Jamie@dundonmotorsports

Hi Guys,

Just spent the weekend at the Smokies GT event and had lots of one on one time with owners and answering questions etc...

Ipse Dixit asked in another thread if we could do an open Q&A thread.

Few rules:
1. Let's keep in classy and non argumentative, we'll be respectful and we ask you all to be (Rennlist OG rules...)

2. Some questions we may not be able to answer and I'll do my best to get an answer that doesn't float into something we consider to be trade secret or a differentiator...

Beyond that, have at it... Will try to check in at least once a day!

TRAKCAR

What's your favorite beer?

MaxLTV

A classy question - is it possible to run catted Dundon headers on a GT3 and pass sound at Laguna with GPS module and turn-away pipes?

Jamie@dundonmotorsports

Anything Belgian, a nice Dunkleweissen when in Bavaria, but anymore my heart is with fine craft whisk(e)y. Scotch, Rye and Bourbon are all in the rotation

It is and we've recently had a customer do it. We're working on a replacement center muffler that reduces dB's about 10 or so over the stock center muffler. We're also having Alekshop test some muffled test pipes that go in place of the cats for track days. It's not great for the car to be under load with the flaps closed so we're trying to find solution for dB limited tracks without using gps flap control...

Buteo

Is it still possible to order a GT4 header- what would be the eta if so?

tonymission

Will I be able to shave a second off my lap time with catted headers at AMP?

Jamie@dundonmotorsports

Yes we plan on selling these forever! And we have 2 ready to ship this week and 2 more ready to ship next week.

If you can handle the extra power, absolutely!

ChrisF

Have you seen physical evidence of the finger follower issue in any of the RS G engines?

Jamie@dundonmotorsports

Great question. Short answer, no haven't personally seen or received evidence of one yet, but I have heard rumor of a few that have died in the fleets of track rental car companies in Europe. Is the G engine immune, unfortunately no. Coating everything (finger follower, cam lobe) in DLC will extend the amount of time until a lack of lubrication failure occurs, but it doesn't change the fact that there is no oil between the finger follower and the cam lobe. If it was immune, porsche wouldn't have gone to a solid lash adjuster in the 991.2...

You can check out the finger follower thread for more details, but our recommendation for owners is while the engine is under warranty, don't sweat it too much. Once the Engine Health Monitor is released (prototype boards arrived this week), you can get data on it to see that the engine is healthy and continues to be healthy.

jlennox

Do you have any additional GT4 development in the pipeline? If yes, can you comment on what?

MM3.9GT3

Jamie: Given that long tube headers build mid range, and high end power (when compared to stock) at the expense of low end power, why is there no drop off in low rpm power when compared to stock headers?

Jamie@dundonmotorsports

Quite a bit, everyone's favorite new track car is getting quite a bit of attention:

Things we're testing now on a Spyder Build we're doing.
991 GT3 Plenum and TB

Prototype Big Air filter box (less pressure drop)

X51 cams

X51 heads (they're a little different than stock GT4, and we're working on porting the stock heads to be better than X51)

Catted/non catted side pipes and high flow valved lower dB muffler (will work on any 981, and bolt to any race header)

The catted sides and muffler are going to select beta testers for feedback in the next few weeks, both local and extended Dundon family. The air box and 991 GT3 manifold adapters we're working on the tune on the Spyder and to ensure they are as efficacious as we expect.

On the engine side I spoke a bit at Smokies:
Phase 2 of the Spyder build is 4.5L bore and stroke. The fruit of this will allow us to easily make 4057cc (4.1L) engines with just a bore and big piston swap, 4167cc (4.2L) with stroker crank and new rods and 4.5L for the full meal deal. First parts are finishing design/mfg. These parts also apply to other 9A1's including the 991 GT3 and RS, but have to fix the valve train first...




Couple things with this. Low RPM gains are all from removal of restriction or reducing pressure in the exhaust track. Mid and upper RPM gains are all from pressure wave tuning. When done right, you have gains throughout the entire RPM range.

MM3.9GT3

Jamie: Thanks for the explanation.

jlennox

Wow - sounds like some very exciting stuff is coming for the GT4. Great news and I wish you the best of luck. Sorry for hijacking the tread in the GT3 forum. I read some talk about a multi link rear suspension package for the GT4. Oddly enough the mention the 4.5l too, are you also involved in the suspension development or do you know anything about this? Thanks!

Jamie@dundonmotorsports

Trebien and I trade PM's on occasion, I followed up on the multilink rear. The 4.5L I can tell you is happening, at least on our end...