40whp and 30wtq gains with Dundon Motorsports Headers, no flash required!
#62
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#67
I recommend setting aside 3-4hrs realistically. I don't think it takes that long but if you have to use jack stands or ramps and such it may take longer. It's pretty straight forward. Taking the stock exhaust off probably takes the longest.
#68
3-4hrs max should be fine, that's including 30mins. to 1hr. of cooling down the engine. It's very simple to be honest.. And everything fits perfectly! Better if they use a lifter, a lot easier and you don't really need to remove the bumper. Enjoy! You're gonna be smiling going out of the dealer that's for sure
#69
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One thing to keep in mind.
Grey wire o2 sensor goes in the long bung
Blue wire o2 sensor goes in the short bung
(thanks 911_RS for the pic)
Grey wire (post cat O2 sensor) goes in the long bung. Blue wire (pre cat O2 sensor) goes in the short bung
Grey wire o2 sensor goes in the long bung
Blue wire o2 sensor goes in the short bung
(thanks 911_RS for the pic)
Grey wire (post cat O2 sensor) goes in the long bung. Blue wire (pre cat O2 sensor) goes in the short bung
Last edited by Jamie@dundonmotorsports; 03-25-2016 at 04:29 PM.
#71
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From: Gig Harbor, Wa
Dundon 991 GT3 200CPSI Catted Exhaust Dyno Results
We'll post up the pretty dyno sheets later tonight.
30whp max gain
27whp peak gain
424whp peak on our dyno (race system was 430whp)
30 wtq gain at 4200rpm
about 5-7hp loss over stock between 5200-6000rpm due to the extra volume of the system, we think we can get it back with a tune by altering the cam timing a bit in this area.
We'll have the car on the dyno tuning it next Wednesday.
Overall pretty happy with 200CPSI Euro Stage 5 cats in there, meets emissions, sounds good, makes 30whp!
30whp max gain
27whp peak gain
424whp peak on our dyno (race system was 430whp)
30 wtq gain at 4200rpm
about 5-7hp loss over stock between 5200-6000rpm due to the extra volume of the system, we think we can get it back with a tune by altering the cam timing a bit in this area.
We'll have the car on the dyno tuning it next Wednesday.
Overall pretty happy with 200CPSI Euro Stage 5 cats in there, meets emissions, sounds good, makes 30whp!
#72
We'll post up the pretty dyno sheets later tonight. 30whp max gain 27whp peak gain 424whp peak on our dyno (race system was 430whp) 30 wtq gain at 4200rpm about 5-7hp loss over stock between 5200-6000rpm due to the extra volume of the system, we think we can get it back with a tune by altering the cam timing a bit in this area. We'll have the car on the dyno tuning it next Wednesday. Overall pretty happy with 200CPSI Euro Stage 5 cats in there, meets emissions, sounds good, makes 30whp!
#73
Ok, so here is the preliminary results. This is DMS CAT1 if i call it that. This is the first varriant of this exhaust with 200 cell cats. It is doing well but i think it can be better! Yes you can see the gains are there, and the slight loss at 5-6000 is due to the added length required to fit the cats in there and keep the headers CLOSE to the same dimensions as the race exhaust. After todays dyno I learned some more stuff and got some more ideas and things to try out. SO with that being said Wednesday we are going to do a full FULL tune on the RH exhaust and the current catted exhaust, then I may build another cat setup when i have time and head back to the dyno to compare. Really it depends on space more than anything as you run out of USEABLE room very fast in there.
anyways. Here are the sheets STOCK to CAT exhaust and then another STOCK ex CAT ex and RACE ex.
anyways. Here are the sheets STOCK to CAT exhaust and then another STOCK ex CAT ex and RACE ex.
#74
Beautiful work
You deserve compliments not only for your work but for the way you are interacting with the forums showing the good and the less good of your product.
Many brands would not be transparent or look for improvement on the finished product as you are doing.
The customers that are interested in performance and quality will notice that difference.
Back to the exhaust I am really curious to see what can be done with the next tune or other exhaust modification.
The 27 peak horse power are already really good considering the cats
but of course it would be great if you could get back that slight loss in middle range.
I just tried different exhaust setup on a 430 scuderia on a dynaflow dyno with manifolds straight pipes and silencer and then with the same manifolds but std cats and a very basic xpipe.
The top power was almost the same but the torque and midrange power was less with the std cats.
Everyone usually think that with cats you should get better midrange and less top end power but it looks that it s not like that at least on those modern sport cars.
You deserve compliments not only for your work but for the way you are interacting with the forums showing the good and the less good of your product.
Many brands would not be transparent or look for improvement on the finished product as you are doing.
The customers that are interested in performance and quality will notice that difference.
Back to the exhaust I am really curious to see what can be done with the next tune or other exhaust modification.
The 27 peak horse power are already really good considering the cats
but of course it would be great if you could get back that slight loss in middle range.
I just tried different exhaust setup on a 430 scuderia on a dynaflow dyno with manifolds straight pipes and silencer and then with the same manifolds but std cats and a very basic xpipe.
The top power was almost the same but the torque and midrange power was less with the std cats.
Everyone usually think that with cats you should get better midrange and less top end power but it looks that it s not like that at least on those modern sport cars.
#75
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From: Gig Harbor, Wa
Beautiful work
You deserve compliments not only for your work but for the way you are interacting with the forums showing the good and the less good of your product.
Many brands would not be transparent or look for improvement on the finished product as you are doing.
The customers that are interested in performance and quality will notice that difference.
Back to the exhaust I am really curious to see what can be done with the next tune or other exhaust modification.
The 27 peak horse power are already really good considering the cats
but of course it would be great if you could get back that slight loss in middle range.
I just tried different exhaust setup on a 430 scuderia on a dynaflow dyno with manifolds straight pipes and silencer and then with the same manifolds but std cats and a very basic xpipe.
The top power was almost the same but the torque and midrange power was less with the std cats.
Everyone usually think that with cats you should get better midrange and less top end power but it looks that it s not like that at least on those modern sport cars.
You deserve compliments not only for your work but for the way you are interacting with the forums showing the good and the less good of your product.
Many brands would not be transparent or look for improvement on the finished product as you are doing.
The customers that are interested in performance and quality will notice that difference.
Back to the exhaust I am really curious to see what can be done with the next tune or other exhaust modification.
The 27 peak horse power are already really good considering the cats
but of course it would be great if you could get back that slight loss in middle range.
I just tried different exhaust setup on a 430 scuderia on a dynaflow dyno with manifolds straight pipes and silencer and then with the same manifolds but std cats and a very basic xpipe.
The top power was almost the same but the torque and midrange power was less with the std cats.
Everyone usually think that with cats you should get better midrange and less top end power but it looks that it s not like that at least on those modern sport cars.
Thank you for the encouraging words! This is how we're trying to be different than others out there, we want to show the customers what is possible and what we've been able to do. We will have some tuning work done on Wednesday this coming week and as soon as Charles can find the time (a lot going on right now) he's going to work on a revision to the CAT1 system.
This is our process. Make it, test it, learn from it, refine the model, improve it and make the next. We do this with everything!