CA944

Well, a few months ago, I decided to swap my BBS Rims and tires from my 84 944 to my 87. Needless to say, I ended up wasting a brand-new set of performance tires in the rear. Turns out the depth of the rotors in the rear are different on those tow years. After a little research, I realized that they changed in 1987. My luck.

It is now time for new tires (& wheels maybe ) for the 944. What is the widest set I can fit without damage and does anyone have any pics???

Thanks in advance,

Sergei

Danno

Ah, you've found the dreaded pre-'87 vs. '87+ offset issue (23.3mm vs. 52.3mm). Well, it's not just the rotors that are different, but the entire suspension arm, hubs and spindles.

For big wide rims, you can easily go to 9/10" front/rear combo if you increase the offset to 65mm front/rear. This places roughly 0.5" more on the outside and 1.5" inches on the inside compared to stock.

Personally, I like a 10.5/11.5" front/rear combination so I can fit fat racing rubber on them. You'll need a 2.5" coil-over kit in front to clear the struts. Also you'll need to roll the fenders front/rear and strap the parking-brake cable tightly to the rear spring-plate.

Check out this guy that has a 335/35-18" rear tire. Must have a wide-body fender kit:

http://pages.prodigy.net/pjbloom1/_i...m1/index2.html

rfuerst

I have 17 inch 993 cup wheels on my 1987-944S,they are 7 inch up front and 9 inch in the rear,both are 52mm offset and have 225/45 front and 255/40 in the rear.They look great and no rubbing anywhere,plus the wheels are light.

Alan C.

My car has 10 and 12 x 17 with 275 and 315 tires. However, it is a widebody conversion. http://albums.photopoint.com/j/Album...519&a=13680091
You might want to get in touch with the people at Forgeline http://www.forgeline.com
Steve Schardt has done just about every combination on 944's
Alan

racewheel

have done numerous 18x10 and 10.5 combos for the car, priced about 1800 for the set. www.ccwheel.com

Dave in Chicago

I thought I'd heard of a Porsche tech bulletin regarding revised alignment for '87+ 944's with 17" wheels. Was it just a dream or is there some adjustment required?

rangelica

FYI, Here is the Porsche Tech Service Bulletin on 18 inch wheels.
Rick
'86 951

18-INCH WHEEL INSTALLATION NOT APPROVED
Article Text
1987 Porsche 944
Tuesday, August28, 2001 11:31AM

ARTICLE BEGINNING

TECHNICAL SERVICE BULLETIN

INSTALLATION OF 18" WHEELS NOT APPROVED

Model All Porsche Models
Group 4
Bulletin No. 9305
Date April 15, 1993

Concern:

Retrofitting 18" wheels on Porsche vehicles which do not have 18" wheels as original equipment is NOT ALLOWED.

General Information:

Endurance tests have shown that equipping certain Porsche vehicles with 18" wheels in an application not already approved by Porsche Cars, N.A. may result in loosened bolts and /or threaded connections on the front wheel carriers. This, in turn, may cause fractures in these components. Fractures may also occur in the front strut mounts and in the body in the area of the rear suspension as a result of the installation of 18" wheels not already approved for installation for this specific application.
Such damage can occur without warning and the vehicle may become very hard to control/steer as a result of the improper installation.
Porsche dealer personnel coming in contact with a vehicle that has been retrofitted with 18" wheels in an application not approved by Porsche, should inform the owner of the potential for damage to their vehicle and loss of steering control. Porsche Cars, N.A. should also be notified of any vehicles retrofitted with 18" wheels.

END OF ARTICLE

rangelica

Also,

Here is the Porsche Tech bulletin for adding 17" wheels.


Rick

'86 951
APPROVED WHEELS & TIRES: NEW SPECIFICATIONS
Article Text

ARTICLE BEGINNING

TECHNICAL SERVICE BULLETIN

17 INCH APPROVED WHEELS & TIRES

Model(s): 1987-On Porsche 944 (with M30 option) 1987-On Porsche 944S (with M30 option) 1987-On Porsche 944 T (with M30 option) 1988 Porsche 944 Turbo S
1989 Porsche 944 Turbo
1989-On Porsche 944 S2
Group: 4
Bulletin No.: 9303
Date: September 28, 1993

SERVICE INFORMATION

Concern

Installing 17" Porsche wheels on vehicles previously equipped with 16" wheels.

SERVICE PROCEDURE

Installation Information
1. Front and rear fender well lips must be reworked and/or checked for adequate tire clearance. See Fig. 1.

2. Suspension travel must also be checked. Parts such as brake lines, hoses and brackets must have adequate clearance.

3. New caster eccentrics, rear mounts and nuts must be installed in the front control arms. This change is necessary due to a change in caster specification on vehicles equipped with Porsche 17" wheels. The specification for vehicles equipped with 17" wheels is 3'-15'-45. See Fig. 2.



4. Vehicles must have a rear stabilizer bar.

5. When adjusting vehicles to new caster specification, all alignment values should be checked at that time.

6. When summer tires are used on vehicles with 17" Porsche wheels, snow chains cannot be used. If winter tires are used, only snow chains with Porsche Part Number 911 361 924 00 may be used.

7. Tire pressures for front and rear 17" Porsche wheels is to be set at 2.5 bar (36 PSI) at approximately 20'C (68'F).

8. When using this rim and tire combination, a 17mm spacer plate must be installed on the rear wheel hub. The customer must be informed that if the emergency wheel is needed, the spacer must be removed.

9. Not for Cabriolet vehicles.

APPROVED WHEEL & TIRE TABLE

Tire size Rim size Offset Position Note

225/45 ZR 17 7,t Jxl7 AH 65mm Front Summer tires
255/40 ZR 17 9 Jxl7 AH 55mm Rear (See installation
information
A through G.)

225/45 ZR 17 8 Jxl7 AH 52mm Front Summer tires
255/40 ZR 17 94.@ JX17 AH 68nm Rear (See installation
information
A through I.)

205/50 R 17 7;-i Jxl7 AH 65mm Front Winter tires
225/45 R 17 8 Jxl7 AH 52mm Rear (See installation
information A through G.)

NOTE: When using this rim and tire combination, a 17mm spacer plate must be installed on the rear wheel hub. The customer must be informed that if the emergency wheel is needed, the spacer must be removed.


PARTS INFORMATION TABLE

Description Part Number Quantity

Spacer Ring 951 331 611 02 2
Wheel Bolt 904 341 671 00 10

Wheel Nut 999 1 82 003 36 10
APPROVED WHEEL PART NUMBER TABLE
Size Offset Part Number

7;-i Jxl7 AH 65mm 96536212405
8 Jxl7 AH 52mm 96536212601
9 Jxl7 AH 55mm 96536212800
91.@ Jxl7 AH 68mm 96536212805


APPROVED TIRES AND SIZES (SUMMER VERSIONS) TABLE

Size Makes

225/45 ZR 17 Front Bridgestone Expedia S-01 Nl
255/40 ZR 17 Rear Continental Sport Contact CZ 91 NO
Pirelli P700-Z NO
Yokohama A 008P NO
Michelin MXX 3 NO or MXX NO Pilot SX


APPROVED TIRES AND SIZES (WINTER VERSIONS) TABLE

Size Makes

205/50 R 17 89 H M&S Front Bridgestone WT05
225/45 R 17 90 H M&S Rear Continental TS 750
Pirelli winter 210 Performance


SUSPENSION PART NUMBER TABLE


Suspension Parts

1. Rear Mount


Part Number Quantity Required
951 341 023 00 2 each


2. Eccentric 951 341 431 02 2 each
3. Nut (torque to 100 Nm) 900 910 115 02 4 each


END OF ARTICLE

Dave in Chicago

Rick - you are the man!

CA944

Yea Rick, somewhat demented but still the man

So now I have another question. Based on the above listed info, should I not be running 17" rims on my N/A 944? Personally, if they bolt up and don't rub, I can't see any reason why I shouldn't, regardless of what the Porsche Teck Bulletin has to say Am I being obtuse or do you all agree with me?

Whatever.....anyone have a pic of a 944 with 996 Take-off's ??

CA944

BTW, What is the M-30 option?

Danno

Ok, here's an update. Got two 275/40-17 tires in and mounted them on one front and one rear rim. Tire weighs 26.5lbs, so combined weight comes out to 43.5/44.5lbs F/R. They're so freaking huge, it almost looks silly:




As for clearance issues, front fits just fine. I'm going to have to fully roll the fenders instead of two 6" sections at 10/2 o'clock. Also the inside of the tire rubs upon the square metal tab that supports the brake-line. I already cut off a 1/4" corner of that tab to mount my 245/45-16 tires, so there's nothing else I could cut off. If there was a way to limit the steering, I'd like to reduce the steering stop a little. Also at the very front, the tire rubs on the fender liner. None of these clearance issues would post a problem at the track since they only occur at extreme steering angles like in parallel parking or U-turns.

On the rear, no problem with the clearances. Again, I will have to roll the entire top of the fender down to the front. Earlier, I had to strap the parking-brake cable to the spring-plate since it was rubbing on the rim. That clearance has now been taken down to 0.25". Under full compression, I would guess that the tire would actually rub on the inner wall of the fender about 6" ahead of the upper shock-mount bolt. So looks like a 275mm rear tire is the maximum that'll fit. There's actually room for a 295/35-17 tire if anyone makes such a size. And why not I wonder?

In summary, here are the final specs on my '86 951 set-up:

• FRONT: 17x10.5" (35mm offset/7" backspacing/11.25" overall-width), 255/40-17 tire
• REAR: 17x11.5" (25mm offset/7" backspacing/12.25" overall-width), 275/40-17 tire

So to conclude, the LARGEST tire you can fit in the back of a 944, is a 275/40-17. A 295/35-17 actually has the correct diamter of 25" and would also fit if you can find such a creature. And NO, a 315mm tire will not fit without a widebody kit, in which case a 335mm would also fit.

deni durrell

Sergei:
you've got tons of porsche resources in marin!! i am amazed everytime i pass through about how many porsche shops are there. must be that sears point is so close. anyhow i recommend "conversion techiques" for more info and stuff. they're in oakland.. @ 510.639.0911 .. . .

...still left wondering who was driving that black 951 with red calipers, tinted black windows, and BIG fm10s in Larkspur/Corte Madera - Damn, that was bad-***!

Kierf - ¿§?

I've thought about a wider fender for my 951 down the road. I saw GT Racing's website and see they offer a carbon fiber wide body front and rear. Has anyone used this? How well does it fit?

Steve Lavigne

Wow! Thanks for the info. One of these days I am going to have to follow in your footsteps with that setup. Did the tire shop have any problems mounting the 275's on the 11.5" wheel? The last time I have seen a sidewall at that angle was probably on my shifter kart, and it uses bias ply tires. I'm guessing that you are going to have some major transitional response with those wide wheels and relatively narrow tires. Be careful the first few laps.

On another note, I imagine that if you were to disassemble the steering rack and put some JB weld in the gears on the shaft on either end that you could limit steering movement. You'd of course want to make sure that the extra material didn't protrude into the bore of the rack housing.

'86 951
-Steve