The new Greg Weld Wheels product is supposed to be available next month ... 15x7 fronts and 15x10 rears are gonna' save me 48 lbs of rotating mass for the wheels and I'm estimating appr. 12 lbs for the tires. With 60 lbs less rotating mass and the weight distribution improvement, can I expect my ET to improve by as much as .5-.6 ?

My car is a H/C car and is pretty strong ... should be easy 11.9's next time out to the track on Nittos. MT Street DR's will be going on the rears of the new wheels and MT street radials on the fronts.

No grinding on a 15" set of wheels ... hopefully, they won't cost as much as Bogart D10's.

 

You only have 11 less rwhp than me and you have 50 more rwtq than me you should be trapping higher than 115.What is your race weight?
When was the last time your tranny got looked over?

 

Why not run a narrower front rim like a 15x4?

 

I'm on stock WS6 '01-'02 17x9's on all 4 corners ... rears are Nittos and I'm new at drag racing at the track. That's why I posted this to see what you folks think what the difference would be with the 50 lbs less rotating mass by getting the drag wheels and MT Street DR's.

As for the tranny, it was refreshed by Chuck Johnson @ FLT back in March and should be fine. The car is pretty much stick weight minus the front sway car, jack, rear seats, etc.


... seriously thinking of doing just that. I guess if I'm gonna' go all-out and do the drag wheels, I should do the 15x4 skinnies up front.




I believe I can easily pick up a good 1/2 second and 5-6 mph with these drag wheels and MT's. What are your thoughts?

 

Drag wheels and tires = much less rotating mass. Less rotating mass = lower ETs! Depending on the combo (existing wheels), possibly as-much-as two tenths.

WD

 

When I've looked on Jegs and Summit, I don't see those new wheels listed with the correct backspacing for the rears + stock length rear end, ie. 15x10 @ 7.5 - 7.0 backspacing.

If you go full slick in back I think you'd drop an easy tenth or more from the wheel/tire swap, and a mph or two.

I went 11.6@116 h/c back in the day in the Formy @ stock weight + drag wheels + ac and some weight out.

camaro went 10.92@122 @ 3350 raceweight so figure 11.3@118 more at stock weight which is about right.

 

not to rain on your parade or anything but i picked up 1/10th and almost 2 mph switching from stockers to draglites. i think 5/10ths is setting yourself up for disappointment. just my opinion. good luck though

 

So, using the general consensus of dropping rotating mass is 1lb of rotating mass is equal to the equivalent of dropping 4-8 lbs of rotating mass ... if I'm dropping 50 lbs of rotating mass, which should equal the equivalent of roughly 300 lbs of dead weight ... most of which is from the front of the car, which should help with weight distribution. And going with MT DR's should give me about 2 tenths on my 60' time. Another general consensus is for every 100 lbs of dead weight removed, you should pick up about 1 tenth.

So, dropping the equivalent of 300 lbs dead weight + gaining 2 tenths on ET time + better weight distribution ... shouldn't that equal about a .5-.6 gain? I was reading some other folks posted .5 tenths and better gains just from tire and wheel swap. Of course, this is the Wild West of Forums where anything goes and much of what you read is fluff.

Thanks for weighing in guys ... anyone else?

 

I ran with Convo Pro's all the way around and ran 12.18 and then I ran with just the Convo's up front and Y2K C5 18's in the back and ran 12.26 and the 18's added 50#'s to the car.So there is not to much to gain...

 

You might pick up .1 - .15.

.5 - .6 is way too optimistic. Thats like dropping 500 lbs off your car.

 

.5-.6 I don't think so.

 

Agreed, MAYBE 2 tenths, I just bought some Bogarts & that is what I had in mind for the gain from the wheels.

 

I'd say .1-.15 drop for weight, and more if you are stepping up to a stickier tire.

 

So, on the brightest outlook of things, I guess with all condiered, I'm lucky to get .3 with a wheel/tire change ... skinnies up front and all. Kinda' disappointing ... guess I won't be spending a lot of money on weight reduction with wheels/tires. Maybe I should just have my FAST90 ported and get the car re-cammed ... should be good for 15-20 HP and for less money.

The new Greg Weld wheels sure are nice, though ... thought going from 17" stockers to 15" drag wheels, skinnies, tires would have gained me more than .1-1.5. Oh well, the addiction continues.

 

weight drop vs et dropped is proportional. losing 300# on a 4000# car is not a lot but it is on a 3000# car....thats why people have different results...

 

with 440 hp and only trapping 115 there is something serious mixed up on your setup...also that 1.70 60ft needs major improvement...i say at best .35 drop in ET with stickier tire and weight reduction...but 440 hp with a h/c car and only 115 i would be looking at that first...

 

I agree that doing a stock wheel and tire swap for lightweight wheels, skinnies and drag tires won't usually net more than a tenth or 2 depending on a lot of contributing factors. Keep in mind it's not just weight reduction but also contact patch and rolling resistance on the differences between fat front and rear tires vs. skinnies up front.

Also keep in mind that 60 foot times aren't going to be tied to your wheel choice but traction which has a better chance on a 15" wheel versus a 17" wheel due to the increased sidewall help.

Derek

 

chrs1313 the 440 RWHP is uncorrected and the car has a 12-bolt; level 5 tranny; 3.5 alum D/S BMR SFC's. Other than removing the usual stuff, i.e., spare tire, jack, rear seats, etc ... well, it's s pretty heavy car and I weighed 225 lbs on that run ... too much Holiday cheer/food.

I've lost 25 lbs and made a few other simple changes (for the top end) since then. So, I'll breaks 11's next time out (this week?) ... getting a couple of MT street DR's for the rears. That alone should allow easy 1.6x 60's .... hoping for 1.5x.

My 1.70 60 ft was on 315/35R/17 MT Street DR'S with 35mm front bar on and connected I have only launched as high as 1800 rpm because I kept breaking the tires loose. Come to find out when Mike Norris did my AR header last month, my Adj TA was set to zero and the LCA's were at the highest holes on the relo brackets.

Last time out, I was on 275/40R/Nitto's and pulled a 1.768 60' ... only launching at about 1600 .... afraid I'd spin ... got my best MPH and ET to date. And I could tell (with the new -1.5 pinion angle setting, lowest relo bracket hole setting for the LCA's, and front bar removal) the car was planting the tires solid ... FINALLY!!!

When I go back out this week, weather permitting, I'll get behind some big slick cars and launch at a higher rpm and then I should be getitng the car into 1.6's and 11's pretty easily.

Once I get the 275 MT Street DR's from JEG's, I should be achieving 1.5x's or better. A lot of that depends on practicing my launches since I'm new at drag racing. I don't think my MPH will improve much, though ... maybe 116-117 at most ... at least until more weight comes off the car.

As soon as I get the camera software I bought off Ebay, I'll post up some pics of the 'ram air' improvements I made this week to the car. I'm sure people who read this will think, 'yeah, another ram air preacher who should know ram air is worth nearly nothing'. But, I know ram air is not worth much and ONLY when the airbox is sealed well. However, I'll just say I wasn't afraid to use a dremmel tool on the front underside nose of the hood ... also stuck a Fast Toys JAAM plate and their 85mm airlid on my FAST90/Holley90/SLP85/setup. Without someone going FI, I don't think there's a car out there which will have a better air charge being forced into their intake. It should be good for something ... if not, well, I'll at least say I cut oue a few ounces of fiberglass form the nose and have eyeballs on the underside of the hood ...

 

What's your raceweight?

QA1 R drag shocks front and year, and skinnies up front would be what I would do next.

 

I don't see a 1/2 sec gain off wheels either. Also, I would go 15X4 not 15X7 up front.