gmgracing

The 991 GT3 is very sensitive to wheel speed and it must be dyno'd in AWD mode otherwise the car shuts its self down.

Even with the driver aids turned off the car will still shut its self down.

chinaman247

Are there any old dyno test on the .1 gt3?

Serge944

The dyno sheet shouldn't come as a surprise since high flow cats have been making hp on every GT3 since the 996. This is really the only substantial hp increase possible across the engine speed range on a gt3 without increasing displacement.

Anyways, per the dyno, the car made 105% of the baseline hp, which translates to a peak 24hp gain. How does nearly 500hp sound?

kyrocks

https://rennlist.com/forums/997-gt2-...s-headers.html

ShakeNBake

Do the 991 header cause CELs like the 997 headers from GMG? Pretty crazy that GMG does not stand behind the product.

RINGMEISTER27

Could you elaborate on this?? As far as I know GMG have always put out products of great quality.

ShakeNBake

I have yet to hear of anyone who did not have CEL issues without a tune to turn it off. They work fine (a bit up top at the expense of mids with OEM tune), but annoying and inconvenient to get a state inspection. GMG does not have a solve nor will replace cats for people who have trouble with it.

SamFromTX

Good to know that and sorry about your trouble, KY. I would want someone who stands behing their product, even if after warranty expires. Thanks for posting because I WAS considering them.

gmgracing

To Ky and Rennlist Members,

First off, GMG truly appreciates these forums as they give the enthusiast an outlet to share ideas, upgrades, questions, etc as well as vendors being able to showcase their products and services.

Secondarily, I know that if anyone has a specific issue they have with our products or services, James Sofronas, the President of GMG, has never shied away from any inquiries, questions, problems or concerns from any of our customers.

In this particular case, it's a bit frustrating that all the facts have not been properly presented in this case when we sincerely tried very hard to resolve Ky's issues.

These are the facts as we understand it:

Ky clearly states that he has 2500 miles of track use on the parts. No manufacture including PCNA or PMNA warranties any parts that are used under motorsport conditions.

In fact, 2500 miles of track use is more than the mileage driven by this year racing overall winning entry : http://en.wikipedia.org/wiki/24_Hour...973-present.29 a

PMNA made all the ALMS GTC Cup cars replace their cats after each year as they recommend replacement after 60 hours. After a race distance of 2500 miles these cars are completely rebuilt.

Ky had several communications with us to resolve his issues. We offered to replace the catalyst at our cost to him of replacement cats, if he decided it he wanted to go this route. At no point was there ever a discussion of $2200.00. In fact what we offered was free labor to replace the catalyst and he would cover the cost of the core itself.

Documented in email correspondences, we have no idea where KY got the price of $2200 to replace the cats, can you share that with us?

From: KYRIACOS
Sent: Tuesday, January 14, 2014 12:32 PM
To: Fabryce Kutyba
Cc: James Sofronas; joe foster
Subject: Re: CEL

Cats are fine. I just need extenders. Please send me ASAP...Going to COTA feb 6.

Thanks.

KY

On Jan 14, 2014, at 2:11 PM, Fabryce Kutyba <fabryce@gmgracing.com> wrote:

Ky

We never warranty cats as they are a performance/motorsport item and NOT OEM parts.

The headers are warranted for workmanship " welds etc"

If the cats are bad meaning the core itself has fallen apart we offer a replacement service for the cost $1000.00. You would send us the headers and cats back and we can replace the cats for you. We do this at basically our cost for the catalyst.

If the core is ok you will most likely just need a secondary 02 spacer and we can send you those. They cost $30.00 each

I did speak with your Tech today and informed of this.

He was going to check the cats and get back to me.

Let me know once you have more info or have your tech call me.


If further clarification is needed I am more than happy to screen shot the email thread for your review.


We also informed him to have his Porsche technician check the catalyst to see if it was faulty, Ky respond in an email stating that it was in fact ok verified by his dealer.

At no point did we state that he needed to buy a completely new system for the full amount.

Furthermore, Ky omits the fact that we offered to install a secondary 02 sensor spacer for him at no cost. He agreed and sent the headers back to us, we installed these parts for him at no cost and sent the system back to him overnight shipping at no charge.

Extreme use under track condition will accelerate the wear of any part. For this reason no manufacture will warranty a part when it is used under track conditions. This includes PCNA, PMNA, Audi Customer Racing to name a few.

Under normal use our systems do not trigger the CEL light .

In closing we have always stood behind our products and continue to do so. Sometimes unique circumstances take place and we work through those issues, no one is perfect, but we try our best.

kyrocks

That $2200 is the price I was quoted from Park Place Porsche who talked to you - (Tuesday, March 11, 11:38 am) I added O2 extenders as per your suggestions since the "cats were supposedly fine". Not only did I buy those overpriced extenders, they didn't solve the issue. Well, that didn't work. Look at the date of that email...this happened after that. I brought the car in to Park Place again since the CEL was on. The technician (S.T.) spoke with GMG and quoted me that price. If you read the email you posted, you suggested that the dealer talk to you instead of me, which is totally fine, because it is less headache for me.

Bottom line: This is not a post on how much GMG sucks. People can experience that themselves. I just want to sell these headers. I didn't realize it would blow up into such a GMG rant.

Mooty is right. I've learned. No need for ECU tune, headers, exhaust, etc... Porsche does a great job themselves.

By the way, search GMG on this forum. How many times have they defended themselves? Forget what I have to say.

This is a good price for good performing headers.

kyrocks

Sam, I am not telling you to avoid GMG. It is up to you to search the forum and talk to others (both positive and negative experiences) and make your own decision.

RINGMEISTER27

Popcorn time.

gmgracing

Ky,

Regardless of what Park Place wanted to charge you, we have told you in writing 2 months earlier that we will replace your worn catalysts at cost, no charge for labor, for $1000.

kyrocks

Thanks, Fabryce.

ayousef

I do have a small problem with the dyno numbers. Dyno's measure torque and RPM and calculate HP accordingly, the RPM values are completely bogus on the dyno sheet you have posted, which translates to incorrect HP figures. I understand this is an AWD dyno and the car is RWD but this has nothing to do with the RPM signal. I would be hesitant to even look at the torque numbers.

On the other hand are those numbers with the headers only or with the rear muffler bypass as well?

Same question for this video you posted on youtube, is this how the car sounds like with the muffler bypass only, headers only or both?

Thanks.