the middle $-range, and maybe the Koni SSPS double adjustable (rebound and compression) at the higher $ end. Again, if you're just starting out, I'd opt for the Bilsteins or the Koni single adjustables. The double adjustables just add a bunch of $ and another layer of confusion in terms of proper adjustment settings. You'll have enough on your mind and don't need to be worrying about the correct settings. If you get the Bilsteins, you'll probably want to eventually (in a few years) upgrade to a manually adjustable shock (i.e., the Koni). But the Bilsteins are still a GREAT shock. Plus you put them on and don't have to worry about settings. If you have an ITR (I'm assuming that's why you're here) and don't mind a harder ride, get the Bilsteins Sports over the HDs.

Unless you're nationally competitve, keep it simple, fun and as inexpensive as possible if you're just starting out. If you're not careful, this sport can drain your wallet faster than than an ex-wife who just found out you have a new girlfriend. Trust me on that one.

keepin it N/A · Post by **keepin it N/A** » December 12th, 2005, 10:55 pm

im gona b using a spoon sports cat back ex. i dont think you can go wrong with spoon, all thier cars and parts are geared twords auto cross
just a suggestion.

ITRCA

Best exhaust for an autocross

Best exhaust for an autocross

auto cross exhaust