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Downpipe Battle - IE VS MAP VS COBB VS Trackslag VS HPA
- Thread starter Jargon
- Start date
I was in their shop today and they have a stock S3 lined up for next week so hopefully they will be able to bring this DP to market shortlySomeone please donate your stock R/S3 so we can have this downpipe!NYC is quite a distance from Denver, or I'd go and do it lol. Looks amazing.
GTI Jake
Autocross Champion
- Location
- Charlotte, NC
Not sure. I just asked for a 4" DP with a 4" GESI cat as far downstream as possible to mate with my existing custom 3" midpipe that they had designed to add a 17950 to a little over a year ago. Other than that I left the rest to them.
These guys have a ton of experience and have designed a lot of exhausts etc for some pretty high end cars, so I pretty much put my trust into what they came with and I'm happy with the end result. I'm sure if you reached out to Nick at 485 he would be more than happy to provide details. Genuinely nice crew over there that I'm sure would be happy to answer any technical questions.
ShagginGSW
Go Kart Newbie
- Location
- MD
That is unless......ZZZZZZZZZZZZZZZZZZZ.
If you look closely they used what looks like 1/8" sheet ( judging by the size of the inside weld). There's clearly a flat edge where the arrow is. The small bead on the outside it either an autogenous bead to clean up the area or done with an .045 filler rod. That was a good idea to save the space of a 3-4" transition. You would need to build an argon box if you don't have one already and do that weld inside to prevent discoloration and sugaring on the outside.
GTI Jake
Autocross Champion
- Location
- Charlotte, NC
I can see that itās not one piece, which isnāt ideal but I can see why theyād do it for a one off part.
Currently material shortages have raw stainless bar stock prices insanely high. If a bunch of shops who plan to offer 4ā downpipes went in together to increase volume thatās the biggest factor for machined parts pricing. Example:
1 V band $750
100 V bands $50 each, but itās a lot easier to buy that many across four shops rather than just one putting up $5,000.
Looks more like they turned down a second v band on a lathe, but either way itās not ideal.
Personally I wouldnāt do the purge box in this application, because thereās no way to clamp the part to keep it from warping.
I always have v bands clamped down to a fixture or v band while welding to keep it perfectly flat, since I donāt have a mill to fix it if I let it warp.
You can make a box big enough to use a V band purge block or a TiCon copper chill block inside. Another option is to use a trailing shield box on the outside as you weld the inside.
https://www.ckworldwide.com/products/tc-3r-premium-trailing-shield
https://usaweld.com/products/4-single-v-band-purge-plug-w-vent
But I agree, having a solid V-band would be the best way to go. I think Trackslag is using the same 3.5" V-band I linked from the UK and welding the 4" to the outside of it.
https://www.ckworldwide.com/products/tc-3r-premium-trailing-shield
https://usaweld.com/products/4-single-v-band-purge-plug-w-vent
But I agree, having a solid V-band would be the best way to go. I think Trackslag is using the same 3.5" V-band I linked from the UK and welding the 4" to the outside of it.
GTI Jake
Autocross Champion
- Location
- Charlotte, NC
Probably a moot point, I doubt Iāll end up offering 4ā for these cars.
Furick is developing trailing cups too, so my goal is to purchase a weld positioner & one of those along with TIG aesthetics positioner fixtures.
So many cool tools in the industry, just adds up quick especially with this being a side gig.
I made a chill block first thing when I bought my TIG
I know the feeling... when I retired from the Army in '17 I decided to open my own business doing detailing/motorsport work from home. I ended up closing shop at the end of '19 because the market in my area is saturate with cheap places and people that don't value good work and rather have the cheapest option available. I ended up being almost $20k in the hole. Granted I have all the tools needed if I ever decide to do something.
ShagginGSW
Go Kart Newbie
- Location
- MD
Don't notice much of a sound difference vs my old IE DP.
It hits peak boost at about the same rpm as well (~3400rpm..since I'm at 6k elevation we take a hit on spool so even though I'm standard housing I hit peak boost about same rpm as sea level XLs), however, the IE DP was when I was on the stock DI (no MPI) where peak boost was @ 30psi on E30.
I'm now on MPI and I just completed a live road tune session with Ed @ EQT on Tuesday for E40. I asked for a moderately aggressive daily tune since I still have E85 tune to go which I will request be fairly aggressive. Anyway, he settled on peak boost at 32psi with the tune so although I'm hitting peak at same RPM with the new DP vs old IE DP I'm also 2psi higher on the peak boost mark I have hit.
I would have liked to get a before and after dyno session in to see hard whp & wtq data, but that's unfortunately not going to happen.
I wasn't at the shop for the actual install so I didn't see it go in. I'll have some dyno #'s next month since I'm doing the E85 tune on the dyno here locally with Ed, but again won't really help much with the old DP vs new DP comparison.
BTW - they got a stock catback R In the shop today so they are working on the final production version now
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ShagginGSW
Go Kart Newbie
- Location
- MD
Ready to order in catless or GESI high flow cat versionā¦. https://www.485designs.net/shop-online/mk7-golf-raudi-s3-4-downpipe
