GT3 KSA

for those of you who don't know, i had a 2015 991.1 GT3 equipped with Akrapovic full system then switched to the dundon race headers and got better power, you can see the thread here https://rennlist.com/forums/991-gt3-...vic-setup.html

fast forward three years later, now i own a 2016 991.1 GT3 RS, from day 1 i put the dundon race headers on it and JCR center bypass... this setup sounded great to me while driving (no drone) and was very aggressive. However, from outside of the car it was very loud.. too loud if you get what i mean... my friend's all said your car sounds like a heavy modified mustang not that there is anything wrong with that but it was too loud for me and the car would just get too much attention from the loudness

i only noticed this when i let a friend take the car out for a rip while i was sitting at a coffee shop, at that moment i decided better to return the stock center muffler (until i order the black lifetime dundon center muffler), so since i was going to do this i said i might as well dyno this take videos and share results with all to see and luckily enough i had a friend come along with his stock 2016 991.1 GT3 RS to join in on the dyno

here is a run of Dundon + JCR combo


here is a run of Dundon on its own


now that the videos are done, let us share the results, first up is my friend's stock RS



i know it is not my car but at least we had a stock RS on the dyno to use as a baseline, next up is my car with the combo of JCR + Dundon (keep your eye on the graph)



Above shows some gains over stock RS and below 3 runs shows consistency



We removed the JCR and went back on the dyno without even driving it around, gave it a couple of dyno pulls then came the numbers



it just got better and better after each pull also notice the graph is much better than when i was running the combo together



Here you can see comparison between the combo set (highest HP pull) and the current setup (best 2 runs) along with graphs showing power advantage to dundon on its own and better power band in mid range to peak



If you compare my friend's stock RS numbers with the current setup on my car now (dundon + OEM center) you will see gains at peak of about 20 whp & 10 wtq

what matters to me is the DELTA and not the numbers per say these were done on a Mustang Dyno they are not all calibrated the same, so the point of bringing the stock RS was to do a baseline number and see the DELTA with the different setups

i would like to say that both companies make superior products and the quality / finishing is spot on, the two systems are not made to go together, each on their own has advantages depending what you are looking for

if you are looking tor a center bypass then i highly recommend JCR and if you are looking for long tube headers that delete the side mufflers then for sure you need to reach out to Dundon

bogey1

Thank you for sharing. Great thread. I am trying to figure out which way to go on my 2016RS. I know one thing for sure, it will include parts from the guys at Dundon.

flsupraguy

Thank you for sharing. It will be interesting to see dyno numbers comparing Dundon headers to the new JCR headers.

For what it's worth dundon headers on a 991.1rs bring the power close to a stock 991.2rs?

I cant wait till dundon releases their intake setup so we can get near 500hp on a 991.2rs

GT3 KSA

This thread i believe tested them take a look https://rennlist.com/forums/showthre...1126597&page=8

Jamie@dundonmotorsports

On our dyno, Race headers get a 991.1 RS to about 450whp. a 991.2 RS stock is 465-468whp. So still a bit of delta there... The 991 RS intake combo is released for early adopters. We're instrumenting my car (I know, takes forever during track season to get time on the lift!) to demonstrate the pressure differences with the Dual Cone Airbox and 93mm TB combo on my 991.2 RS, the pressures will be similar on a 991.1RS. We saw static air (not moving air) gains on our dyno for the 991.2RS, so far the data has been clean on the 991.1 RS (cold stock runs, then really warm afternoon temps confounding the data a bit). So getting the data while the car is moving is important...

We're at 492whp on the 991.2 RS as the current watermark, the new "Crack" pipe Megaphone Center Delete may help push it up a bit so 500whp isn't far away...

dxbtousa

Nice info and numbers mate - thanks for sharing.

GT3 KSA

happy to help and you are all welcome

GT3 KSA

dundon (black) center muffler with tips arrived earlier today

i decided to weigh the DMS muffler vs. the stock RS muffler ~ difference is 7 kgs



DMS muffler above & stock .1 RS muffler below



JCR super light tips can't be installed on the muffler that arrived today, i decided to weigh the tips ~ difference is 250 grams



JCR super light tips above & dundon tips below



should be installed later today

JCR-Porsche

The scales are off a good amount on the smaller measurements, our Superlight Tips are 0.46kg and the OEM Titanium Centre is 5.54kg

JC

GT3 KSA

Noted that the scale is off my bad thanks for the info

i assume though the delta would be the same either way the super light tips don't fit the new muffler

kaboobie

FYI: I have a 911.1RS Dundon orange muffler and D race headers and tune. The other day I was fortunate to drive two cars on the track for a few laps each. A 991.2RS with Dundon black muffler, D catted headers and tune and a completely stock 991.2RS. I was quite surprised that my car was noticeably faster than the stock 991.2RS. The owner even thought my car was faster to the point that after driving my car he wanted to immediately mod his car. The other car with black muffler, catted headers and tune were I'd say was like a step faster like mine was to the stock gen2. I thought the difference were a lot and the the stock gen2 would be faster than my car but that was not the case and after the tune the difference is not as bad as I thought.

GT3 KSA

the great thing about doing dundon headers & muffler to my knowledge is that a tune is not required

having said that who did your tune?

kaboobie

Hi GT3KSA,

While my car did not show any lights before the tune, after the tune the response was much better, and it is livelier in the lower RPM range. (below 4000). I had Autowerks who is a subsidiary/partner (not too sure of the arrangement) of McChip in Thailand did it. The other .2RS also had it done there.

https://mcchip-dkr.com/en/chiptuning...=carselector#0

I have the dyno before and after the tune in my car. I'll take a pic for you if you want to see it.

GT3 KSA

please do share

always interested to see before / after dyno results

kaboobie

This is before and after tune. The base line has race headers, air filter, and orange muffler installed. As you know please just look at the differential.