JClaw

iTrader: (17)

Reason I'm posting this in the 1/4 mile forum is because this decision has everything to do with traction and little to do with handling. Whether I go with coilovers or Struts/Springs my car HAS to handle better than the Stock SE suspension it's sitting on (or I'm gonna go ).

Anywho, coilovers like the Cattman/Progress ones have the ability to adjust ride height between 1" and 3" lower than stock while Struts/Springs have a fixed ride height. Reason I'm concerned with this is that I want my rear end to be significantly HIGHER than the front. I want the rear high and the front dropped to the ground.

In addition to stiffening up the rear, doing this keeps the center of gravity that much closer to the front wheels and makes it that much harder for the front to lift under hard acceleration, thus improving traction. To do this I'm going to run my normal tires (215/60/15 or 25.1" tall) in the front and taller, 215/70/15 or 26.8" tall tires in the rear. This alone will jack up the rear 1" or so and fill the rear wheel wells nicely.

I would want to lower the rear very little, less than an inch or maybe even keep it pretty much at stock ride height and drop the front a good 1.5-2.0.

Reason I'm asking is that struts like AGX and Illuminas have the ability to adjust rebound/dampering so you can simply set it super stiff at the track. But coilovers like the progress ones only adjust ride height (even though they're pretty stiff in themselves.

So what's better for improving traction? Being able to adjust the ride height or stiffness? I am really convinced that jacking the rear/dropping the front DOES help significantly but I'm not sure it is more important than being able to adjust stiffness. Thoughts?

DandyMax

iTrader: (7)

Given that both are pretty stiff and likely decent at controlling body pitching I'd be tempted to go for coilovers just for reasons of weight. They are quite a bit lighter than struts/springs, especially on the front. I'm not sure that a height difference of 1 to 2" would really make that much of a difference... the center of gravity probably wouldn't change much in terms of forward/backward. Wouldn't the rear spring rate still be the main factor? I dunno my brain's mush right now...

JClaw

iTrader: (17)

I put rubber studs in the rear springs and zip ties on the front springs -- this lowered the front about half an inch and raise the rear about 1/2 to 3/4 of an inch. Just that made a significant improvement in traction, to the point where 2nd gear doesn't spin at all on the street and 1st gear doesn't spin at the track when launched off idle. All that despite a broken LSD, one wheel burnouts, regular all-season tires that retail for 50 bucks each and a car that's badly in need of an alignement.

Just that little difference in front/rear ride height give the car a raked look -- sort of like muscle cars in the late 60's if you want. It may not have moved the center of gravity much, but it takes a much greater effort from the car to raise the front, especially considering the driver sits just behind the drive wheels. That way, all the weight behind the front axle "pushes" down towards it. I wish I had a side profile picture of the car -- I'm sure you'd understand. It really doesn't take much.

I may even try putting a 30-40 lbs hunk of steel on the front radiator support. It would slow me down by about .05 but the increased traction might be worth it. I've seen guys with turbo civics do this.

BEJAY1

iTrader: (19)

You've got the right idea about the zip ties and studs/spring blockers. That helps prevent the car from lifting in front and squating in back under acceleration. It really has little to do with ride height, rake, or the center of gravity though. The same car could be slammed or lifted and as long as the susp doesn't give it'll be the same result. I would think in a FWD you'd want the exact opposite setup of a RWD 60's muscle car but I couldn't explain why.

Like this


Also, I'd think adding front weight to be self-defeating. Try removing the rear speakers, deck, toe hooks, metal seat back, and even trunklid first to accomplish the same. And on the front, pillowball mounts, traction bars, and alignment to help the launch.

JClaw

iTrader: (17)

Why would I want that? The center of gravity has shifted rearward in the pic you've shown above. This means there won't be as much of a transfer on the launch, but the only difference that makes is that there isn't as much weight pushing on the front wheels. I've asked around and all the FWD cars cutting really good 60 foots without weelie bars have jacked up the rear. There's an all motor CRX pulling 1.68-1.70 60 foots and low 12's at my track and he put taller tires in the rear, plus a big wheelgap.

http://www.honda-tech.com/zerothread?id=285747

"5) Weight transfer is a function of the height of the center of gravity, the track width or wheelbase, and the acceleration. Total weight transfer is reduced by lowering the center of gravity, widening the track, lengthening the wheelbase, or reducing the acceleration. We are not frequently interested in that last option."

I've also asked a guy that runs an 8-second FWD Charger and he said a vehicle loses more time raising the front than squating the rear under acceleration. He says he prefers to concentrate on preventing from end rise. Dropping the front to the ground with a jacked rear end certainly helps this.

grey99max

iTrader: (12)

JClaw, I have Tokico Illuminas lowering springs and struts on my '99. The springs dropped the car 1.7 inches in the front and 2 inches in the rear, leaving the rear about 1/2 inch lower than the front. Not ideal, but the adjustable struts let me set struts to 5 (max control) at the strip, which helped a lot on launches.

I followed your advice about rubber blocks in the rear springs, and set the rear back to stock height with four blocks on each side. Plus, the car rode much better on the street. Then, I mounted Dave B's old 15 inch DRs on the front, and it did look like the old muscle cars. The front was so low that I had to be careful staging - the brackets for your traction bars would sometimes trip the lights when staging! I'm still pulling 2.1s and 2.0s 60-ft launches, but I need more practice. I hope the new Edge torque converter will help on launches - I'll find out next season.

Because the 15" DRs spun so much, I also still use 255x50x16 BGF DRs, which are 26 inch tires, so next season I want to try the ratcheting cargo straps to pull the front end down on the bigger tires. The rear blocks are good - you can easily change the lift - the adjustable struts work very well, lowering springs get me closer to the ground, and the Jbars keep the DRs pointed straight ahead.

JClaw

iTrader: (17)

Ideally I would want aftermarket rear springs with stiff spring rates like yours, but at stock ride height, and front springs that lower like all aftermarket springs (1.5-2.0). Too bad they don't make any. Taller DR's are definately the way to go (235/60/15 BFG's would be nice, 26.1" tall instead of 23.9" like you have now).

When you pull 2.0's, do the tires spin? It may simply be that the auto has crappy gearing, not traction...

I want to pull consistant 1.90-1.95 60 foots on real street tires. I love street tires for one thing -- no rolling resistance. Unlike slicks or DR's they pull like a **** after you've launched. I did the test - had both my slicks and streets on the same wheels (sawbaldes) and there is no question that after the first 60', they pull harder MPH, 60' to 660', 60' to 1320', 330' to 660', you name it. All the more impressive considering I launch at 5000-6000 on slicks and 1500 on streets.

So if you have two identical cars, one with slicks and one with street tires, say the slicked car pulls a 1.80 60' (what I usually pulled), the street tire car will probably only need a 1.90 60' to keep up with it.

DandyMax

iTrader: (7)

But the question is, the traction you got, how much was really due to any height difference between rear and front and how much was from the fact that you basically had a super stiff suspension so no compression was taking place? ie-- just like not having springs at all, only a solid link.

I suspect it's the latter.... The weight of the car acts vertically downward. Any extra "push" onto the front is only the component of that force along the angle of inclination. With our fairly long wheelbase (as opposed to a small Civic hatch), I wonder how much that changes? You may be right, I don't know, I'd want to think about it more, and see what kind of rake angle you'd have.

With my Illuminas and Eibachs (set fully stiff) I don't feel like I'm getting any squat on takeoff... but I should have someone camera me so I can see for sure. I'd be more curious to see what would change if you swapped your current setup (stock suspension plus blocks, ties etc) for a set of coilovers or aftermarket springs & struts. That'd be a better comparison than stock versus blocked springs.

grey99max

iTrader: (12)

Interesting.... JClaw, so you feel that DRs or slicks have lots more rolling losses that street tires after launching? Those 225x50x15s were screaming through first and second in the last two track sessions I got in. I was going to switch back to the 255x50x16s, but broke my motor. Those DRs put 9.7 inches on the ground, but have the traction I think I need. Maybe I'm going at this backwards....

What size/brand of street tire would you pick to replace the larger DRs ?? I have 16x7.5 wheels on the car and the big DRs now.....

JClaw

iTrader: (17)

I know. That's the problem. I want to do it once and do it right.

The thing is that everyone and their grandmother has an aftermarket suspension except me, and they don't seem to be getting any better traction than me for it. Most people posting in this section seem to be getting 2.3 60 foots most of the time, even on aftermarket suspensions.

JClaw

iTrader: (17)

Definately. Here's an example, a few timeslips. Two runs on street tires (the second timeslip is very pale, but it says 13.68@104.5 with a 2.13 60'):



Now with slicks:



Rule of thumb is 0.1 off the 60 foot makes you 0.2 faster at the end of the track. So if I hypothetically pulled a 1.93 60' instead of a 2.13 on my 13.68 run, I would have been just as fast as this 13.32 run with slicks -- except with slicks I needed a healthy 1.76 60' to pull this (although, to be fair, I also pulled a 13.35 with a 1.84 60', but the same concept applies: slicks DO slow you down after the launch).

That is why street tire MPH is so high: It really pulls harder.

My tires put a ridiculously small 6.3" contact patch to the ground ( ) and they have almost no thread left. So nobody's going to accuse them of being the reason why this car hooks good off the line

Definately go with BFG 235/60/15. The fatter the sidewall, the better it hooks. That is why turbo civic guys go with 13-inch wheels = fat sidewall. The smallest wheel WE can fit is 15" so go with a 15-incher.

DandyMax

iTrader: (7)

But you know as well as I do that's not really a good comparison. There are so many other factors at play: weather, track prep, car weight, driver skill, more VQ35 TQ over the VQ30, tire pressures etc etc... My best 60' on DR's was 2.12 but that's only with less than a dozen runs of practice or so total and at the end of the season in cold weather on poorly prepped tracks. I'm sure I can do better than that come next year.

Maybe in your case it's simply that blocking the springs worked just as well as having an aftermarket suspension, and you have a well prepped track, lighter car with a VQ35, are a better driver etc.. who knows?

But just for fun I may get a chance later on to do a quick calc to get an idea how much that weight component would add with rake angle...

What did you say you wanted to do? Drop 1-2" in the front and keep the rear stock height?

Nealoc187

iTrader: (23)

Seems like a non question to me... coilovers are the only ones that allow you to adjust what you want to adjust. Shock stiffness doesn't have anything to do with weight transfer that is all spring action. Shock stiffness just controls the bouncing of the spring. It doesn't control the initial weight transfer.

I've got a feeling that the heigh difference is going to have very little to do with your 60' though, it's preventing the weight transfer that helps your 60'. I think the difference in height between the front and rear probably only adds a few pounds of weight to the front end cornerweights, whereas preventing the weight transfer keeps hundreds of pounds from leaving the front tires. You could always cornerweight your car to find out for sure though and avoid any guessing. But yeah, the issue of coilovers vs shocks and springs for your application is not even something worth questioning.

BTW I've found in all my passes that .1 off the 60' takes more like .13 to .15 off the 1/4 mile, I think that .2 rule is unrealistically optimistic. I don't know what your actual slips have showed you, but when I take .3 seconds off my 60' (which is exactly how much better my 60' was almost every time I used slicks), my quarter mile dropped by .4 seconds. That's a .1:.133 ratio.

JClaw

iTrader: (17)

Don't think so... rear still squats when you push it down with your arms. Spring rates are still the same.

Say, drop the front 2.0 less than stock and raise the rear 1.0 over stock. We would need our wheelbase to calculate, I guess.

EDIT: That is the only picture I have of the car right now. You don't see much but see how raked the car looks with JUST maybe 1/2" lower in front and 1/2-3/4" higher in the rear:

Nealoc187

iTrader: (23)

Also, I don't know how much this matters to you but are you planning on driving around with the rear jacked up and the front slammed every day? I've never been one to mod for aesthetics, but driving around with your car like that every day would look absolutely retarded imho. To me there's a differences between modding for performance and doing something that makes the car look completely stupid every day. With coilovers you can adjust the height at the track and then make it look normal again for driving around.

If you get ground controls you can get whatever spring rates you want for like $30. Get some crazy 1000# springs and your rear end won't be squatting at all without the need to block the rear of the car. Say 500lbs transfers from the front to rear on launch, with 1000lb rear springs (times two because there are two springs) your rear end would only squat 1/4".

JClaw

iTrader: (17)

If I remember well you said you hated the ride on your old GXE with ground controls? What's the difference between ground controls and Coilovers like D2, Cattman/Progress and whatnot.

But you were rolling on 17's, right? Does being on 15's with 60-70 profile tires improve ride comfort significantly compared to 17's with low profiles?

LOL, you got a point. But with taller tires that fill the wheel wells better it doesn't really look funny because the wheel gap ends up between similar front/rear so it's more even and fills the wheel wells nicely (25" front and 27" rear, basically). But yeah I guess the coilovers just got a big .

Even if I take the .15 rule, 2.137 - 1.761 = 0.376. 37.6 hundreds x 1.5 = 56.4 so 13.680 - .564 = 13.116, about 2 tenths faster than I was. Also the 13.3 run was in cooler, nicer weather than the 13.6.

DandyMax

iTrader: (7)

Ah ok I thought you'd pretty much got your springs "solid" (wasn't hard spacers I take it?)

Anyways, I can't say for sure but I tend to agree with Neil that weight transfer is likely much more the issue than front/back corner loading.


And Neil I know the stiffness setting is only the shocks but I still set mine stiff in the hopes that if there does happen to be any "bounce" in the springs that it'll subsequently be dampened out quickly. That was more a factor when I had wheel hop problems prior to getting motor mounts and JBars.

In retrospect I kinda wish I had coilovers but didn't have the budget for good ones 1.5 yrs ago when I got the Illuminas. But JClaw I'd get them if I were you. Oh and I think wheelbase is about 106 IIRC...

grey99max

iTrader: (12)

Thanks - I'm going to check into getting these tires and matching wheels for them. I use nothing but BFG TA/GForce tires and DRs, because of the great handling. Plus, people can't tell which tires I have mounted with a casual look at the car.

One side issue is that I use nitrous almost off the line, so good traction is important on the launch.

" When you pull 2.0's, do the tires spin? It may simply be that the auto has crappy gearing, not traction... "

Yes, they certainly spin - nitrous is either on or off, and I launch with a 50-shot, then go into another 75-shot after the shift. The auto is geared pretty good, and the new VLSD helps on launch.

Neal had a good point about the rake on the street, but I change tires for every session, so the 225x50x15 DRs are really short, which drops the front a bunch. Normal driving tires are the same front and rear - 225x50x16 - so the car sits level when driving to the grocery store. So, at least for me, that's not an issue.

Congrats on this thread - lots of good information so far.....

JClaw

iTrader: (17)

If you need track only tires why not jump to real slicks? A nice set of 26-inchers would get rid of any wheelspin and you probably wouldn't have to worry about snapping axles since you're auto. I have a love/hate relationship with slicks because I have a 5-speed but I've never heard of snapping an axle with an auto, launch is much smoother.

EDIT: Searched around a bit. Looks like I'm not the only thinking the front/rear height bias thing might work:

http://www.honda-tech.com/zerothread?id=1035587

11.5 at only 114 mph. 60 foot must've been REALLY good.

Nealoc187

iTrader: (23)

There's no question that having the front lower and the rear higher works to some extent... more weight on the front. That's physics. Most of the gain though will come from reducing weight transfer, moreso than the little bit of weight shifted to the front by jacking the rear of the car up. You could quantify all this by getting the car corner weighted before and after jacking up the rear. My point is that it looks retarded and I wouldn't install a setup that was like that all the time. If it were a trailer drawn race car I wouldn't give a crap but I refuse to have a car that looks like a giant clown shoe rolling down the road. It's not worth the extra millisecond gain to look like a retard imho. That leads us to coilovers.

As far as the guys getting 2.3 60' times, you know - at least you should know - that 60' times are 99% driver. Once the driver has reached his limit that's when suspension setup comes into play. You put a guy who can't launch the car in a car with a great suspension setup and the 60' times are still going to suck. So that comparison is totally useless imho. Most people just can't drive as well as you, so comparing your suspension to theirs is moot.

Coilovers - The ride on my coilovers was stiff and harsh. On rough roads I hated it. I don't know how roads are where you live but being as it's canada I assume they are pretty similar to my roads, potholes and patches every spring, etc. So a choice has to be made. Stiff suspension that is good at the track and sucks on rough roads, or soft cushy suspension which is good on rough roads but sucks at the track? Can't have it both ways. Real coilovers have the advantage of increased suspension travel so there's less chance of bottoming out the suspension than with GCs. I see no reason to go with GCs nowadays that you can get Teins or D2s or Ksports for about the same price as GCs and the shock of your choice.

To answer your question about 15s vs 17s - there is definately a difference with stiff suspension. My car was much more comfortable and bearable on rough roads with 15s on it. Even switching from a 45 to 40 series 17" is noticeable.

grey99max

iTrader: (12)

Actually, I've been thinking about that very thing, but finding wheels wide enough for real slicks is a problem.. I didn't find anything with a 10-inch or wider wheel that would mount on a Max, at least not where I was looking.

Anyone have an idea where to find wide 15-inch wheels? I know from this forum that some of the more radical Maxes roll on slicks, but no clues on wheels used.. Maybe I should post in the Classified Wheels-Tires forum??

I was going to switch to Raxles this winter anyway, so the car could handle slicks without breaking something if I do. (one less thing to fail) My current automatic is from a 37K-mile 99 Infiniti VLSD, with the Jimi DR mod, Mobil 1 oil and a 16K GVW front-mounted cooler. It works quite nicely under nitrous, and shifts hard on 1-2 and 2-3 - really bangs the gears. 3-4 shifts hard as well, and after the 1-2 shift, I'm pushing a 125-shot - at least. The new custom Edge converter w/3K stall should round out the automatic package with some lower ETs... It goes in next week, along with a 99 Infiniti motor for winter recreation.

Of course my ultimate dream is to switch to a VQ35 and see what I can do with it next year. But that's another story - question is, build it or buy it???

Nealoc187

iTrader: (23)

You aren't going to break an axle. There are quite a few auto maximas out there putting down more power and getting out of the hole harder, Jime, stevechicagoSC, ferhan, etc and they aren't breaking them.

Why are you talking about 10" wide wheels? You don't need a 10" wide wheel you can fit the 26x6" slick on a 5" wide wheel if you want... we that use slicks use normal wheels for them. Millenias, stock wheels, K1s, maybe some Welds.

JClaw

iTrader: (17)

So real coilovers it is then. At least I still have fat sidewalls. And it's gonna save a few pounds, too.

I wasn't trying to imply that most guys can't drive, just that most guys have aftermarket springs with a sagging rear and 200 lbs boom boxes. And I wasn't implying I had any skills at all. Been driving stick for a year, minus the winter.

Nealoc187

iTrader: (23)

Well you didn't imply it but I said it flat out. I'm not ashamed to say it. Some people are just good at certain things, and others are good at other things. You can drive well. Others can't drive so well. I know I can't paint a picture well, I can't write a song well, but I know I can drive well. I didn't really "learn" to drive well. My first ever 1/4 mile pass was a 2.20 60', in a frickin civic with 17" wheels and cheapo rubber band tires. Some people are good without any practice, some people start out not so good and can get good with practice.

My point was that comparing 60' times is for the most part a comparison of driver skill, to a lesser extent track prep, and hardly a comparison of suspension setup. It's not controlled enough to eliminate all those other factors such that you can say "this guy's suspension setup is better for drag racing that this other guy's setup."

grey99max

iTrader: (12)

My point was that I don't want to worry about breaking an axle - I figure the Raxles will take care of that. I've been eliminating the weak points as I learn.

Real slicks - humm. Hoosier 26x10x15 (10" on the ground) requires 9-10" width rim. Hoosier 26.1x9x15 (9" on the ground) requires 7-8" width rim. Mickey's ET 26.0x10x15 (9.6" on the ground) requires 10" width rim, all according to Jeg's.

When using my 26" 255x50x16 BGF DRs (9.7" on the ground), on launch I spin them through first and into 2nd. I figured that if I venture into using real slicks, I should start with 9-10" on the ground. A 6" slick seems too narrow to me.... ??? Yes, there's always somebody faster than me - and you - but they didn't begin that way. Two years ago I thought that a 16.2 ET was pretty good - now a 13.6 is just where this season ended.

Nealoc187

iTrader: (23)

No they don't, I'm looking at the manufacturer specs right now. The manufacturer spec for the hoosier 26x10x15 is 8" rim minimum to 10" maximum, you can even fit it on a smaller rim if you try. The MT ET Drag can be fit on an 8" rim without a problem, even a 7". The website states 10" wheel was the size that they measured it on... i.e. the measured sidewall width and such will vary depending on the wheel width that you install it on. Search the .org... I can think of 5 people off the top of my head that have 10.5" slicks mounted on 7" and 8" wheels, myself included. You can fit the widest slick you would ever dream of putting on a maxima on a 7" rim with a little effort, an 8" rim with ease.

The difference between a slick and a DR is dramatic. I can't spin a hot 8.5" slick, and I'm putting more than 400 to the ground. I wasn't suggesting you get 6" slicks I was making a point that you can fit slicks on skinnier wheels than you might think.

I wasn't suggesting that you not get new axles if it gives you peace of mind. Peace of mind is worth more than gold. I was just saying that I don't think it is something you have to worry about, to give you peace of mind.

grey99max

iTrader: (12)

OK - but my numbers were from Jeg's home pages on those tires..... So if I decided to go with the MT ET 26x10x15, do you think this tire has superior grip to the BFG 255x50x16 DR ?? And do you think they would mount on Kosei 15x7" wheels? (These were the widest 15" alloy wheels I could find quickly...)

EDIT - I just saw your edit of preceding post:
"The difference between a slick and a DR is dramatic. I can't spin a hot 8.5" slick, and I'm putting more than 400 to the ground. I wasn't suggesting you get 6" slicks I was making a point that you can fit slicks on skinnier wheels than you might think."

Guess you had just answered my main question - thanks... This thread has been an education in traction for me!!!

I believe that a tight suspension, with the tail raised on rubber blocks, and short DRs on the front, and adjustable Illuminas set to maximum dampening, and JBars, has helped me drop my ET this year. Any time spent moving the car up or down has got to slow you down on launch. You can put your street tires back on afterwards.

Nealoc187

iTrader: (23)

Looking at the specs for the same sized tire on the Hoosier and M&H Racemaster sites, I do believe you could PROBABLY squeeze that tire on a 15x7" wheel with effort. I've seen a 26x10.5 slick on a 7" wheel. It takes effort on the part of the installer, lots of lube, and alot of air pressure to get it to seat, but I think it could be done. If you're getting a set of drag wheels consider getting some 15x8" Welds, they are a little more expensive ($150 a piece) than the K1 but also lighter and wider, for increased performance and easier installation.

Personally I'm a fan of M&H racemaster. I ordered from them directly and the guy I spoke to on the phone at M&H was very helpful and nice and they've earned my repeat business. I've used MT as well and had no complaints, but I really liked my M&Hs and they (like any slick probably) lasted forever. I made probably 100 passes on them and you couldn't even tell they'd been used. They had an easy 300 passes left on them. I did significant burnouts each run. Their website is www.intercotire.com if you want to check them out.

JClaw

iTrader: (17)

I put around 120 runs on my 23X8.5 M&H and the passenger side slick looks pretty good (probably another 120 left) while the driver side was burned to pulp before it blew off the sawblade with 9 psi in it on a hard launch (6550 straight dump with the 6 puck), taking out 1st gear along with it and damaging my differencial and axle when I was dumb enough to roll a significant distance back to the pits on it.

Damn one wheel 2nd gear burnouts.

If anyone wants a lone mounted slick, I got one.

Nealoc187

iTrader: (23)

Is 9psi a typical pressure for you to run? You really need screws if you are going to run that low pressure in slicks I'd say.

I usually ended up at about 11.5-12psi in my slicks. I usually started out around 13-14psi and dropped it in .5psi increments until it started to slow me down through the traps, then I raised it back up another half psi. Both of my slicks looked identical when I sold them.

JClaw

iTrader: (17)

No but 23-inchers have NO sidewall, so I had to make that compromise.

This was a learning experience for me. Made many, many errors this year. Had to. Won't do 'em again.

My next slicks will be 24.5X8.5 mounted on the widest wheel I can find (7.5 or 8.0) with tubes and rim screws, and I won't be satisfied until I get a 1.6 out of them with the new Final Drive. Meantime I'll be using the Yokos with granny idle launches.

EDIT: I think I'm going to go with the K-sports.



They had a group deal at 740$ shipped a while ago.

grey99max

iTrader: (12)

I took a look at the Intercotire web site - quite an inventory there. Thanks. I would prefer a wider wheel anyway, so I'll chase the Weld wheels down next. I can't believe I would need a 10" slick, but the shorter/narrower M&Hs look much better. - like JClaw was using. If they're good enough for him.....

With the M&H/Weld combo for the strip, I could save the look-like-stock DRs for freakin' out the street kiddies on the weekends!

JClaw

iTrader: (17)

Hell you might want to go with the same as me (24.5X8.5 w/tubes and rim screws).

I didn't remember how long the auto gearing really was compared to 5-speed...

The first column is the automatic with the 24.5's and the second is what my 5-speed gearing will be next year with 4.4:1 FD:
http://fatboyraceworks.com/gears/ind...raph&Compare=1

grey99max

iTrader: (12)

Wow - great interactive graph program - I don't know auto gear ratios and final drive off the top of my head, but something seems wrong with the Auto numbers you plugged in to make the graph. ??

When I used the 225/50/15 BFG DRs, I would come out of third and into fourth gear well before the finish line. That's a trap speed of about 102MPH. Wheel diameter is 23.9".

When using the 255/50/16s, then I was still in third at the end. Still around 101-102MPH. That tire has a 26.1" diameter.

EDIT: I found the automatic gear numbers in a couple of places - they match what you entered - the listed final-drive ratio was shown as 3.619. When I run the graph program, the 23.9" DR numbers don't match what I experienced - but the 26.1" DR numbers are approximately what I remember. ?? My tranny is a RE4F04V, if that matters - I couldn't find numbers for that tranny. Now I'm confused - oh well..... /EDIT

Both tires gave similar results for ET and MPH for a given setup - but the shorter tires spun a LOT - usually screamed through first and well into second gear. (with working VLSD). Now if I used a real slick of the same diameter but with much more traction, maybe I could cut ETs a bit. That's my goal for tires. Your 24.5X8.5 slicks are really close to the 23.9" BFGs. Maybe even shorter would be better ?? If there are any ....

The new Edge torque converter stalls at 3K RPM. Internals are supposed to hook up much better, as well. I'll launch at 3K, go into a 50-shot immediately, and if the short slicks can hang on and not spin so much, things will be good.