Hello there. I've been reading quite a lot on this forum and I have a question that maybe some of you will be able to help with. Last year I bought a mk2 race rolling shell and decided to make it into a rallycross supercar class build. The issue in my country is that you first need to do at least one season in a lower division before you could race in the supercars. Due to this fact we decided to "throw together" a 1.6 engine with spare bits we had from our 16vt audi quattro supercar. The engine we cobbled togethe is an ACE head on a AEK 1.6 101hp bottom end with KR pistons. The engine turned out not so bad turning out about stock KR power at 136hp on the dyno. Due to covid the season got cut short and we will need to do another season in the 1600 class and wanted to experiment a bit for more power as the engine is fully stock parts wise. The exhaust we have on is the so called LHD manifold, better known here in Bulgaria as the 20th aniversary mk3 manifold. The downpipe fitted( the 2 into 1 section) is quite short to merge into the single pipe due to the vehicle being an original syncro "4wd". I have an 8v downpipe from a PB which is quite longer and i thought to throw it in there but it seems to be a smaller diameter inside and I am wondering if this will be a choke. The head will be getting ported and was wonderinf if the 8v downpipe will help with any mid range torque gains as I've seen some ABF builds on here with the 8v dp. Appreciate any thoughts on the matter will be appreciated.(sorry for the long first post )
Curently the rev limiter is at 7000 as the dyno plot starts dropping after 6k. Forgot to mention it is running an adapted intake manifold from a 1.8t 180hp withe the oem 300cc injectors on a MegaSquirt with 100 octane fuel
At that power and revs, you might be ok with the downpipe. The restriction if I remember correctly is right at the flange, wouldn't be the hardest thing to bore out.
Great to read about clubman motorsport in another country Keep tuning (and communicating..) Have done a bit of Rallycross in my time too, in a mk1 Golf, quite a while back Jon
the tubular manifold is a bit longer than the cast version so that might cause you clearance issues to the subframe so bear that in mind. with the abf tubular downpipe all you need is a mk2/3/corrado decat pipe to mate it up to the rest of a mk2 golf exhaust system, note the pipe will be 57mm so you'll need a reducer if you're running an 8v system. the mk2 16v system would fit straight up to it though
Thank you for the advise. Will be removing the head soon to get it ported and will tackle the exhaust then. I will also try and post a couple of photos of the process
