Hi,

I know you wrote one million times about the above...

I am considering to upgrade my gt3 mk1 on a bit stiffer level, I have already got rear toe steer kit (from RSS) and nothing else

I am in doubt between sub frame bushings, LCA uniballs (end + thrust arm bushing) and dogbones

don't want a TOO MUCH stiff car (driving on a road a bit as well) and therefore I am worried about putting all of them and let the car become a cup...

handling is actually very good, but a bit "floaty"

think to start with sub frame bushings (that I tried a few years ago on a Carrera S mk1 and work extremely well) but not sure if leave just with that, or maybe include a LCA monoball end, or maybe dogbones instead

or better forget sub frame bushings and go for the rest of the stuff ? (my intuition tells me sub frame bushings could do a more effective job than uniballs, but it's just my perception... not supported by facts)

which is - on your opinion - the best for a good compromise in order to reduce the floaty feeling without going beyond the limit of a decent confortable driving ?

thank you in advance

 

Hi

You are probably now where I was 1 year ago.

Here is the short way to do this:

- Toe steer kit (done)
- Dog bones
- Rear motorsport Lower Control Arms (solid bushings)
- Front (you have a choice), either motorsport Lower Control Arm (which has rubber bushes) or RSS Tarmac Series LCA (which has solid bushes). I have the RSS

You don't need to do the trailing arms because they are the same as the Cup Motorsport ones. Unless you want to go to GT3R spec it becomes a waste of time - you will not achieve any benefit.

Then, you need to change shocks. I recommend the kW Clubsport 3-way coilover. Its about $6K I think - very important to have the solid upper mounts option. I can give you settings for the kW that I reached after many, many attempts. The default setting is very soft IMO.

In the end, this is all worth less laptime than you think. Like, if you're thinking 3 seconds a lap you're already WAY overboard.

However, the car will steer extremely accurately and will hold an alignment (due to solid everything). It will also become more responsive to your inputs (both good and bad) at a stiffer setting. The new shocks and springs will also cope better with modern R-compound rubber, the Gen 1 shocks were designed for old N-spec MPSC, which are ****.

FYI, you're looking at about $10K all in (thats about what I paid including fitting aligning corner balancing and so on).

And no, its not worth it. You will still be nowhere near a 3.8RS, and still not close enough to a well driven 3.8, and certainly light years away from a 991.

However, you car will feel like a race car. You will also become a better driver - a stiff setup pretty much guarantees it if you are expecting to set any sort of laptimes. And if you jump into a 996 Cup for instance you will be slightly less shocked than the other guy who drives a stock gt3.


Ps* forget the sub-frame bushings. They are already aluminum.

Pps* you may want to think of engine mounts because now the engine/tranny will be the flexible part of the car.

 

I'm almost positive the GT based cars come with solid subframe bushings.

 

@bmardini
yeah... I was thinking more 0.3 seconds a lap...

thank you VERY much for your exhaustive answer, I wasn't aware gt3 has already got sub-frame aluminium bushings.

Your explication seems very accurate and logical, I know I will not be able to compete with 3.8 but I don't mind, I just want a bit more racetrack orientated car, but... what about daily driving ??..

How bad will it be ??... I know is very personal and subjective, but please try to give me an idea...

P.S. I have already got WEVO semi-solid engine mounts... what about a good semi-solid tranny ??... any suggestion ??...

 

Since you already have rear toe links, all your car needs now is adjustable sway bars. This will correct the dynamics of the car.

You could install monoball bushings and do engine mounts to "tighten" things up.

All the other stuff is for adjustability and tuning. Do you want that?

 

The daily driving has more to do with the shock settings and ride height.

I don't know about the tranny mounting, but I've heard good things about the WEVO. I'm thinking of going that way soon.

 

Solid tran's mount is a very good idea, makes a lot of difference to how the drive train feels and reacts and to how the clutch/throttle performs, way more than the solid engine mounts did.

Down side is 25% increase in engine noise but it sounds and feels how the car should be. Best mob by far.

I'm running RSS engine mounts and Torque solution's urethane transmission mount.

Thanks
Jay