tsy911

Hi all

I just picked up an '88 951 as my new track car. I am very new to Porsches and this is my first one (although I have been looking for some time) and I have a question of why the staggered setup on the 944?

I can understand running a staggered setup on a 911, but since the 944 is very well balanced I would think a square setup would handle better?

My car has 996 17" twist wheels right now, 7" up front and 9" in the rear. There seems to be a ton of space for bigger wheels and tires.

For now, I'm planning on running 225s up front and 255s in the rear which seems like a forgiving setup but I feel like it will understeer a lot?

Am I missing something about the P Cars that makes them different?

I'm looking into getting another set of wheels and am wondering about 17x9s in the front as well.

Once again, forgive my ignorance. I'm coming from a Miata and an RX-8 (prior track cars) so I have a bit of learning to do!

Thanks for any help given!

tom

racer

1) 996 wheels weren't standard

2) Staggered set up is because Porsche ran a staggered tire size to.. wait for it.. PROMOTE UNDERSTEER. With the 911/ 911Turbo out there killing everyone who lifted off the gas, they learned to engineer in an UNDERSTEER characteristic.

Yes, a "squared" set up can be quite fun on a 944. Of course, base wheel for an NA car is squared

Also, I've noticed that running a 225 and larger up front makes the car a bit less enjoyable on rutted/crowned roadways as those large treads follow the biggest tracks.

Base tires on an '88 951 were 205-55-16 front, 225-50-16 rear. Popular "upgrades" were 225-50-16 front and 245-45-16 rear.. but nowadays its not easy finding matched sizes in 16".

You really need 7.5 or 8" fronts.. then you can run a 225-245 without issue. Rears, 255-275, depending on offset, rideheight and any suspension changes.

9x17 up front? I imagine some shock tower clearance may come into being.. again... may depend on alignment, ride height etc.

V2Rocket

the understeer is terrible though...safe, yes, but annoying on twisty roads...im at the point of considering wider front tires to dial it out...kopkje9ogpkjso

thirdgenbird

i run a square setup on my 924s with no complaints.

tsy911

[QUOTE=racer;8643245]1) 996 wheels weren't standard

Yes, definitely optional!

2) Staggered set up is because Porsche ran a staggered tire size to.. wait for it.. PROMOTE UNDERSTEER. With the 911/ 911Turbo out there killing everyone who lifted off the gas, they learned to engineer in an UNDERSTEER characteristic.

Yes, never lift!!!! Unless you're good at driving backwards! Once again, I can understand Porsche not wanting to kill all their 911 customers with the staggered setup, but I don't see that it's a good idea on the 944.

Yes, a "squared" set up can be quite fun on a 944. Of course, base wheel for an NA car is squared

So does the 944 handle better than the 951? I've never driven the 'base' 944. Almost bought a 944 spec car instead of the 951 but never got to drive it.

Thanks for the replies guys!

tom

83 944

So for the track is having a wide square set up better or having a huge staggered set?

M758

For a 944 na the square set-up is the way to go. Better balance and you can rotate the tires for better wear. For a 951 the extra power can use a bigger rear tire. Which handles better? 944 is sweeter. However the 951 has more grip due to wider tires. On the end they both have the same basic chassis so will be about the same.

eric951turbo

good tire size thread for my archives...

thanks guys

M758

For a Turbo the answer is complicated. If you are at stockish power levels then 245 front and rear work pretty well. 255's front and rear can work well to. Fort up to about 300 hp you can alos run 275's front and rear, but you need to get custom wheels to get the perfect offset for 275's in front.

That is about as much tire as you can get on the front of a 944. However you can get more rear tire and at ever increasing hp levels you want all the rear tire you can get. 295, 305, 315. You can get alot for rear tire on a 944 body, but I do forget how big you can go under the stock fenders.

Anyway most NA cars 2.5L or even 3.0 968 cars work better on square since they just don't put more than low -mid 200's to rear wheels. So you drive these cars with alot of front tire to make them fast.

Turbo's can put ALOT of power in the rear tire and due to that you are always working on chassis set-up that gets that power to the ground.

When it comes to overall track balance smaller fronts will introduced some understeer, but if you are running really fat front tires and even wider rears you just try to adjust the chassis to compenstate for the generated understeer.

My 944 spec has only 132 whp so I am fine with 225's all around using 15x7 wheels. I could try to put on 245's (can't due to racine class rules) and the car might go a bit faster. It would have the same balance, but have to carry a heavier tire. Not a great idea with such low hp. It might be bit faster, but also more costly since 245's are more expensive tires than the 225 15" size I run now.

For 944 S2 or 944 Turbo at stockish power levels 245/45 R16 are great tires for 16x8 wheels. However for 17" wheels 255's may work too. Alot depends on the tire you run and what tires size options there are as you want to keep to a 24.9-25.2 inch overall diameter to keep the gearing good. You may find that the older Porsches tend to use a slight smaller overall tire diameter as compare to the new cars and that limits tire options slightly. I would not go with a larger diameter to get more width as what you gain from 10 mm of width you lose from the worse gearing on taller tire. I might even go as far as 275's on 200-300 hp 944, but only if I really needed the extra speed that comes with extra cost. 245 or 255 would work just fine.

YoungerThan944

The PO of my car stumbled upon an alternative setup - run a crappier set of tires on the rear

I wouldn't recommend this setup, and will be buying a full set of better tires when these wear out - but my car is very neutral at the limit.

User 52121

Try a different alignment?

I run 235's up front, 285's in the rear... and I have no issues with front grip. I usually place in the top-5 out of ~40+ cars in my region's autocross events (and I'm usually one of only 2 944's - everyone else is in 993s or Boxsters), and in DE events the car feels very balanced. I can alter the oversteer-understeer characteristics by tweaking my sway bars. In fact, the way my car sits now, it rotates TOO well - works good for AX, but on the track, trailbraking becomes a concern. I plan to dial some of that out before my next DE by stiffening the front bar a smidge.

V2Rocket

before the crash the tires were aligned straight...now that the car is coming back on the road, i may set it to a little toe-in

83 944

spencer why say toe in? i dont know what would be better toe in or out. but i did a few degrees out and the car handles awesome up front. i run 225/50/16 on my 951 fuchs all the way around. i have turbo front and rear sways and lowerd the front and rear of the car and couldnt be happier. well i could i just have to finish my turbo swap =P haha

doabarrelroll

This is a great thread. I didn't realize that the staggered setup was more ideal to promote understeer. Running the turbo s engine on my 15x7's is pretty oversteer happy already not to mention constantly spinning the rear wheels.

From what is being said, the more ideal setup might be 7.5 in front and 9 in the rear? We do have our engines in the "right" place but I would think that the additional rubber in the rear would be absolutely necessary is you have 250+hp.

Dawgz83948

Yup, I have traction issues with 275 rear rubber in 3rd. Next upgrade may be 295's.