weight savings of 18x9 with 305 MT ET Street R - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

2MCHPWR · 03-21-2017, 10:55 AM

I'm getting for my first outing with the Zl1 at a drag strip on april 7 so I ordered some MT ET Street R's 305/45/18. These seem to be best for a manual transmission (more shock than an auto).

I recently sold a 4th gen Fbody but still had some 18x9 TSW wheels 5x4.75 bolt pattern, 50mm offset. I sold the tires off of them, and my stock goodyears and used that money to buy the MT's (about $630 shipped for the pair).

Don't plan on using sensors; I know there will be DIC display errors but I will only put these on at the track and run with all nannies turned off.

The stock wheel and tire combo (rears, BFG g-force, almost brand new) weighed 69.5 lbs on my digi bathroom scale. The 18x9 TSW Interlagos wheels with MT ET Street R's weigh 52.5 lbs. 17 lbs per wheel weight savings in rotational mass is gonna be huge. I bet it will even show more HP on a dyno.

Since I still had an unused pair of TSW's, and just to shave off some more weight, I am also mounting up some used goodyear RSA 245-55-18 for the fronts but I don't have them yet but will update the thread with the weight savings they provide over the front stock wheel/tire combo. Bought them used for $70 (build dates very late 2015 and early 1026). I'm gonna guess that i'll see a 20 lbs diff at the minimum.

The rears are a little close to the inner wheel well (1/2 inch clearance at least) so I might use a 5mm spacer. I'll put some white-out there and see if they touch when I test drive on the street.

The stock lugs didn't didn't fit in the TSW; they are too fat. The 4th gen lugs are a different thread (m12x1.5). Went to autozone and got mcGuard lugs which fit but didn't leave enough room for a socket to fit so I hit amazon for some "tuner" style lug nuts in stock thread (14mmx 1.5).

Will post up completed project pics in a few days when the lug nuts arrive

Viczl1 · 03-21-2017, 02:06 PM

Great job Scott!!

2MCHPWR · 03-26-2017, 02:29 PM

this is what it''ll take to make the front wheels from my 98 firebird work.
1.25 inch spacer and a 5mm spacer on top of that.
Tuner lug nuts (from amazaon) 14mmx1.5 on the big spacer. Stock 4th gen m12x1.5 lugs on top of the 2nd skinny spacer.
Overall they stick out the same as the stock wheels 285's on 10 inch (these "skinnies" are 245 on 9 inch wide wheels).
not ideal but good enough for straight line duty

My cheapo Drag setup. Saves 28 lbs off the front, and 34 off the rear using 18x9 wheels (50mm) all around. I had the wheels leftover from my 4th gen ws6.
245 fronts goodyear GSA's bought used.
305 /45/18 rear MT ET Street R's - bought new.

03-21-2017, 10:55 AM	#1
2MCHPWR Drives: 2009 z06 Join Date: Jul 2014 Location: NY Posts: 136	weight savings of 18x9 with 305 MT ET Street R I'm getting for my first outing with the Zl1 at a drag strip on april 7 so I ordered some MT ET Street R's 305/45/18. These seem to be best for a manual transmission (more shock than an auto). I recently sold a 4th gen Fbody but still had some 18x9 TSW wheels 5x4.75 bolt pattern, 50mm offset. I sold the tires off of them, and my stock goodyears and used that money to buy the MT's (about $630 shipped for the pair). Don't plan on using sensors; I know there will be DIC display errors but I will only put these on at the track and run with all nannies turned off. The stock wheel and tire combo (rears, BFG g-force, almost brand new) weighed 69.5 lbs on my digi bathroom scale. The 18x9 TSW Interlagos wheels with MT ET Street R's weigh 52.5 lbs. 17 lbs per wheel weight savings in rotational mass is gonna be huge. I bet it will even show more HP on a dyno. Since I still had an unused pair of TSW's, and just to shave off some more weight, I am also mounting up some used goodyear RSA 245-55-18 for the fronts but I don't have them yet but will update the thread with the weight savings they provide over the front stock wheel/tire combo. Bought them used for $70 (build dates very late 2015 and early 1026). I'm gonna guess that i'll see a 20 lbs diff at the minimum. The rears are a little close to the inner wheel well (1/2 inch clearance at least) so I might use a 5mm spacer. I'll put some white-out there and see if they touch when I test drive on the street. The stock lugs didn't didn't fit in the TSW; they are too fat. The 4th gen lugs are a different thread (m12x1.5). Went to autozone and got mcGuard lugs which fit but didn't leave enough room for a socket to fit so I hit amazon for some "tuner" style lug nuts in stock thread (14mmx 1.5). Will post up completed project pics in a few days when the lug nuts arrive Attached Images

03-21-2017, 02:06 PM	#2
Viczl1 Drives: 2019 ZL1 Join Date: Dec 2016 Location: New York Posts: 162	Great job Scott!! __________________ 2013 Inferno Orange A6, bone stock

03-26-2017, 02:29 PM	#3
2MCHPWR Drives: 2009 z06 Join Date: Jul 2014 Location: NY Posts: 136	this is what it''ll take to make the front wheels from my 98 firebird work. 1.25 inch spacer and a 5mm spacer on top of that. Tuner lug nuts (from amazaon) 14mmx1.5 on the big spacer. Stock 4th gen m12x1.5 lugs on top of the 2nd skinny spacer. Overall they stick out the same as the stock wheels 285's on 10 inch (these "skinnies" are 245 on 9 inch wide wheels). not ideal but good enough for straight line duty My cheapo Drag setup. Saves 28 lbs off the front, and 34 off the rear using 18x9 wheels (50mm) all around. I had the wheels leftover from my 4th gen ws6. 245 fronts goodyear GSA's bought used. 305 /45/18 rear MT ET Street R's - bought new. Attached Images