951 86 Vs 87
#16
Instructor
early offset has more wheel options. period.
It's true what Lart says, that most wheels THAT FIT late offset will fit without spacers, while on early offset, most wheels will require spacers.
However EVERY wheel that fits late offset will fit early offset as well, in most cases with correct spacers. On the other hand some wheels that fit early offset will never fit late offset without cutting the body.
It's true what Lart says, that most wheels THAT FIT late offset will fit without spacers, while on early offset, most wheels will require spacers.
However EVERY wheel that fits late offset will fit early offset as well, in most cases with correct spacers. On the other hand some wheels that fit early offset will never fit late offset without cutting the body.
#17
Racer
Thread Starter
Hi Christoph,
Thanks for clarifying, but now my next question is: will one inch spacer affect drivability??
I am asking as i have D90 wheels that i like but since they are late offset i will need my understanding about 1 inch spacer to make them fit..
Thanks for clarifying, but now my next question is: will one inch spacer affect drivability??
I am asking as i have D90 wheels that i like but since they are late offset i will need my understanding about 1 inch spacer to make them fit..
#18
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They required spacers and studs or spacer like the H&R with studs, both which will add $$$ to the equation, for that fact any Porsche wheel 5x130 will fit but without proper offset they will look like these
#19
Instructor
I was using big spacers on the rear. With such big spacers you would need what lart mentioned - either longer studs, or studded spacer (the one that has it's own studs, where you bolt the spacer to hub studs, and then you bolt the wheel to spacer's studs. ..as opposed to a bolt-through where you only put the spacer on hub's studs, and then bolt the wheel to the same studs).
I never used such a big spacer up front.
As for driveability, there's no change, because the rubber stays where it's supposed to be. You only compensate different wheelcenter shape. Actually you can improve drivability by using the thickest spacer that fits without scratching the fenders, increasing axle width but the difference would be negligible - you will not feel any effect.
Some say spacers increase stress on suspension, but i'd say it's a bull%$ myth.. It's as stressing as mounting a low ET wheel. actually mounting a heavy wheel would be far worse than lightweight rim with a spacer. In my opinion it all comes down to calculating the exact thickness you need, getting the lightest possible spacers not to increase unsprung weight (OEM spacers are nice - rigid yet of very light alloy), mounting the wheels you wanted, and adjusting geometry.
The only way you can go wrong with spacers is if the rubber will rub either the fenders or the inside of the wheelwell. Bear in mind the alignment changes with suspension travel, so the angles are different when compressed than on "idle".
The most popular mod to the body is rolling the rear fender lip - the one that is on the INSIDE at the edge of rear fender - google it. It's easy as pie, and it makes a difference if you want your wheels to be nice fitted with the body. Late model cars had that modification done by factory, early offset cars had an ugly 1cm lip that rubs tyres if mounted to much to the outside.
One more thing - For spacers you really want them to have a centering ring unless they are slim ones like 3-8mm..
I never used such a big spacer up front.
As for driveability, there's no change, because the rubber stays where it's supposed to be. You only compensate different wheelcenter shape. Actually you can improve drivability by using the thickest spacer that fits without scratching the fenders, increasing axle width but the difference would be negligible - you will not feel any effect.
Some say spacers increase stress on suspension, but i'd say it's a bull%$ myth.. It's as stressing as mounting a low ET wheel. actually mounting a heavy wheel would be far worse than lightweight rim with a spacer. In my opinion it all comes down to calculating the exact thickness you need, getting the lightest possible spacers not to increase unsprung weight (OEM spacers are nice - rigid yet of very light alloy), mounting the wheels you wanted, and adjusting geometry.
The only way you can go wrong with spacers is if the rubber will rub either the fenders or the inside of the wheelwell. Bear in mind the alignment changes with suspension travel, so the angles are different when compressed than on "idle".
The most popular mod to the body is rolling the rear fender lip - the one that is on the INSIDE at the edge of rear fender - google it. It's easy as pie, and it makes a difference if you want your wheels to be nice fitted with the body. Late model cars had that modification done by factory, early offset cars had an ugly 1cm lip that rubs tyres if mounted to much to the outside.
One more thing - For spacers you really want them to have a centering ring unless they are slim ones like 3-8mm..
#21
Drifting
The brake calipers have a bigger piston in the 87 and later then the 86 calipers. So don't miss match or you will have brake proportioning problems. And the brake proportioning valve is different. 87 deleted the oil cooler on the tranaxle also. The difference on the rear suspension is an updated control arm, hub, disc, and the pistons in the caliper. The front suspention changes were the lower control arms, spindles, hubs, discs, caliper(with bigger pistons). The 87 and later engines have a low oil level sending unit bolted on the oil pan the is not found on the 86 with an upgraded oil pan and pickup tube and engine wire harness with the oil level wire. The 87 engine block differs in the ballance shaft bearing size and is drilled in the front to accept the timing belt auto tensioner. The inner tie rods are longer for the offset wheels difference. The computer is updated for the oil level unit as well as the wires under the dash and the instrument cluster. The instument cluster in the 87 has abs, airbag, and oil level added to it. The oil level unit utilizes the explanation mark as the idiot light as well as the e brake and no oil pressure. The 87 and later exhaust manifold from 1-4 header is updated with an expansion joint to aid from cracking unlike the 86 models. The 87 and later crossover is updated to a two piece to help aid in removing the wastegate and was updated again in 88 turboS models with a 1 piece collector at the headers and a reversed wastegate pipe tie in to help air flow. If the car is a non ABS car, it cannot be converted to an ABS easily because we're the ABS pump sits inside the rear front passenger wheel well there is a recess in the body panel and a mount added for the ABS pump as well as the brake line holes being a different in size in front of the battery for three brake lines to pass thru as well as the other brake line holes in the front of the chassis. The wastegate mount is different on the 87 and later as well as the wastegate itself having a smaller body due to smaller cooling fins. The steering wheel has an airbag as does the passanger dash unlike the 86 as stated, and has an updated spring hub behind the steering wheel for the airbag. The 87 is an updated car from the 86 model. I have had both year models. However everything from a 87 non ABS car can be bolted to an 86 chassis. But an 86 is still a great car!
#24
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When I bought my 86 Turbo; the previous owner had a nice set of 17" Fikse wheels with late offset mounted with ~25mm spacers mounted. Having also driven an 88S; the steering felt slightly different, but was acceptable during the test drive before I bought it. After I got it home and did some hard mountain driving; it became noticeable that the front end did not feel planted like an 88S. Did some research and talked to some suspension engineers and they said the spacers affected the scrub radius. The offset and scrub radius were changed to allow for steering control with ABS brakes; a similar move in 911's steering geometry change when the 964's were introduced. Since I planned on overhauling the suspension; the cost of the correct offset Fikse wheels (could not find a used set of Fikse's, as early offset 17" wheels are scarce and would have to buy new) was more than updating to the later suspension. So I updated the suspension from a wrecked 88S. I came across this article on Rennlist regarding scrub radius (see article by Bill Verburg) https://rennlist.com/forums/racing-a...-handling.html . Also Tarret Engineering (http://www.tarett.com/items/944-prod...sba-detail.htm) has a warning on their website regarding the strength of early offset control arms when mounting stiffer swaybars. It all boils down to whether you can tolerate the difference in steering feel and handling with spacers and what you plan to do with your car.
#25
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When I bought my 86 Turbo; the previous owner had a nice set of 17" Fikse wheels with late offset mounted with ~25mm spacers mounted. Having also driven an 88S; the steering felt slightly different, but was acceptable during the test drive before I bought it. After I got it home and did some hard mountain driving; it became noticeable that the front end did not feel planted like an 88S. Did some research and talked to some suspension engineers and they said the spacers affected the scrub radius. The offset and scrub radius were changed to allow for steering control with ABS brakes; a similar move in 911's steering geometry change when the 964's were introduced. Since I planned on overhauling the suspension; the cost of the correct offset Fikse wheels (could not find a used set of Fikse's, as early offset 17" wheels are scarce and would have to buy new) was more than updating to the later suspension. So I updated the suspension from a wrecked 88S. I came across this article on Rennlist regarding scrub radius (see article by Bill Verburg) https://rennlist.com/forums/racing-a...-handling.html . Also Tarret Engineering has a warning on their website regarding the strength of early offset control arms when mounting stiffer swaybars. It all boils down to whether you can tolerate the difference in steering feel and handling with spacers and what you plan to do with your car.
#26
Rennlist Member
The comment on the 1986 exhaust is only half true, as many 1986 model cars have the bellows and the two piece crossover. Mine has both as well as most of the other 1986 models that I have seen.
As for spacers, I would agree they do change the steering feel. I have two sets of wheels for my car. I have early phone dials and the car drives incredibly well with them. I also have a set of late offset cup 1 wheels and the car tram lines and squirms a lot with them, however they look so much better in my opinion. Recently I have been running the phone dials exclusively as the car is so much nicer to drive and I finally finished polishing them and they now look decent.
As for spacers, I would agree they do change the steering feel. I have two sets of wheels for my car. I have early phone dials and the car drives incredibly well with them. I also have a set of late offset cup 1 wheels and the car tram lines and squirms a lot with them, however they look so much better in my opinion. Recently I have been running the phone dials exclusively as the car is so much nicer to drive and I finally finished polishing them and they now look decent.
#27
Drifting
The major correction was the front control arm being longer for the scrub radius. In a sense Porsche just installed an offset hub in the rear which doesn't change the suspention travel like the front. Basically they just added the offset of a spacer to the rear hub. Tire design has a lot to do with how the car tracks strait. If you have the same tires on the two different rims, one using spacers and the other not, and the car tracks different on both sets then I would be stuck scratching my head. But more people have different tires on there spare set and the car will handle different due to the tires design. Add some spacers on an 86 in the front and it may feel even worse. But if your car is aligned properly and it has tracking issues its most likely the tire design not the spacers creating the problem.
#28
I would take a 1987. 1987 was a year when factory made a lot of enhancements to these cars. 1987 have possibilty to install several options which came to 1988 cars. For example 10-speaker system wiring is there readily available even tough that option came to 1988. Also possibility to use bigger rear speakers. 1987 models have also attachment points for divided rear seat. 1986 model might be lighter, but if you would like to install options afterwards, 1987 is your choice.
#29
Racer
Thread Starter
Thank you guys, for all your comments and info, I am still looking for the correct car, I am discussing with one person let's see if the sale go through
Keep sending me your recommandations
Keep sending me your recommandations
#30
Drifting
You can add all the options but ABS easily. The chassis is modified with a mount and dished panel to hold the ABS pump behind the passanger front tire in the fender.