So I was able to take my GT4 out for a test drive after the latest upgrades were recently completed. They consisted of the following:

Dundon street headers
BMC air filters
NineMeister lightweight flywheel and clutch
Michelin Sport Cup 2 R’s
Track focused alignment.


All I have to say is that this is how the car should have come from the factory. It sounds GLORIOUS. No drone at all. I love the way it just comes to life above 4k rpm. I did everything at once so I cannot say which parts did what, but my overall impression is that the car is faster with better throttle response.

No issues at all with the clutch or flywheel. The travel of the pedal itself feels much smoother, it almost feels longer but it doesn’t bother me in the least. It engages immediately and accurately. Very pleased with it and love the new found responsiveness.

The biggest surprise though is how raw the car feels overall now. Little vibrations here and there that were not there before. Gives it (or at least me) the feel of a true GT car. I absolutely love it. The new alignment has given it a spring in its step that it didn’t have before. I’m looking forward to giving it a proper drive.

Now, for what I really came here to say. I need to thank each vendor that I engaged with when I was doing my research. Everyone, and I mean everyone was an absolute pleasure to deal with. Knowledgeable and never pushy. They never hesitated to answer my questions and I had a number of great car conversations with them. I only wish I could have done business with all of you. @Soul Performance @Fabspeed Motorsport @M Engineering @Jamie@dundonmotorsports @Softronic @NineMeister

My apologies for not listing any others that I missed.

I would also like to thank many in this community who posted on many of the related topics that I researched. I thoroughly enjoyed learning new things along the way while being entertained with some of the spirited discussions on exhausts. I would especially like to call out @gordotre for taking me for a ride to hear his setup in person and @nothingman for starting me down the whole exhaust rat hole when I heard his GT4 on the track at a HPDE day.

And last but not least I need to thank @PaEuros . I met one of the owners last year at an event at VIR last year. A few months later he opened a shop in Exton PA right when I was looking for an independent mechanic to help me with some maintenance needs, I had no idea that he was even doing this. Absolutely fabulous service and the entire place is staffed with people who truly appreciate these vehicles.

Now back to waiting for winter to end…….

 

Sounds great in the vid. Still going to do a tune?

 

He already got the best 'tune' you can get for the GT4 . . . Dundon headers/OAPs

Avera

 

When you say a 'track focused alignment' I am wondering what mods you did to get such an alignment? (e.g., aftermarket rear toe links?)

I had my GT4 aligned at dealerships to maximum factory 'approved' negative camber with all OEM parts. The OEM rear toe links are limiting factor and I do not think many on this forum would consider it 'track focused.'

That said, for my daily driving needs and spirited excursions, the GT4 handles like a dream on the roadways. If I had the ability/interest to push the car to its limits on a track I suspect some rear toe links and 'track focused alignment' might be desirable.

With respect to the Dundon headers/OAPs, well, they are hard to beat. If you like things quiet until the valves fly open, then you are all set. Personally, I could not stand the quiet at lower RPMs when valves are closed, then the abrupt scream when the valves fly open. Holding the valves open with valve shaft collars was the cure.

Avera

 

@Avera I haven't done any modes yet to the suspension. When I say track focused I am implying more of an aggressive alignment than what the dealer would have done with a stock suspension (basically the same as what you did at your dealer). I did this mainly because the biggest limiting factor for that car on the track at this time is me. It is a definite possibility in the future but I don't believe in doing things just to do them unless I can realize the benefit of such a modification. I need to get more comfortable pushing this car on the track in a safe manner first.

@IndigoInkTaco no tune is necessary with this current configuration. I do not think I could justify the cost for one right now as I do not think I would be able to notice the difference. If this were a turbo it would have been done.

 

I did my suspension parts and alignment all at once; it completely changed the feel of the car, in a good way. My mods were: tarret monoball inners, clubsport camber plates, tarett solid thrust bushings, TCP rear toe links, tarett front tie rods, track focused alignment as detailed in the alignment thread. Stock ride height. Note: many will disagree with how I like a bit of toe-out in front.

If I had to pare down my list of mods to the most effective, it'd be the Dundon Headers and the above alignment updates.

 

@SANSPDK Will be interested to hear more about how you get on with the LWFW + Clutch. I have one sat on my shelf.

@enduro - I run a little bit of Toe-out on the front also - so you are not alone!

 

@SANSPDK Good to know I’ll have a local GT4 to keep me company.

I will be taking delivery of MY 23 within the next month or two, and I also plan to move out of the city to Bucks County by summers end.
See you out there!

 

What is the difference between the Cup2 tires that come stock vs Cup@ R tires?

Avera

 

Cup2 R are pretty nuts. Very sticky, but very short lived and very pricey. For a my GT4, I'll be trying SC3R when they come back into stock, and comparing with a set of RT660 on my other set of track wheels.

 

@SANSPDK , these types of threads are EXCELLENT for the forum / community. Great consolidated format, and cool of you to give thanks to all those who helped along the way.

I have an inbound CGTS, and could use your input on a few items that will help me sort my plan:

• Is your exhaust ONLY the Dundon street headers with their OAP--and you are still running the factory back box?
• Do you have a rough guess of what HP gain you likely got with the exhaust changes alone?
• In regard to the 'little vibrations' is that attributable to the exhaust changes--and in particular a nuisance OR was your description more about characterizing the car as 'coming alive'?
• Similar to @TDT 's question, I look forward to reading more about your experience with the LWFW / Clutch changes. To that point, would you say of all the changes you made that one 'might' be the least critical in making the car come alive for you?

Most importantly, so cool you are enjoying the car--and what a great summary to read---'this is how it SHOULD have come from the factory.

 

@Bearrun21 In answer to your questions.

- Yes, only the Dundon street headers and OAP. I still have the factory back box
- If I was to take a guess (and this is an absolute shot in the dark) I would say 30'ish
- I would attribute the vibrations to the exhaust and I was referring to it coming alive. It wasn't anything that indicated a loose panel or anything, it was more of 'drive me already I have power to unleash'
- I would say the LWFW/Clutch would be more complimentary in terms of how I am stating the car is coming alive. It was only a short test drive but I can definitely tell you the engine revs much faster and feels more responsive and my understanding is that is a direct result of that modification.

 

Avera, There were a few reasons why I went with the R's over the regular Cup 2's.

1. There was only a 200 price difference between the two for a complete set
2. There was a 9% price increase from Michelin that went into effect Jan 1
3. (and this is really the biggest one) The R's were in stock

My understanding is that they are even more track focused and will wear faster than the Cup 2's. My car originally had the Dunlops on them. While they were an OK tire I am more than ready to try something else. They really turned into hard pencil erasers at the end of last season.

 

@SANSPDK Can you capture some video/audio of the car at idle… inside and outside… just want to hear how the engine turns over with LWFW in place, and then some throttle blips.. to get a perception of the response?

 

OP. Glad you are happier with the car, you are heading in the right direction. However you missed an opportunity by not getting the TPC adjustable rear toe links and throwing some shims on in the front to get a better alignment. Buying cup2R tires and not supporting them with a decent alignment is a bit of a waste. You said you think your skill should grow before you adjust the car further… but imagine if the car became less vague and more predictable how much quicker your confidence and skill would grow? As Tom at TPC Racing told me when I first got my GT4 2 years ago - traction is traction and more is always better. Good luck!