ZL1-1LE & BC FORGED Wheels installed on Z28..is this too close?

[dlct3]

As the title states I'd like to know if anyone has tried ZL1-1LE Wheels on the Z28?

The front specs are identical, however the wheel manufactures are different so I don't know the barrel clearance, concave profile, etc. The rear sizing is different by 1/2" of wheel width and 15mm offset.
ZL1-1LE being 19x12 ET41mm vs Z28 19x11.5 ET26mm

*What type of clearance between the inner fender wheel liner and the back of the rim/tire be? It would appear with stock alignment I still have approx. 1/2" when I test fit these above.

[j o n]

This tool will help you better understand the difference in wheel/tire spec
https://www.rimsntires.com/specspro.jsp

Remember the the ZL1 1LE has 325's in the rear v the square 305 setup of the z/28

[dlct3]

Originally Posted by j o n

This tool will help you better understand the difference in wheel/tire spec
https://www.rimsntires.com/specspro.jsp

Remember the the ZL1 1LE has 325's in the rear v the square 305 setup of the z/28

Great Tool! Thanks.

I had test fit a set of BC Forged 1LE spec'd wheels and the gap between the inner fender liner and the actual tire (Michelin 4S 325/30-19) was around 17 mm closer which maybe left appox. 1/2" of clearance vs. the 1" it started with on my Z28 wheels (which are fitted with Bridgestone RE11's in 325/30-19) I just don't know what's too close for comfort as far as clearances go when the wheel/tire deflect under load, etc.

[aris]

Originally Posted by dlct3

As the title states I'd like to know if anyone has tried ZL1-1LE Wheels on the Z28?

The front specs are identical, however the wheel manufactures are different so I don't know the barrel clearance, concave profile, etc. The rear sizing is different by 1/2" of wheel width and 15mm offset.
ZL1-1LE being 19x12 ET41mm vs Z28 19x11.5 ET26mm

*What type of clearance between the inner fender wheel liner and the back of the rim/tire be? It would appear with stock alignment I still have approx. 1/2" when I test fit these above.

So I think the correct rear offset for the 19x11.5 Z28 wheel is actually 32.25mm

I had previously heard the 26mm spec, and was told it was stamped on the inside of the wheel. I checked the inside of my wheel and it's stamped with 32.25mm. I also tried to test fit some tires with a fitment tool using the 26mm spec and found that it wasnt the same as stock.

[dlct3]

Originally Posted by aris

So I think the correct rear offset for the 19x11.5 Z28 wheel is actually 32.25mm

I had previously heard the 26mm spec, and was told it was stamped on the inside of the wheel. I checked the inside of my wheel and it's stamped with 32.25mm. I also tried to test fit some tires with a fitment tool using the 26mm spec and found that it wasnt the same as stock.

But I read it online? ��

Actually, that would make more sense.. the set I tried were slightly wider (in the tire section width) and the amount of gap change inside next tot he inner fender didn’t equal up to the 17mm and extra tire width combined. I appreciate your help and I’ll test for an actual OEM ZL1 1LE wheel next week and post results.

[cdb95z28]

Originally Posted by aris

So I think the correct rear offset for the 19x11.5 Z28 wheel is actually 32.25mm

I had previously heard the 26mm spec, and was told it was stamped on the inside of the wheel. I checked the inside of my wheel and it's stamped with 32.25mm. I also tried to test fit some tires with a fitment tool using the 26mm spec and found that it wasnt the same as stock.

This. 32.25mm is correct

[pat_t]

Originally Posted by dlct3

... I just don't know what's too close for comfort as far as clearances go when the wheel/tire deflect under load, etc.

If it helps, I run my front 325/30/R19 Trofeo R's about 5mm from the strut, static at ride height. And that's ok for track - i.e they don't seem to touch even under high speed cornering load.

[MrRaZ28]

I run 325/30R19 Conti Extreme's all the way around and have had zero contact issues. I have not measured the clearance like Pat, but I've had them on/off the car enough to check to confirm.

[dlct3]

Finally got around to mounting a a set of ZL1-1LE OEM Wheels with GY 3R's along with a set of OEM ZL1 1LE specs BC Forged 2 piece Modular LE10's in ZL1-1LE oem spec'd 19x12-41mm & 19x11-11mm offsets fitted with Michelin P4S tires in 325/30 rears & 305/30 fronts.

The Front sets were no issues as they are identical fitment. Only difference was that the BC Forged wheels have a slightly smaller barrel and brake caliper clearance was reduced down to about 3mm. No issues with wheel weights, suspension, etc.

For the Rear I thought to be safe I'd buy a ZL1 Add-on's 3mm spacer for the rear. Both sets tested with 3mm SPACER installed.

After testing thread count on the lug nuts I discovered the 3mm took the full thread engagement from 9 down to 7 which from what I've read is still a safe # to operate with....any thoughts or opinions I'm open. The closest clearance would have been he BC forged set where the caliper is and it netted about 3.5mm at the closest point to hitting the inside of a spoke. You can see the tire sizes for reference and notice the M P4S is taller & wider than the tires on the factory Z28 wheel's which are Bridgestone Potenza R-11's in a square set up of 325/30-19. The GY 3R's are similar height to the M P4S, but a little wider than the M P4S and much wider than the B P RE-11's.

For clearance I think the only area I'm concerned about would be the rear inner wheel liner clearance which the best I can tell with the widest tire being the GY 3'R the gap has decreased from about 3/4" down to about maybe 1/2 and inch. With this current factory alignment does anyone seem to think they would rub under track use or hard cornering? I may never track the car, but curious.

[pat_t]

did you happen to do any weight comparisons between the sets?

[ronchev]

Originally Posted by pat_t

did you happen to do any weight comparisons between the sets?

This Im curious on too.... mosty with the OEM ZL1LE wheels

[SSEssence]

damn those BC forged wheels look amazing!!!

[MarineZLE]

Do you have daytime photos of ZLE wheels on Z28? Or rear end?

[dlct3]

Originally Posted by DualCool

Do you have daytime photos of ZLE wheels on Z28? Or rear end?

No sir I do not. Due to the back spacing differences they didn't stick out hardly anymore at all.