Current configuration of my narrow body 964 works very well indeed at 335bhp. It's fast, nimble and fun to drive.

Development will continue and I'm wrestling with converting it into a wide body. We know that getting to around 375 bhp (or more, given budget) will be easy, but...

...when do we make the decision to go wide and accommodate wider rubber? Currently running 250/650R18f and 265/645R18r in Hoosier R80s and am pleased with the results.

Any equations involving KE will be immediately discounted.

 

As soon as you stop drifting it through #9......

 

Kai, look on the 964 forum for Geoffrey Ring...Mobil 1 tribute livery avatar(can't rememeber his rennlist name) ...You have similar mods...I believe his is a wide body conversion.

 

Yep! Know his car well.

My question actually revolves around when does it become necessary, rather than how to do it.

IF it happens, then the only questions revolve around displacement and weight (i.e. GT4 or GT3)...or money, to be more precise.

 

Found him-Geoffrey is his rennlist name.

 

Couple of factors which I'm sure you've already considered.....

Flares and wider tires equate to more drag. On the shorter, twisty tracks that's less impactive than on a high speed banked track.

Increasing your WHP may be easy to achieve but it's definitely more wear & tear on the motor and drivetrain.

If you're running NASA's GTS series tire width has no impact. If you run in the ST series any tire over a 265 series adds +.3 to the calculation. BTW, are you planning on running the Nationals at Road Atlanta at eh end of August? If so you should consider running both GTS3 and ST3. You could win 2 classes and seriously kick ***....

 

We make a great wide body kit in CF

 

Do you need speed or grip?

If it's speed -- leave it narrow.

m

 

That's the question, is it not?

At what point in engine development does one need more rubber - as this would be the only reason to go wide.

 

I've run with ST (as GTSU due to lack of current dyno) and done well, but those Vettes are obnoxiously loud (kidding) and hard to get around. Have to add a bit of weight to get to GTS4, so no way to GTS3.

 

While not a 964 my observations should hold valid to a certain extent.

What I have found is that I have lost top end speed, however it more than makes up for it on the tracks I run with cornering ability, as you can brake later into and take the corners a little quicker, and get on the power a tad earlier coming out.

So it is more about your driving style than HP. Do you like going faster in the straights or the twistie bits.

 

Kai,

Road Atlanta! NASA Nationals!

I hear it calling.....

 

Currently the only we can keep up is by pedaling like crazy through the twisties.

If one thinks about it, at least in the PCA, ALL of the monster GT3 and GT4 cars are widebodies. My little car works very well and I honestly believe I'm driving well enough again, but wonder how much more HP the car can handle in its current configuration.

At the moment, there is no way in hell I can keep up with the likes of Polk, Forsythe (Glen's old car), Yonker's old car or a couple others. The rest we can beat, as well as a few of the 6Cups.

 

But I get so Skeered....

 

The Vettes aren't nearly as loud as the Mazda RX7's I've raced with in ST2 for years. Fortunately they've all gone to ST3 since the rule change starting in 2013. They're unbearable just sitting next to one on grid....

You need to dyno your car on a Dynojet to accurately make your weight/whp calculations.....