Header upgrades
08-24-2018, 11:51 PM
#16
stock diameter tubing or larger than stock?
Any of the units worth buying aren't going to be a direct fit and will require some fabrication, if you've got a good fab guy this won't be an issue.
I purchased the standard 996 GT3 FVD long tube headers and didn't like the fact that they choked down to 55mm at the collector so we cut the collectors off and made proper merge collectors that went down to 63mm and then back out to 70mm on exit...which is what the rest of my exhaust is.
FVD makes another set that is 70mm collectors but will require a little more fab work based on collector placement. Have a feeling the Dundon units, if you could even get just the headers alone, would also terminate at a spot that's going to require some fab work to get them to work.
Don't expect gains that the newer cars see on a 996, but there are some to be had there none the less mainly in mid range torque. My lap times pre and post headers aren't too much different but the sound is even better and I had to rebuild my old exhaust anyhow so it was fun to integrate long tubes into the build.
Any of the units worth buying aren't going to be a direct fit and will require some fabrication, if you've got a good fab guy this won't be an issue.
I purchased the standard 996 GT3 FVD long tube headers and didn't like the fact that they choked down to 55mm at the collector so we cut the collectors off and made proper merge collectors that went down to 63mm and then back out to 70mm on exit...which is what the rest of my exhaust is.
FVD makes another set that is 70mm collectors but will require a little more fab work based on collector placement. Have a feeling the Dundon units, if you could even get just the headers alone, would also terminate at a spot that's going to require some fab work to get them to work.
Don't expect gains that the newer cars see on a 996, but there are some to be had there none the less mainly in mid range torque. My lap times pre and post headers aren't too much different but the sound is even better and I had to rebuild my old exhaust anyhow so it was fun to integrate long tubes into the build.
So any New headers will need fabrication to connect direct to muffler. That is not a problem for my workshop.
based on that you are suggesting the best option would be? Thanks again
08-26-2018, 03:42 PM
#17
Race Car
If you can get Dundon to make you his long tube stepped headers without the rest of the exhaust I think that’s the best, but most expensive, ones to get.
Fvd makes a set with 70mm collectors that are nice but my personal opinion is the 70mm collector is a little big for our 3.6 cars.
Look for my exhaust thread I took the regular fvd long tubes and cut the 55mm collector off of them and opened it up to 63mm for the best bang for the buck approach.
Fvd makes a set with 70mm collectors that are nice but my personal opinion is the 70mm collector is a little big for our 3.6 cars.
Look for my exhaust thread I took the regular fvd long tubes and cut the 55mm collector off of them and opened it up to 63mm for the best bang for the buck approach.
08-26-2018, 08:34 PM
#18
Rennlist Member
I have a semi related Q - not looking to derail this topic - but I removed my (mercifully still functioning) cats, and put them on a shelf for the day I may need them.
I have a fabspeed x cat bypass, everything else is stock,
Not looking for anymore volume, but would be interested to know if there's anything complementary I can be doing here. I am thinking of a SW tune to remove the 02 sensor CEL and maybe take advantage of the lack of cats.
Grateful for any thoughts based on actual experience/measurements, either upstream or downstream.
Cheers
Matt
I have a fabspeed x cat bypass, everything else is stock,
Not looking for anymore volume, but would be interested to know if there's anything complementary I can be doing here. I am thinking of a SW tune to remove the 02 sensor CEL and maybe take advantage of the lack of cats.
Grateful for any thoughts based on actual experience/measurements, either upstream or downstream.
Cheers
Matt
09-15-2018, 09:16 AM
#19
Burning Brakes
If you can get Dundon to make you his long tube stepped headers without the rest of the exhaust I think that’s the best, but most expensive, ones to get.
Fvd makes a set with 70mm collectors that are nice but my personal opinion is the 70mm collector is a little big for our 3.6 cars.
Look for my exhaust thread I took the regular fvd long tubes and cut the 55mm collector off of them and opened it up to 63mm for the best bang for the buck approach.
Fvd makes a set with 70mm collectors that are nice but my personal opinion is the 70mm collector is a little big for our 3.6 cars.
Look for my exhaust thread I took the regular fvd long tubes and cut the 55mm collector off of them and opened it up to 63mm for the best bang for the buck approach.
I have a complete Mk 1 996 GT3 Manthey K400 exhaust system (the same as the K410 for Mk 2 996 GT3) the system uses the 70mm diameter merge collector outlet.
When fitted to a Mk 1 996 GT3 along with a Cup air filter and MAF delete, that exhaust produces 400-405 hp. The manifolds and HJS 200 cell cats along with the increased diameter pipe work, are responsible for the majority of those gains imo.
Last edited by Atgani; 09-15-2018 at 10:12 AM.
09-16-2018, 10:58 AM
#20
Rennlist Member
I put on a 997.2 Cup exhaust. It was bolt on, and has small race cats, although it did require a center exit exhaust. I dyno'ed before and after and there was virtually no difference, but it saved 70+ lbs from the rear of the car, which was noticeable.
09-17-2018, 09:45 AM
#22
Rennlist Member
Loud for Laguna Seca, NCM or other sound restricted tracks, but otherwise not bad. At WOT at 7k rpms, it sounds perfect.
The Cup headers are short, and I they are different from the GT3 headers. No side mufflers, single inlet on each side into the center muffler.
The Cup headers are short, and I they are different from the GT3 headers. No side mufflers, single inlet on each side into the center muffler.