onefast93RX7

iTrader: (5)

The guys at Gotham custom made me a 4" dp, mid-pipe with resonator, and 4" exhaust. Everything was ceramic coated black and the dp was wrapped in black. Everything is V-band for easy installation.

The wastegate is routed back into the 4" dp
(picture is 4"dp next to gotham's 3" dp)


The 4" midpipe with magnaflow resonator
(4" midpipe next to 3" midpipe with resonator)


4" exhuast splits into two 3" duals with gotham's muffler

RacerXtreme7

iTrader: (2)

NICE fabrication!!! It's not going to be too quiet though eh? Small mid resonator. A Borla X1-R would have been a good mid muffler/ resonator. Over all
very impressed with the fab work!!

~Mike...............

mr2foryou

VERY NICE. PM me the price? If not, that's cool. Just curious.

Dee E.

onefast93RX7

iTrader: (5)

Gotham's done a lot of work on my car and gave me a good price on it. I should have a vid of the car dynoed soon. The exhuast isn't that loud, not as loud as the apexi dual muffler one.

KNONFS

iTrader: (14)

WOW

Is the spool time any better?

Northern7

iTrader: (1)

Damn that does look nice! I may rethink my options.

iceman4357

iTrader: (2)

I am going to have someone do this for me too while i have my car apart. What sized turbo do you have?

Rx7_Nut13B

iTrader: (1)

I demand Videos LOL

And how did this improve your spool time on what turbo.

I am going to order the stuff to make one but the man thing is that i want a quite but powerful exhaust with my GT42

onefast93RX7

iTrader: (5)

I'm still waiting for Steve to schedule me in for a dyno tune when he comes back in town. Hopefully soon.

Howard Coleman

iTrader: (6)

congrats on a really well thought out and executed exhaust.

while i have my doubts about not having to talk to the guys in the blue uniforms re noise it should really crank top end.

i am coming around to the conclusion, already held by many, that 450+ rwhp rotaries are really being held back by many of the traditional 3 inch systems.

i run two TO4s that each have their own 3 inch downpipe. the two pipes slip into a Burns Stainless 2 into 1. the 2 into 1 has a 3 inch (V band) back end and i run a 3 inch straight thru Borla 40944 mid muffler and a Racing Beat catback.

measured just before my turbo my backpressure is 16 psi at one bar boost making 364 ft pounds torque at 6100. just after 6100, where my setup should really start to come on it falls on it's face.

it might be my exhaust. i do note that the Racing Beat catback is fairly quiet around town and my other catback is really loud. i am going to switch catbacks for my next dyno session in march. if it makes a significant difference i may just go dual 3 inch all the way back... or just run the less restrictive CB.

if i do this i will have to incorporate some sort of removable baffle system.

that may just be the right setup... a really unrestrictive exhaust system w a removable baffle.

nice exhaust Gotham.

howard coleman

RacerXtreme7

iTrader: (2)

Electric exhaust cut out is your friend

http://cgi.ebay.com/ebaymotors/Elect...spagenameZWDVW

http://cgi.ebay.com/ebaymotors/Race-...spagenameZWD1V

http://cgi.ebay.com/ebaymotors/QTP-3...spagenameZWD1V

A7X

wont that throw your tune way off?

Howard Coleman

iTrader: (6)

straight exhaust might work at Bonneville but not at any road racing track.

i remember being passed by a very fast RX2 on the straight and it just about removed my eardrums. this was thru my helmet and earplugs and before the SCCA mandated mufflers for any rotary.

the NOISE was the first thing i remember from my first rotary encounter. little did i then realise how much a part of my life they would become.

later, even w the SCCA mandated (smallish) mufflers rotaries remain the loudest engine ontrack. a couple of years ago at Road America you could hear the LMP2
20B over 50 other cars ontrack. you could hear it make every shift at every spot on the 4 mile circuit.

nowadays most tracks have 105 Dbs limits and there's no way a cutout would work. plus it would be godawful in the car.

making max power? sure but.

no, i will fixture something like the HKS insert.

and yes, when you significantly change your backpressure you do need to work the tune.

hc

RacerXtreme7

iTrader: (2)

You guys need to use your imagination a little more. Why not run a dual system, one with a baffled muffler, one with a straight through muffler. The cut out could be to run one muffler (baffled) then opened to run both mufflers. Or use a muffler such as the "warlock". http://store.summitracing.com/egnsea...9&autoview=sku I don't think it'll stand up to rotary temps (In the pic I see a all stainless version although I don't see it available), but I'm using it as an example. Its a dual purpose muffler, single inlet, dual out. One out is straight through perf core, the other out goes through a series of baffles and perf with packing. These come with a block off plate that uses buterfly nuts to plug the straight through outlet. A simular muffler but better built with higher quality materials would be really nice to have. Run the baffled muffler for the streets or long drives, use a electric cutout to open the straight through section up for full throttle or race day. It would be nice to set it up using load (map based) or even throttle postion (TPS) along with a "ON OFF" switch too.

~Mike..............

Rx7_Nut13B

iTrader: (1)

I just ordered my entire exhaust piping, it will be a 4in DP, with a 4in to 2.5in Y into two Metal 2.5in cats then back to 4in in another Y.

I hope this will help with the loudness and still keep the flow up there.

In the back it will be a 4in Muffler

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88t2romad

curious on the price of something like that?

I really need to replace my current exhaust...

Can you pm me?

onefast93RX7

iTrader: (5)

romad,

it should be cheaper for your car since a t2 has more room

A7X

i was told a cutout will throw your tune way off... is this not true?

onefast93RX7

iTrader: (5)

it's true, it leans the car out. Most of the setups that Gotham has done is tied up with Motec or Haltech to activate it under a certain boost. That way it's tuned for the e-cut out.

Here's one on a 3 rotor about to be wired up to a Haltech E11

The downpipe is a 4" to a 4" e-cut out then routed back to a 3" midpipe

Rx7_Nut13B

iTrader: (1)

Why would it lean it out, it would cause boost to build faster, so you would just have to adjust the map for boost earlier.

Marcel Burkett

I'll be going with a complete 4" system , front to back and two BORLa XR1 race mufflers , any idea what the noise levels would be like?

onefast93RX7

iTrader: (5)

if it didn't lean it out, then why would you have to adjust the map for boost earlier? (that means it leans it out in lower rpm)

onefast93RX7

iTrader: (5)

my car isn't as loud as the apexi dual n1's, it's got a deep rumble to it.

Howard Coleman

iTrader: (6)

how bout building a large exhaust system, one that would generally be too loud, and adding a choke plate in a straight section. drill a bunch of holes in the chokeplate so it would flow to your taste when closed....

make the plate adj from open to closed.

hc

jon4825

iTrader: (1)

nice 4". please post audio/video clip