When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Can't wait to see DeMann's results.. these guys are so well-respected in industry and should account for all variables. Specifically, i hope to see and think it's important to verify:
-a direct graph overlay of stock vs with Dundon headers
-using the best stock run with best Dundon run - there can be a variation between runs of 5hp or more.. so using the worst stock run with best modified run could show a bigger difference.
-everything dynoed same day with same humidity etc.
-all other things being equal such as fans, filters etc.
This is such a delicate game.. congrats to all who are brave enough to undertake it both on the manufacturing side and on the testing side. Opening yourself to forums with this level of scrutiny can't be easy. I think we're lucky to have super quality suppliers like cargrafix, fabspeed and now dundon producing awesome parts for our cars.
Were the supplied air filters installed? No, car had BMC filters.
Any more runs than 1 post? Yes, those were the best ones which they sent me.
Air directed into the side air intakes? Yes, they're going to send me vids, but the pics I saw confirmed this.
Was sport on, etc? Any CobbAP logs taken during the runs? Sport was on, they didn't do logs.
Also can you have them send us the DynoJet DRF files? I will ask Botthoff.
I haven't driven the car yet, I like the fact the dips at 3.5k and 5k appears to have smoothed quite a bit, can't wait to experience it!
Also were the K&N airfilters that we supplied used? In our testing the stock airfilters are quite a restriction especially after the headers were added. Performance mods are all about eliminating the next restriction and our headers identified the air filters to be a big one.. That's why we included them free with all of our header systems...
That's quite interesting... a lot of people (stock and with mods) have tested filters and posted here that gains have been almost nothing. Myself have decided to stay OEM air filter because of this. Now I wonder if I should test some BMC or K&N.....
That's quite interesting... a lot of people (stock and with mods) have tested filters and posted here that gains have been almost nothing. Myself have decided to stay OEM air filter because of this. Now I wonder if I should test some BMC or K&N.....
When faced with conflicted or different data we do what we do and start testing. Luckily we had a customer in today for an install (MQandil from the board). We confirmed some things we already knew to be true and learned some new things.
1. The K&N airfilters on a stock car do very little. When you add headers that are pulling more air from the intake the stock airfilters are quite a bottle neck, 10-15whp in fact, we'll post the data after I take a look at it tomorrow
2. An OEM Porsche tune and a Cobb Stage 0 (supposed to be stock tune) are the same with the factory headers and cats on the car and even K&N airfilters. They are not the same with Dundon Race headers and high flow filters on the car.
So we have a path to understand some of the data we saw today and what we have already published. I'll get it together and share with everyone...
It's both interesting and some of it surprising...
When faced with conflicted or different data we do what we do and start testing. Luckily we had a customer in today for an install (MQandil from the board). We confirmed some things we already knew to be true and learned some new things.
1. The K&N airfilters on a stock car do very little. When you add headers that are pulling more air from the intake the stock airfilters are quite a bottle neck, 10-15whp in fact, we'll post the data after I take a look at it tomorrow
2. An OEM Porsche tune and a Cobb Stage 0 (supposed to be stock tune) are the same with the factory headers and cats on the car. They are not the same with Dundon Race headers on the car.
So we have a path to understand some of the data we saw today and what we have already published. I'll get it together and share with everyone...
It's both interesting and some of it surprising...
Thanks for the info Jamie.....could it be that OEMs loose flow pretty quick or is it just that they are way more restrictive than the aftermarket options? Also, I think you mentioned that testing the IPD + TB also didn't provide much gains....but the filters do......is there a reason for this? Thanks for sharing what you have found.
Can't wait to see DeMann's results.. these guys are so well-respected in industry and should account for all variables. Specifically, i hope to see and think it's important to verify:
-a direct graph overlay of stock vs with Dundon headers
-using the best stock run with best Dundon run - there can be a variation between runs of 5hp or more.. so using the worst stock run with best modified run could show a bigger difference.
-everything dynoed same day with same humidity etc.
-all other things being equal such as fans, filters etc.
This is such a delicate game.. congrats to all who are brave enough to undertake it both on the manufacturing side and on the testing side. Opening yourself to forums with this level of scrutiny can't be easy. I think we're lucky to have super quality suppliers like cargrafix, fabspeed and now dundon producing awesome parts for our cars.
If you read my testing results, ALL the numbers stated were the BEST numbers from each test session.
The entire test was completed in a 3 hour time period.
Fans, cooling, test procedures are the best possible.
All dyno results will be posted shortly.
__________________
2016 GT4-R
Rick DeMan
DeMan Motorsport
Upper Nyack, NY
845 727 3070
Porsche Sales & Service
Porsche Race services and parts www.DeManMotorsport.com
Thanks for the testing Rick and doing this for the community.
Was there any range in the stock runs, or were all 6 stock runs 362whp? I understand other cars you've run had variation. Any data logs of the stock runs? Stock Dyno sheet with all 6 runs
If you can send us the Dynapack run files we can compare to our runs this would be helpful to the community as well
Also were the K&N airfilters that we supplied used? In our testing the stock airfilters are quite a restriction especially after the headers were added. Performance mods are all about eliminating the next restriction and our headers identified the air filters to be a big one.. That's why we included them free with all of our header systems... This quote from your Original Post states STOCK car and has no mention of air filters. We conducted our test the EXACT same way as yours on the same Dyno. "Hi All,
We're very happy and humbled by the response we've received from the forum members on our development work for the GT4 so far. We've finished up the development and production prototypes. Just tested them on the car this morning.
Here's the results on a stock car, bolt on, no tune."
Were any additional fans directed to the air intakes as in our testing the air box get's heatsoaked pretty quickly, and the ecu is quite picky about intake air temps (ambient temps and SAE correction don't really account for it).
Was the hot air coming out from radiators blocked from getting into the air intakes? Fans to the intakes, fans to the rads and hot air blocked. I have owned my Dynapac Dyno for 18 Years, have done over 6000 runs on Every kind of Porsche imaginable from a 906 to a GT1. Its not my first rodeo.
Your dyno reads a stock car much higher than ours, we see 334-338whp peak power from a stock GT4, and it rolls off after that... I think this is the difference between a dynapack 3000 and a dynapack4000.
Our end results meaning Top HP numbers are the same. These Dynos use the same components. I am going to suggest YOUR base line numbers are Very low making a big Delta to the end number. Even if your base line numbers are correct and the Delta to your finish numbers are correct then MY base line to My finish numbers should have the same Delta. But as you can see one end of OUR collective data lines up, just the starting point does not.
Jamie
Dyno Sheets for everybody to consider.
Headers Only
Headers with Dundon Tune
This sheet is a comparison of the best stock run with the best Headers only run. Stock in Blue and Headers in Red
I hope this info helps anybody interested in this thread.
Our collective intentions here are not to discredit anybodys work or product, simply a presentation of a test performed under controlled conditions establishing a baseline and result using a bolt on performance item. As we all know, actual numbers higher or lower from Dyno to Dyno are irrelevant when it comes to testing components. ONLY the gains/Delta is what we are looking for.
You can all make your own conclusions from the data presented here and by others testing the same product.
Last edited by Rick DeMan; 12-22-2016 at 02:34 PM.
Thanks for the info Jamie.....could it be that OEMs loose flow pretty quick or is it just that they are way more restrictive than the aftermarket options? Also, I think you mentioned that testing the IPD + TB also didn't provide much gains....but the filters do......is there a reason for this? Thanks for sharing what you have found.
It's the same reason the factory puts BMC filters in the GT3RS, there's a point where the filters won't flow any more and are a restriction. We found this quickly in our testing on the headers this is why we included them for free with all of our headers.
The plenum and TB we didn't see any delta, to us that means that isn't the next meaningful restricition or resonance multiplier...
I'll report a bit more of our testing with MQandil later today.
Because everybody is so curious about Dyno data, I have posted here a Dyno comparison between a DeMan Motorsport GT4 4.0L and the GT4 with Dundon Headers.
DeMan 4.0L car has Carrera S throttle body STOCK AIR FILTERS, Fabspeed short tube headers, DeMan Motorsport Tune and of course our 4.0L stroker kit running on Street Gas with stock muffler.
Last edited by Rick DeMan; 12-22-2016 at 03:54 PM.
Am I missing something or are these numbers nowhere close to what dundon originally showed? Not trying to be negative but kind of have to talk about the emperor's clothes here. Looking back at the original dyno claims and looking here, I'm not even sure there is a truly desirable change from stock.. yes you get the torque bump in the midrange as with the other brands, but there is some significant dipping below the stock line as well which if I recall was not present with cargrafix or fabspeed. And the power claims are simply not there. What am I missing?
Its because the testing was done without the K&N high flow airfilters that we've been using since day 1.
i'll post up some testing we did in the last few days to try and duplicate these results and show what's missing... We have and can show the differences between what was shown by others and what people are feeling.
No deception no smoke and mirrors just data... the context of the data is key and deciphering it all is even more key.
Its because the testing was done without the K&N high flow airfilters that we've been using since day 1.
i'll post up some testing we did in the last few days to try and duplicate these results and show what's missing... We have and can show the differences between what was shown by others and what people are feeling.
No deception no smoke and mirrors just data... the context of the data is key and deciphering it all is even more key.
We've been transparent and will continue to be.
30-40+ whp due to air filter restriction seems pretty hard to believe...
12-21-2016, 07:49 PM
DeMann's results
