I got a used pettit downpipe for my FD and I've heard they're really close to the car body when installed. When searching and combing through old build threads the only picture I found that kind of shows the clearance is here. It's pretty old, I'm not sure if the design has changed over the years, and it's from the wrong angle to show much. Does anyone who has one have pictures of how close their pettit downpipe comes to the body?

I'm looking for this info because I would like to build a proper heat shield for it if there is room to do so, but if there's no room I'd rather know and just send the downpipe out for a coating now. I'm a couple of weeks away from taking the car apart at this point. I'm estimating for the sake of installation I'll need at least a half inch of clearance since the heat shielding will probably be about 1/4" thick.

Thanks in advance to anyone who can contribute

 

IMHO get it Jet-Hot coated. I've done Jet-Hot 2000 on my downpipe and on previous ones I've owned and it works like a champ.

Also access to some of the fasteners downpipe to turbo is tight so having some sort of wrap or heat shield could get in the way. Coating will be zero problem.

Dale

 

Thanks Dale, I'm pretty sure I'd just contour or put cutouts in the shield where fasteners are a concern, maybe have a second layer that fits over them. Looking at the thing, it's pretty clear that a couple of the fasteners are going to be a pain. I'm unsure of the efficacy of the jet hot coating in reducing the radiant heat, I've only seen surface temp measurement claims without much about the methodology, and the less heat the better. Multi layer metal heat shields are the gold standard for a reason, of course, and are not difficult to make.

 

I can attempt to get photos, but I'd personally just coat it. There's at best a fingers width between the frame and the downpipe if I recall correctly. As for the bolts, the bottom rear specifically is a pain and requires some clever ideas or a stubby end wrench.

 

It would be appreciated if it is possible. My downpipe came with a short bolt, I'm guessing that is intended to replace that bottom rear stud. I'm just hoping none of them give me too much trouble, the mid section had a stubborn nut that galled a bit coming off and it was a pain repairing the threads on that inconel stud. Thread file wasn't sharp or hard enough, I had to go at it with a good triangle file.

 

My Pettit downpipe is 20+years old. If yours is the same diameter or larger, there is not much room for anything thicker than heat wrap.

 

Attached a shot from above and below. Bought mine in 2023.

 

Thank you for the pics guys. This gives me a much better idea of how tight the space I'm working with is. Looks like .5" - .75". Might be tight enough that a spot welded on integrated heat shield makes installation difficult. I may just get it coated, and hope that's effective enough that I don't have more radiant heat under there than I would like. Might wrap it over the coating where it is closest to the body.