What do you guys use for the exhaust exit? My Ti exhaust blows out flames on decel and shifting when it isn't pouring gobs of heat while on the throttle.

My bumper is currently melting during track days. My exhaust tip exits right where it should with the JDM bumper and doesn't stick out an extra couple inches or so like I have seen with some exhaust tips.

A lot of the cheaper "carbon fiber" options will not cover the area of the bumper that is melting (gray area on the bumper up to the car paint color). The only 2 options I have seen from CFRP that would work for where my bumper is melting is Varis and Voltex. Those 2 are expensive and I do not know how much better those would handle the heat than my bumper.

I could put heat reflective tape on the bumper. That would look a bit retarded but would work. (I use the silver Aero-Lite stuff)

I could fab up some stainless steel sheet metal and rivet it on. That seems like it would be more effort than the heat reflective tape but be more durable (and heavier).

Or, do most of you who track your car just not even worry about the bumper or don't have this issue?

 

Don't have this issue on my car. Running USDM rear bumper and my exhaust exits maybe 1cm or so farther back from the bumper. AFAIK I don't spit flames though.

 

Might be because of the shape of the USDM bumper as opposed to the JDM bumper too. The USDM bumper is a bulgey smiley face and exhaust exits near the very end of the car. The shape of the JDM bumper might be what is causing this: The JDM bumper slopes up and back from where the exhaust exits putting more heat into the bumper, the exhausts for JDM bumpers aim diagonally upwards when sloping back for the rear bumper and the air flow coming from the bottom of the car might be "hugging" the shape of the rear bumper pushing into the low pressure zone behind the trunk.

 

I would first address the main concern of why your track car is running so rich that it spits flames at any possible point.

once that is addressed, I would ignore it because its a track car, but thats just me. Their are hundreds of people here with exhaust/jdm rear combos and rare you hear about one melting, do you have pics of said damage?

otherwise, fab or have something fabbed up to control heat with looks being a secondary concern. gl

 

This is for my DD/HPDE/AutoX/drag car. It is not a dedicated track car.

I have gone back and forth with Aaron at English Racing on the low boost, 92 oct tune after track days. It is as rich/lean as it needs to be.

It spits out flames on shifting and decel.

I imagine it may be because of the timing advance in the high rpm, low load cells that was implemented because I was getting shift knock. Or maybe Aaron just throws the flame spitting in there because people like it or it serves a functional purpose. Granted, I don't know exactly why it spits flames or know if I can have my cake and eat it too.

 

High timing advance won't cause flame spitting, it would be the opposite actually.

 

Your car is spitting flames because it is tuned too rich and burning unspent fuel. It needs to be leaned out, you will then see more power. Aaron may not feel comfortable leaning it out anymore because there is a fine line there where it might start to detonate. Do you run a CAT? That might stop some of the flames...

 

I built an aluminum heat shield that fits perfectly inside the curved cutout of my USDM Evo9 bumper cover... it had an unsightly hole melted in it because of a misaligned exhaust and shoddy overall install job of the exhaust (now replaced).

I'm now using a JDM-style exhaust (Mine's Ti) so the tip stops well short of the bumper cover, so I'm thinking there is likely a decent amount of heat coming up into the bumper cover at the exhaust tip area... no issues with melting or deformation of my bumper cover at all, after about 2 1/2 years, many autocrosses, and about 600 track miles.

The aluminum I used is .031" thick (1/32"), and I either bought it at Lowes or Home Depot, can't remember which now.

I wouldn't bet my life on whether the heat-reflective tape would work or not, but I THINK there's a chance it would... especially if you put a layer on the bumper cover itself, then adhered some sort of "air-trapping insulation layer" on top of it, like fiberglass cloth you can buy at Vato Zone for fiberglass work; and then stuck another layer of heat tape over the fiberglass mat.

 

...

 

USDM bumper with carbon heat shield. Looks good but not really functional.



JDM Bumber with HKS heat shield. Got a bit of color but worked.




I have learned the metal ones the one which working really. My car do generate a LOTS of heat around the exhaust tip. Set up and ALS working together to make the heat , but no issues .



Sometimes we even took it to the ultimate test ... lol (this is just part of the flam throwing that day, )



So i vote hands down for the metal shield. Also bigger is better

 

Good deal. I can't find the HKS one for the JDM 9 bumper anywhere though.

 

I got it from some vendor from here. I cant remember who was that. Sorry.