I'm sure that this has been asked before but I'm not having luck with the search. Is anyone running 7.5 inch wide 17" rims on the front of their 88's? If so what offset? From the wheel offset diagrams floating around it looks like it might be a tight fit. Your thoughts are appreciated.
Nolan
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07:23 PM
PFF
System Bot
TopNotch Member
Posts: 3537 From: Lawrenceville, GA USA Registered: Feb 2009
I have 17x7 rims on my 88, 38 offset all around. The front wheels seem to stick out a bit, because as you know, 88's are wider in front. But it rides just fine with them.
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07:49 PM
Boostdreamer Member
Posts: 7175 From: Kingsport, Tennessee USA Registered: Jun 2007
I have 17x7 rims on my 88, 38 offset all around. The front wheels seem to stick out a bit, because as you know, 88's are wider in front. But it rides just fine with them.
Is it the '88 front that is wider than the '84-'87 front or the rear that is narrower than the previous years?
------------------ Jonathan 1987 SE wrecked parts car 1985 SE parts car 23K miles
I did some calulations a few years back regarding the offsets, but I cannot find them at the moment. That said, the offset is directly related to the wheel width. With a 7.5 inch wheel width, I think you will need a rather high offset (over 50mm) to get the outer rim edge to line up with the fender edge at the same place as stock. Whether that would give you enough clearance on the inside when turning the wheel at full lock is another question. You could cheat the outside out a little, to gain some room inside.
Lemme look through my stuff, see if I can find the info...
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09:16 PM
Fformula88 Member
Posts: 7891 From: Buffalo, NY Registered: Mar 2000
Just to clarify, the offset is the distance from the wheel center line to the wheel hub (where it attaches to the axle hub).
The 88 Fiero has a 15x6 inch wheel, with a 37mm offset. Basically what that means is that the distance from the wheel centerline to the hub is 1.45669 inches, making the distance from the wheel hub to the outer edge where the fender is will be 1.543 inches.
If you want to keep the outer edge at that distance and prevent the wheel from sticking outside the fender, you need a 7.5 inch wheel with an offset that leaves 1.543 inches from the hub attachment to the outer rim.
The half point would be 3.75 inches, so the offset would have to be 2.207 inches (or 56mm).
The downside is that this means that there must be enough room for 5.957 inches of wheel from the hub point inward, to clear the A-arms. Stock leaves just 4.45669 inches inside the hub. So you need an additional 1.5 inches of room inside the fender for a 7.5 inch wide wheel with a 56mm offset.
Now you can trade some outer edge room for inside room. The difference is the wheel will stick out some.
I went with 17x7 rims, with a 45mm offset on the front. This made the outer edge stick 0.184 inches beyond the stock rims outside the sender, and left 0.396 deeper in the fender. I had no issues, and it looked ok and not like it was sticking way outside the rim.
In your situation, I am sure you can get a 7.5 inch rim to fit in general. The question is what will the offset be, and how much will stick beyond the rim. If it has a really high offset to minimize the amount outside the fender, inside clearance may or may not be an issue. With 2 inches more diameter, you do buy yourself more room too (as the rim will fit deeper over the a-arms with the larger diameter).
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09:28 PM
zigaroo Member
Posts: 361 From: Frederica, Delaware Registered: Aug 2009
I've been staring at this this afternoon myself and am finally making sense of it, hopefully. I'd still need someone to tell me if what I were purchasing were good or not, though...
You don't want to go past or be ontop of the red line on the left or you may have clearance issues... The single blue line is where the 88 front stock tire would be... The double blue lines is 88 rear stock tire would be (and other years, just read the yellow rectangles ontop)... The double red indicate the fender location...
Remember, this is the wheel itself, and not the tire. I keep having to tell myself that my wheels aren't sticking out beyond the fender, it's the tire doing it.
[This message has been edited by zigaroo (edited 09-12-2009).]
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09:29 PM
Fformula88 Member
Posts: 7891 From: Buffalo, NY Registered: Mar 2000
I thought I would add a couple pics to illustrate how the rims I chose worked (I have since gone back to new, stock rims to get the factory look. Why is a long story). Rear rims where 17X7, 35mm, which is stock width and offset.
Current look:
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09:32 PM
Fformula88 Member
Posts: 7891 From: Buffalo, NY Registered: Mar 2000
I've been staring at this this afternoon myself and am finally making sense of it, hopefully. I'd still need someone to tell me if what I were purchasing were good or not, though...
You don't want to go past or be ontop of the red line on the left or you may have clearance issues... The single blue line is where the 88 front stock tire would be... The double blue lines is 88 rear stock tire would be (and other years, just read the yellow rectangles ontop)... The double red indicate the fender location...
Remember, this is the wheel itself, and not the tire. I keep having to tell myself that my wheels aren't sticking out beyond the fender, it's the tire doing it.
That's a good diagram and illustrates how the offset affects the distances very well! The OP may also find this helpful, an online offset calculator... http://www.1010tires.com/WheelOffsetCalculator.asp
[This message has been edited by Fformula88 (edited 09-12-2009).]
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09:36 PM
zigaroo Member
Posts: 361 From: Frederica, Delaware Registered: Aug 2009
Tires on the stock rims are stock size, 205/60 front, 215/60 back, and they are Fuszion HRi's (secondary brand made by Bridgestone)
I am not 100% happy with them. They are supposedly a max performance all season tire. However, I think they give up fairly quickly in aggressive turns. I have had the car on the track at Watkins Glen, and in the turns the biggest limiting factor was certainly the tires and not the chassis. They were fairly progressive however.
I chose them for price. They were the cheapest option I can find, and I tend to run thru rear tires every 15K miles (30K on fronts) so I usually go with cheaper choices. For the price I cannot really complain, but I bet a set of Bridgestone Potenza RE960AS Pole Position's would be a heck of a lot better. (I am going to try those when this set is finished.
[This message has been edited by Fformula88 (edited 09-12-2009).]
Excellent information! Thanks for taking the time to respond.
I'm not sure what offsets are available in the rims that I looked at so I will investigate however, I suspect that the 7.5 is going to be a bit much to handle.
Pluses all around! Nolan
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10:28 PM
Nilknarf Member
Posts: 289 From: Bristol, IL, USA Registered: Jan 2008
What was the aftermarket rim size and offset on the fronts?
Are you asking about mine? They were 17x7's, 45mm offset front. They looked pretty good, although they did stick out a little more than stock.
BTW, I loved the handling and steering response with the low profile tires. However, I went back to stock when I badly dented one of the fronts on a pothole.
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10:44 PM
Fformula88 Member
Posts: 7891 From: Buffalo, NY Registered: Mar 2000
Excellent information! Thanks for taking the time to respond.
I'm not sure what offsets are available in the rims that I looked at so I will investigate however, I suspect that the 7.5 is going to be a bit much to handle.
