Bigger wheels
#1
Bigger wheels
Good morning everyone,
Please excuse my lack of knowledge - I tried to figure out the offset info
I was wondering if anyone would be kind enough to tell me if the following tire/wheels would fit my 1987 944 turbo without any rubbing on the fenders or lowered suspension(not more than 1 inch):
Offset: Front ET45 Rear ET54
Wheel Size: 18x8.5 Front and 18x10 Rear
Front tires are 235/40/18. Rear tires are 255/35/18
Thank You very much
K
Please excuse my lack of knowledge - I tried to figure out the offset info
I was wondering if anyone would be kind enough to tell me if the following tire/wheels would fit my 1987 944 turbo without any rubbing on the fenders or lowered suspension(not more than 1 inch):
Offset: Front ET45 Rear ET54
Wheel Size: 18x8.5 Front and 18x10 Rear
Front tires are 235/40/18. Rear tires are 255/35/18
Thank You very much
K
#4
I couldn't find the whole TSB in a quick search but I know it's been posted in the past so it must be out there somewhere. The jist of it is that Porsche's position on oversized wheels and tire's is that a 944 with 17" wheels needs upgraded caster blocks and adjusters and different wheel alignment specs than a car with 15" or 16" wheels. Porsche also stated that 18" wheels are taboo as the upgrades required to make this safe do not exist.
I found a part of it;
There's a lot more to the TSB than this, but it's all I could find in a quick search. Formerly, I'd been able to find the whole thing by searching for '18" wheel TSB,' but the current search software will not accept a 2 digit number.
I found a part of it;
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.
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.
Last edited by Dave; 03-17-2004 at 01:17 PM.
#5
You may need a 1/4" to 1/2" spacer on the front.Roll all the inner fender lips and you shoud be ok. Upgrade to the 968 caster blocks. You can get them from www.paragon-products.com for around $62.00 each.
#6
FYI.
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
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
#7
i have 18x9 front and back with 225 fronts and 265 in rear. I did have to use a spacer though but it has been fine. check out pictures at my website or send me a pm if you have some quesitons. ALso i was thinking of putting 235 up front i was going to try them maybe this week.
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#8
Originally posted by daniel951
i have 18x9 front and back with 225 fronts and 265 in rear. I did have to use a spacer though but it has been fine. check out pictures at my website or send me a pm if you have some quesitons. ALso i was thinking of putting 235 up front i was going to try them maybe this week.
i have 18x9 front and back with 225 fronts and 265 in rear. I did have to use a spacer though but it has been fine. check out pictures at my website or send me a pm if you have some quesitons. ALso i was thinking of putting 235 up front i was going to try them maybe this week.
#9
re;wheels
Thanks Guys,
I was always a bit wary of 18 inch wheels anyways.
I think I will just save more $$$ and get some Kinesis ones or wiat till someone wants to sell his used ones ;-)
I guess they are expensive for a reason
K
I was always a bit wary of 18 inch wheels anyways.
I think I will just save more $$$ and get some Kinesis ones or wiat till someone wants to sell his used ones ;-)
I guess they are expensive for a reason
K
#10
i haven't upgraded to the caster blocks or anything because i saw no need to. Right now the only reason i put spacers on because my offset was a little different compared to my 87 NA. on my 87 na i didn't need spacers but on my 86 951 i needed them for the front because it was hitting the spring. I haven't had any problems driving on them a 1 and 4months
#13
Originally posted by daniel951
i haven't upgraded to the caster blocks or anything because i saw no need to. Right now the only reason i put spacers on because my offset was a little different compared to my 87 NA. on my 87 na i didn't need spacers but on my 86 951 i needed them for the front because it was hitting the spring. I haven't had any problems driving on them a 1 and 4months
i haven't upgraded to the caster blocks or anything because i saw no need to. Right now the only reason i put spacers on because my offset was a little different compared to my 87 NA. on my 87 na i didn't need spacers but on my 86 951 i needed them for the front because it was hitting the spring. I haven't had any problems driving on them a 1 and 4months
Cheers
Jeremy
#15
I don't think control arm failure is necessarily the issue with 18" wheels (unless the car is lowered quite a bit, where the arm is less than parallel to the ground). It is the caster blocks that is at issue.