Jimmy-D

Dundon has been a great contributor on both the GT3 and GT4 forums which I frequent. They appear to make high quality products and stand behind the products they promote.

But - I have no problem with a third party validating the numbers they promote behind their products. They certainly charge more than other Vendors for their products which I am certain they are basing off the materials used and the numbers they are claiming. So- I hope this is all cleared up quickly. Have the numbers been validated on their GT3 race headers? I do not know the answer but if they have than my expectation is they will be for the GT4

Rick DeMan

This is good news!!
That should be good comparison, I would assume none of the cars have a flash?

KareemGT4

Nope no flash. Just all 3 with bmc filters.

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sunnyr

^Try make it a blind test... no chance of any unconscious bias.

CAlexio

But isn't the whole point of a dyno test to get objective data, and not subjective butt or ear dyno skew? How can unconscious bias be introduced when we are reading a graph which clearly shows that these headers offer similar performance gains to the other manufacturers?

And regarding DeMann, they don't sell headers.. they have no dog in the fight? They took the time to independently test equipment and posted the results.. seems pointless to implicate them as a biased party when they did a completely selfless act. Why is it hard to accept that dundon may have inadvertently goofed either with their baseline stock read or with their modified one and the real numbers are nowhere close to what was advertised?. Sometimes you just have to call a spade a spade..

Alan C.

Deman does sell performance upgrades. Who makes the best and most cost effective mousetrap at a price point?

Bardman

This. Particularly in light of the new cams and other enhancements Dundon are looking at for the GT3. I think its fair to say these companies are becoming (if not already) competitors of each other.

It is indeed possible that they somehow messed up here, but at this stage I personally am still prepared to keep an open mind. This is based on the results they achieved with the GT3 as well as the obvious R+D involved in developing the four pipe design.

This next test should be interesting, and I am also interested to see Dundon's response (which from memory was going to take some time).

Rick DeMan

Once again, I want to say this is a good thing to happen here. A few thoughts, for all to consider.

The type of Dyno being used and ACTUAL high HP numbers are NOT the point of this test and completely irrelevant.
So any statements or questioning the results about actual high HP numbers should be put to bed before it comes to the board. All Dynoes read different and should be used for evaluation purposes using before and after modification testing.

What we are looking for is the Delta between the Stock car to the cars with headers.

If the stock car makes 350 to the wheels [actual TBD] and manufacturers claims hold up then the results should look like this, using an guestimate base of 350 HP

Cargraphic claims 16HP
Dundon claims 41HP

Stock 350HP
Cargraphic 366HP
Dundon 391HP

Thanks to all spending their time and energy on this.

Nick Yoskin

Well this surely isn't positive 4 Dundon. Once more GT4 equipped with their headers hit the dynos the truth will be told. I hope their sake that their claimed numbers stand true because if they don't they will exit the market as fast as they entered the market.

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bhk1004

this is actually one of their main issues. They posted 41 hp gains... and you are interpreting exactly like everyone else. 41hp peak power gains. It's actually just the largest gain across the power band. Their peak power gain is actually around the same as everyone else. And that near redline 41hp gain hasn't been able to be replicated yet... not even by dundon themselves. Will they in the future? Maybe. Who knows. Hope so.

What's going on... who knows. I actually want to see the curves between the 2 header cars overlayed. My question is, is dundon really the strongest at redline like the initial dynos they posted? At least this will show how they seem to look against 1 other set on the same day.

mainly kind of annoyed it feels like their initial "marketing" hype of 41hp was a deception to start with. But yah let's see where it goes.

Jamie@dundonmotorsports

Nothing in life is a selfless act. There is always a motivation for behavior just have to look close enough or long enough.

Both of the customers that were there for installs or dyno's of Dundon products were talked to about Fabspeed headers and about DeMan custom headers that they make.

DeMan also makes a 4.0L kit that compete for the same dollars as other performance mods.

We are not beyond mistakes, but we have tested these headers over and over and over on our own dyno, the fact that the data isn't coming on others was a surprise, but we're working the problem.

I can tell you this, running more cars the same way on the same dyno isn't going to shed new light onto why...


Thanks guys, and yes we are competing with DeMan and BGB and others for the same pool of modification moneys. Our GT4 4.0L-4.2L crank, rods, pistons, cams, etc. are in finishing up designs so we'll be bringing that out as we get time...

There's isn't a reason for our car to make the gains and others not, as I've continued to say if the car is the same and the headers are the same, the only thing left is method, and we'll spend the time to understand the method differences as these cars are sensitive both with basic fueling adaptations and how they deal with emissions compliance and it's effect on performance.


Here's what we claimed: it's right from the front page and we're not doing any marketing BS that we're being accused of..

3600 RPM: +42 wtq
5000 RPM: +36 wtq, +34whp
5800 RPM: +15 wtq, +16whp
6500 RPM: +28whp
7000 RPM: +30whp
7500 RPM: +41whp

We saw 41whp at 7500rpm on our shop car, not at 6500rpm, seems all this talk of peak power and 40whp has everyone confused...


We tested MQANDIL's car from a few pages ago and made 40whp with air filters at ~7300, and according to MQANDIL's it's making more than this after his drive home. Unfortunately he had a family emergency on the day he was supposed to come back and hasn't been able to make it back for more dyno's to satiate all of you.


Family always trumps cars and I hope you all agree.

Here's the dyno since you some of you seem to have forgotten.


40whp gains


MQANDIL's Results
3600 +48wtq
6300 +20whp
7300 +40whp


So everyone, slow your roll, the headers do provide what we say they do and if you would give us a chance to get the data together we will prove it once again...

The plan is to take our car to a dynojet dyno that we have done extensive work on with our 991 GT3 and our dyno matches it quite well, and do work there. Currently he's at Tokyo Auto Salon, so may take a few days to get over there.

We also discussed potential reasons why the performance hasn't been duplicated as the intake air temps (as measured by the car) were all quite a bit higher during Deman's dyno's than when we dyno (on average 30-40 degrees higher) and also variable from run to run. It's also curious why the dyno runs all cut off well before redline and our max gains... We will be doing more testing trying to duplicate the low numbers from Deman to understand both the environmental factors, dyno factors and engine factors that may be causing this.

The onus is on us to provide this, and those that have seen our work so far know that we will get it done. We are in the midst of shop construction, finishing our other exhaust systems and working on cars, so not exactly sitting around doing nothing.

Stay tuned we'll get back to you...
Jamie

Bardman

Care to shed some more light on "Our GT4 4.0L-4.2L crank, rods, pistons, cams, etc. are in finishing up designs so we'll be bringing that out as we get time..." in another thread? Teaser to get the discussion going would be interesting.

CarAholic

Not to get off topic but are you still working on those intake mods you mentioned awhile back.

Rick DeMan

Jamie,

You can try to make this a personal thing if you like, but fact is there is no motivation to cause you any harm. I have spent my time and money to simply evaluate the product you make. I did not see the results you are claiming. Maybe I'm doing it wrong, Maybe I have flawed methods, But I can assure you, I have no agenda but to show what I found.

And secondly, DeMan does not make "custom headers" so we would never offer that. And honestly your statement is just a bunch of BS.
I showed MY customers results from other headers in comparison to yours. I did all this for free. I didn't try to sell them on anything.

So good luck with however this plays out.

And to the next guys running their GT4's on the Dyno, get ready for all the BS that follows when you try to simply show how it's doing. And for Jamies sake I sure hope somebody else's dyno with Dundon headers starts to look like the initial representation.

RealityGT

Rick, your reputation and word travels very far my friend...
Hello from north of the border,