Modena 1

But you do lose tq I believe. No one is really talking about that.

John Chan

Lose tq with after market header setup?
Not in the DMS system in my car. Dyno showed tq gain from low to high RPM.

Charles@dundonmotorsports

If you are looking for a full header back setup then our Race header and side connecting pipes using the stock center muffler is the way to go. We have not had the chance to test ourselves on a 2010-11 3.8 GT3 (non RS) but i see no reason our results would be any different than all the rest.

Our setup is just this, very quiet around town, ZERO DRONE because we use the stock center muffler with the small bypass inlet.

Flaps open and its go time, a little louder than a center bypass, but a MUCH better sound, and you get the full performance as well.

Some, or many, other manufacturers yes lose low end TQ, andsometimes a lot, but our Race header setup makes power everywhere with no loss. dyno proven and by more than just me.

The two dynos below are NOT running the same headers, the headers are specific for a 3.6RS and a 3.8RS. a 3.8 GT3 would run the same headers as the 3.6.

Here is John's Car, 3.6 RS




Here is a 3.8RS, FJ's car

RobT 394

M&M center with side deletes is a great street setup. The center will crack if you track. All centers crack if tracked hard other than the cup. I have cracked three of them so far.

Sharkwerks track exhaust will not crack as it is just a straight pipe. I have one for sale if interested. Taking the car off the track and pulling it to go back to the M&M.

TRAKCAR

All centers crack, except the M&M, oem Ti quickly, steel a bit slower, Shrky slower still.
Side muffler delete with our without cats and a sturdy strong, nice sounding center is the way to go.

I did not lose TQ with that setup, runs cooler more HP, good sound.

D-Uber Cars

On my 2nd. DMS system. First was on 996GT3, current on 997.1RS. DMS is engineered specifically for your engine version. First class handmade workmanship, makes power with no loss in TQ, no drone and sounds great!

runet

I'd say you always loose torque below 3k in a GT3 when replacing stock exhaust with something with less resistance in the pipes. That has been very noticable on my own GT3 when moving away from stock, and every single torque curve I have ever seen that goes below 3k show the same. The curves are usually cut at that point, hiding this issue.

I don't believe it is possible to keep up the torque at very low rpm's on a high revving NA engine when the exhaust is freed up for maximum power.

Charles@dundonmotorsports

I actually have a few dynos going as low as 15-1800rpm. I will try to dig those up.

Most of mine I start at 3-4000 because I am not needing to spend excess time down there, so it is pointless to start a dyno pull at 1000rpms if you are tuning or working at 5-8500.

r6elmo

i ran FVD headers catless, side bypass and center bypass, was loud as all hell but it actually had more torque down low and up top power. I want to say it's mainly b/c of the headers more so than it being free flowing or it could have been b/c the car was 40-50lb lighter, or the combination of the two.

John Chan

Since I have DMS header on my 3.6 engine, I don't down shift from 6th to 5th as often on highway cruising. Much more friendly for street driving.
I used to have a 997S and I love the 3.8 low end torque for daily use.
I paid for the noise control, drivability in town and performance on the track. For the stock center durability, will see in the next couple years. Not my concern at this stage.

Jamie@dundonmotorsports

Also DMS is 321SS, most all other makers are 304SS. And unless others use a valve and stock muffler you'll have drone.

tgil

For stock set up except side muffler delete pipes, do you guys recommend valved or unvalved?

Do the valved delete pipes make the annoying closed and open sound as you increase RPM s like the stock side muffler set up?

Jamie@dundonmotorsports

The valved sides for our system are very inconspicuous as they open and close with the button off. Makes the system very street friendly!

hs63gt3

Question to ppl who installed raceheaders:
How did you guys deal with check engine light??
Extended O2 sensor??
If so, where can I get it?
Thanks in advance!

Jamie@dundonmotorsports

The Dundon Race Headers comes with an integrated post cat O2 solution that prevents CEL issues 90-95% of the time...