Dundon 718 GT4RS Development Thread. Input wanted!
01-06-2023, 09:11 PM
#16
Burning Brakes
Not to worry....if they develop a muffler for the 4RS they should be able to develop the last section of the GT4 system (the one that splits into a Y) into a single exit/entry for the muffler.....everybody wins!
But it can also be the other way around, adapting the current GT4 design to the 4RS...the only difference between both OEM is in one the split happens before the muffler and on the 4RS it happens on the muffler.
Also the 4RS GPF looks smaller than on the GT4 and the secondary O2 sensor is on the OAP before the GPFs,kind of like the Dundon system.
But it can also be the other way around, adapting the current GT4 design to the 4RS...the only difference between both OEM is in one the split happens before the muffler and on the 4RS it happens on the muffler.
Also the 4RS GPF looks smaller than on the GT4 and the secondary O2 sensor is on the OAP before the GPFs,kind of like the Dundon system.
Will that be the case with the RS? My suspicion is yes.
Avera
01-06-2023, 09:13 PM
#17
Rennlist Member
I’ll do all the “packaging” R&D for free, along with shipping for the first allotments if a full header back system comes as compensation. Included would be all the tooling required on my end to customize all your corrugated/foam to protect the internal parts, and print plates for my presses to pump out your company logo on all exterior surfaces…. I call that a win-win!!! MY 23 GT4
01-06-2023, 09:22 PM
#18
Rennlist Member
To my knowledge, the only two rear box options that manage drone with high-flow headers/OAPs are the OEM and Akra rear boxes. The problem is neither produce that RSR tone. Seems decent tone comes from mixing the banks (X-pipe) but, unfortunately, mixing the banks is a recipe for drone in the GT4. In short, the better the tone, the worse the drone.
Will that be the case with the RS? My suspicion is yes.
Avera
Will that be the case with the RS? My suspicion is yes.
Avera
01-06-2023, 10:06 PM
#19
I love that you ask 4RS owners for what they want and you get a bunch of GT4 owners chiming in...
I found I can get a pretty good setup on the 4RS with stock suspension etc. However some more downforce would be good to bring it into line with the GT3, also exhaust to give it a power bump to come into line with the GT3 and sound better from outside too.
If the exhaust system can be good for RoW cars too, I'm in Australia so may have different sensors around the particulate filter.
I found I can get a pretty good setup on the 4RS with stock suspension etc. However some more downforce would be good to bring it into line with the GT3, also exhaust to give it a power bump to come into line with the GT3 and sound better from outside too.
If the exhaust system can be good for RoW cars too, I'm in Australia so may have different sensors around the particulate filter.
Last edited by cafe_racer; 01-06-2023 at 10:08 PM.
01-06-2023, 10:23 PM
#20
Rennlist Member
Over axle pipes to get rid of the GPF
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GT4RS maniac (01-09-2023)
01-06-2023, 10:49 PM
#21
Burning Brakes
I love that you ask 4RS owners for what they want and you get a bunch of GT4 owners chiming in...
I found I can get a pretty good setup on the 4RS with stock suspension etc. However some more downforce would be good to bring it into line with the GT3, also exhaust to give it a power bump to come into line with the GT3 and sound better from outside too.
If the exhaust system can be good for RoW cars too, I'm in Australia so may have different sensors around the particulate filter.
I found I can get a pretty good setup on the 4RS with stock suspension etc. However some more downforce would be good to bring it into line with the GT3, also exhaust to give it a power bump to come into line with the GT3 and sound better from outside too.
If the exhaust system can be good for RoW cars too, I'm in Australia so may have different sensors around the particulate filter.
Based on your 'wants' . . . it seems you want a GT3
Avera
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01-06-2023, 11:23 PM
#22
Instructor
01-06-2023, 11:50 PM
#23
You got me there! Jel of my mates 992 GT3 (external) sound and downforce, I swear its the only reason he's faster than me 
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Avera (01-07-2023)
01-07-2023, 12:46 AM
#24
Do an a-la-carte offering as follows...
1) Headers
2) OAP side pipes
3) Rear muffler
That way people can pick and choose which pieces they want to get. I would want the headers and OAP pipes and put those one with the oem rear muffler and get rid of those particulate filters.
1) Headers
2) OAP side pipes
3) Rear muffler
That way people can pick and choose which pieces they want to get. I would want the headers and OAP pipes and put those one with the oem rear muffler and get rid of those particulate filters.
01-07-2023, 01:35 AM
#25
Rennlist Member
Subbed to see how much juice chucky squeezes out of the motor with proper long tubes. To the gt4 crowd who already know what if needs, remember the gt4 didnt rev to 9 grand or have carbon brain tubes making 105dB in the cabin stock. The gt4 started as a hair dryer from the factory
01-07-2023, 01:59 AM
#26
Lots of expected comments from the GT4 owners 
We know you want the muffler badly, but I'll be honest, there's a reason no one else has done it. We have our original design for the GT4 (which has been tested, and sadly, doesn't turn a GT4 into an RSR). We will see what needs to be done to make a box that works for both the GT4 and GT4RS.
I'm also interested to hear from GT4RS owners as to what they would like improved on the platform.
We know you want the muffler badly, but I'll be honest, there's a reason no one else has done it. We have our original design for the GT4 (which has been tested, and sadly, doesn't turn a GT4 into an RSR). We will see what needs to be done to make a box that works for both the GT4 and GT4RS.I'm also interested to hear from GT4RS owners as to what they would like improved on the platform.
01-07-2023, 08:56 AM
#28
Burning Brakes
Do an a-la-carte offering as follows...
1) Headers
2) OAP side pipes
3) Rear muffler
That way people can pick and choose which pieces they want to get. I would want the headers and OAP pipes and put those one with the oem rear muffler and get rid of those particulate filters.
1) Headers
2) OAP side pipes
3) Rear muffler
That way people can pick and choose which pieces they want to get. I would want the headers and OAP pipes and put those one with the oem rear muffler and get rid of those particulate filters.
To my knowledge, no other aftermarket company makes their headers/OAPs mutually inclusive . . . and I have yet to hear an aftermarket offering that accomplishes what Dundon has accomplished. Although not talked about much, I do not think there is an aftermarket tune out there that comes close to producing the TQ/HP gains that Dundon achieved wither their headers/OAPs in the GT4?
Only Dundon knows what they will do, but I doubt they will alter their header/OAP approach for the RS?
I am also curious to see if Dundon can get some tone out of the RS rear box without the drone? @Ted@dundonmotorsports seems to be preparing us (both GT4 and RS owners) that a miracle is not forthcoming.
Avera
01-07-2023, 10:49 AM
#29
The rear muffler on the 4RS is the same as the GT4 with the exception of moving the path split to the muffler on the 4RS...…expect same sound.
Also, another vendor already confirmed that the internal passages of the 4RS muffler are smaller than the 992 GT3 while using the same engine with longer exhaust plumbing.
It's no secret that a muffler rear section on the GT4 produces power (not a lot) and we could assume that will be the same with the 4RS.
If a muffler is develop I'm pretty sure it can be used on both cars.....
The OEM manifold and OAP is a different arrangement from the GT4.
If you ask me to guess, we will have the same problems on the 4RS as on the GT4...of the 3 sections that can be swap, pick 2 or risk getting lots of drone and being too loud.
If there was a way to package a GT3 muffler internal design into the GT4/4RS step muffler design that would be great
Also, another vendor already confirmed that the internal passages of the 4RS muffler are smaller than the 992 GT3 while using the same engine with longer exhaust plumbing.
It's no secret that a muffler rear section on the GT4 produces power (not a lot) and we could assume that will be the same with the 4RS.
If a muffler is develop I'm pretty sure it can be used on both cars.....
The OEM manifold and OAP is a different arrangement from the GT4.
If you ask me to guess, we will have the same problems on the 4RS as on the GT4...of the 3 sections that can be swap, pick 2 or risk getting lots of drone and being too loud.
If there was a way to package a GT3 muffler internal design into the GT4/4RS step muffler design that would be great
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01-07-2023, 10:57 AM
#30
The rear muffler on the 4RS is the same as the GT4 with the exception of moving the path split to the muffler on the 4RS...…expect same sound.
Also, another vendor already confirmed that the internal passages of the 4RS muffler are smaller than the 992 GT3 while using the same engine with longer exhaust plumbing.
It's no secret that a muffler rear section on the GT4 produces power (not a lot) and we could assume that will be the same with the 4RS.
If a muffler is develop I'm pretty sure it can be used on both cars.....
The OEM manifold and OAP is a different arrangement from the GT4.
If you ask me to guess, we will have the same problems on the 4RS as on the GT4...of the 3 sections that can be swap, pick 2 or risk getting lots of drone and being too loud.
Also, another vendor already confirmed that the internal passages of the 4RS muffler are smaller than the 992 GT3 while using the same engine with longer exhaust plumbing.
It's no secret that a muffler rear section on the GT4 produces power (not a lot) and we could assume that will be the same with the 4RS.
If a muffler is develop I'm pretty sure it can be used on both cars.....
The OEM manifold and OAP is a different arrangement from the GT4.
If you ask me to guess, we will have the same problems on the 4RS as on the GT4...of the 3 sections that can be swap, pick 2 or risk getting lots of drone and being too loud.