My friend is buildin a '68 Chevelle drag car. He has to build a tranny, finnish the head work, cage it and other hosts of 'to-do' things on the list. Hes also talking about back-halfing the car with a Chris Alston rearend for tubs so he can run the wide ones. Heres the reason for this post and my question. How much does running a wider tire with tubs significantly make your car faster or quicker? I understand theres more tire foot print on the ground, so the tires would have more bite at launch, but if the car was hooked up and traction was the same at launch on either tire, then what does it matter for the rest of the 1/4 mile? he has 10" slicks on it now and can lift the front on launch, so it hooks up good. My opinion was wait on the back half till this next winter, the drag season just started, get your other things finished instaed and start racing. He thinks he'll jump up like 2 seconds faster with wide slicks. Does anyone here know of a person that use to run the original rearend and wheelwell space with slicks and then went to tubs with a wider slick, same motor, and improved their times? Id appreicate any input as well as maybe some genral explanations on why some people tub and some people swear by the skinner 10" slicks. thanks!
well, humm, good question, ill have to find out. is one obviously better than the other for drags? i dont know too much about drag tires and what is better to run.
if he does plan on changing the tires, depending on the size of the new tire, he might want to put new gears in the rear end. i have seen a car with huge meats and inproper gear ratio run on the drag strip. bogs the hell out of the engine. just my thought diego
If he can hook up that good with the 10" slicks, why would he wanna tub it?? If he put a 4 link setup in it, that would help, but bigger tires are just gonna slow it down, more rotating mass, and probably more rollout too. What makes this guy think he's gonna go faster? Besides there are guys running EXTREMELY fast on 10.5 inch tires, just look at the (gosh) 5.0 Mustang guys (sorry, did I swear?) My suggestion would be to save the cash on the backhalf, and all the shit you need for that and spend it somewhere else. Besides, tubs are outta style, I think. Just my opinion.
absolutely you will gain more ET with a back half set up.tubbing will increse traction by alot more than you think..
If he can lift the front at launch, He is getting excellent transfer.He dosen't need wider tires. Think about this, try and drag a 10" slick standing sgt.up under water. Now do the same thing to a 24" wide tire. You will see that the wind resistance on the wide tire takes more H.P. than the 10" slick. This only works if he's hooking up like he should.If he is adding a bunch more power then he might need a wider slick. Most of the wide street tires don't have the compound or side wall to hook up very well. If they do, they are not much of a good street tire.At least thats what I've always been told.--TV
he has the 4 link and racing shocks and stuff in the back right now with a 12 bolt. Thats my opinion too, just finish the tranny and motor work and race the season, save some cash and have fun! Theres a reason why slingshots and diggers and all the dragsters run the wide meats. you never see them run 10". Maybe it handles better at high speeds, kinda like a dually handles better when towing something, they can keep it straight without fighting the wheel much.(?) but i dont understand how it can impove your times.
hey alright, nice pic, ill definatly show him that. what kinda motor and drivetrain were you running in it?
I never liked the look of tubbed cars. I can appreciate the work and time spent..but. With the technology out there now in suspensions, tires, general chassis design, i don't see a need for having huge rear meats. Unless however, the car in question has HP and Torque numbers that exceed the realization of running on a 10" slick. I can't remember the guy's name, but a number of years ago when the '10 wide' racing deal started ( couldn't run anything wider than a 10" slick) this guy had a killer black '65 chevy Impala. Not tubbed, running i believe it was high 8's. I wouldn't tub anything..but thats only my worthless oppinion.
Slicks grow and crown at speed, reducing the footprint. That's why you don't do burnouts at high rpm. You'll get more traction with wider slicks as you go down the track. Backhalfing includes 4-link or ladder bars to increase traction also, and adjustments to reduce wheelies. Wheelies are fun to watch, but take away from ET. Backhalfing should make the car quicker. Without knowing all of the particulars of the car it's hard to say if it's worth the expense. But expecting 2 seconds improvement from wider slicks is very optimistic unless he's getting a lot of tirespin on launch. Didn't see your other post that he already has 4-link before I posted this. Doesn't sound like he needs it with what he already has. Maybe he's planning ahead? Hope this helps.. Mutt
Unless you're Warren Johnson, tubbing a car is mainly for looks. Look at all the 5.0 Mustang boys going Crazy Fast on nine and ten inch wide tires! Proper chassis set-up and design is more important than how much rubber ya got on the ground any day of the week! Also, some of your tire requirements will depend on your engine. A torquet 500+ cube mountain motor may well need the additional rubber, but a 9000rpm small block won't. As always, it's the TOTAL VEHICLE COMBINATION that matters most. That said, I actually plan to tub my 49 down the road and run the giant baloneys under the back with the nose in the weeds. In my case, it's strictly for looks. By that stage, the car will be running either a warmed over big block or a 348-409 if I can locate one...it won't NEED that much tire, I just want it! (I'm going for a Fat Jack style...low, mean, slammed and tubbed...stock hood, rollcage, etc...but that's down the road a ways.) Most of the Pro Street guys ran the big tires for cosmetic reasons. I like the look myself, so why not incorporate it into my final design? Sounds like your buddy's car is dialed in already...I wouldn't wanna mess with it!
I agree with FatHack...from what I've seen...there are plently of guys running 10's, 9's or even 8's on 10 inch tires. It's a matter of asthetics at that point....
I knew a guy that traded out tire/gear combinations in his Vega wagen till he got good and consecutive times, (high 11's) with a 350/350 ,and Monza rear end set up. But then like an idiot (Bigger is better) was his thinking and he dropped a 396/400 set up in it. Second pass on this combination, and the car was cocked in the air permenently. He failed to add frame strengtheners to the car. That was the end of that lil' Vega.
ive worked on a few tubed cars,even the ones that are set up right dont drive that great,besides wouldnt it be fun to outrun the guys that spent all that cash tubing his car with one that looks stock!
basically heres the set up. he likes to keep some things secret just like many serious motor builders, but the main set up is: 1972 4 bolt main 400, stroked 400, steel 350 crank (377in) 6" H-beam connecting rods .30 over keith black domed pistons dart 2 sportsman heads, 64 cc angle plugs, specially ported 215 cc intake runners 15+.1 compression 750 cfm carb (upgrading to a 1050 cfm dominator carb soon, with other upgrades) victor jr intake 300+/500+ duration, solid lifter isky cam 1.7 rollers w/ stud girtles hedmann headers tricked out HEI MSD 6AL ign. latterbars, 4 link, koni 3 way adjust shocks, moroso trick coil springs MT 10.5 slicks 12 bolt 4:11 posi TH350 8" 4200 stall converter specailly mixed race fuel with that combo and factory wieght of only 29,000 (looks alot heavier) gutted and lightened, its a scooter! he said hes planning on tubbing it cause later down the road he wants to try out a blown big block, but for the mean time wants to get the full potential out of the small block. Thanks for any input on the specs of the car vs needing tubs
Okay, I think some of the opinions here are valid, but, First we need to know what this guy plans on doing with the car. Is it a street car he is going to take to the drag races once in a while? Or is it a dedicated drag car? If it is a dedicated drag car, is he going to be running in a "super class" or will he be running in pro or super pro? Will he be just running it heads up on street legal "grudge match" nights at the strip? I ask because, as any E.T. racer knows only one thing is more important than reaction time...and thats consistantcy. Your buddy may well have good enough traction to pull the front wheels up now on the launch, but how good are his 60 foot times? Are the 60 foot times consistant to within a couple of thousands of a second on every run? With a set of wide meats he may be able to increase his launch rpm and the result would be quicker E.T.s. The wider meats would more than likely improve his consistancy a great deal. If you go to an NHRA track running super street (10.90 dial in super class) almost every car will be tubbed, even though with a 10.90 e.t. they really don't need wide meats to run that number, because the racers know they need the consistancy of not pushing the limits of a tires traction ability. So, tubbing his car may do wonders for improving his success at winning drag races, especially if he is E.T. racing. - Duane
I agree. If the car hooks well consistently with the 10" tire, there is no reason at all to tub it. If it does not hook CONSISTENTLY, tubbing it should help. My car is tubbed. I set it up to take a 16" wide tire (Only as a last resort!!!), but the tires I run are 30x13.5 MT ET Streets (11.5" tread) on a 10" rim. That setup would probably fit on a stock chevelle, but not even close on a 62 chevy II! The widest tires that would've fit in the stock wheel wells would be about 8" wide MAX (about 6.5" tread), and about 26" tall, which would not work at all with the amount of power I planned on making. I considered moving the springs inboard, and minitubbing it, but then I would have to build a new rear subframe, modify or lose the stock gas tank, and modify or lose the stock back seat. I knew the stock rearend wouldn't hold up, so it had to have a 9". Well if I was gonna go through all of that time and trouble, I'd might as well go all out and tub it, so I did. I think it looks pretty damn tough too!!! (it doesn't look like a cheezed out pro streeter to me, but I might be a little biased!!!)
A few questions..... How is the track surface where he usually races? Does he have alot of money to buy new 10" tires all the time. MOST of the sucessful small tired cars only run their tires for a few runs and then install new ones. where fatter tires will hook WAY better, and last a lot longer since they hook so well and will still hook good when a small tire wont because its used up...... its mostly about money...... All those wheelie popping stock eliminator cars are always running "new tires" and usually they run on national event tracks. I love small tired cars, and I especially love the BFG radial tired cars, (running low 8s on radials) But only on well prepared tracks..... there is lots more to it like converters, progressive nitrous controllers etc..... but if he wants to bracket race or run at "regular" tracks he should maybe tub the car.... the car will loose maybe a hundreth with the bigger tires, but, they will last way longer.... and I myself, wouldn't use that alston stuff either...... LUKESTER (former 10 1/2" tire racer).......
Snake9t9 hit the nail on the head... it's about consistency and upgrading to a mo' powerful motor at some point in time... but he ain't gonna shave no two seconds off his ET... the faster you go, the more you have to do to shave a tenth... I.E. if you have a 14 second car and you take a shit before you run... you can shave anywhere from a tenth to a half second off your ET (because of the weight, for one) But try that with a 10 second car and you won't tell a bit of difference... ok, bad analogy! Anyway, if he's in the tens now... he ain't gonna run 8's or 9's by back halving the car... I did a rear "Back Half" suspension on a car and it took two tenths off the E.T. It went from 10.80 to 10.67 (almost two tenths) But the owner of the car can now put it in the 9's if he wants to. Bottom line, he's stupid to tear into it now... tell him to wait until racin' season is over. Here's the car I back halved (and built). It used to have radiused rear fender wells and a bunch of other hokey 70's drag car crap on it...
[ QUOTE ] I went 10.0's at 150 in this. Street tires, no tubs. [/ QUOTE ] Damn that is a sweet car Rocket 88!! Love the steel wheels and sleeper attitude... you would have done well down here street racing in the 90's! Looks like you had the same size tire we have on the BFD ... M/T 29 x 10.50W They hook most of the time... but then again, we have a solid mounted rear end. Best 60ft 1.415 sec. Best 330ft 4.151 Best 1/8th mile 6.587 at 102mph Best 1/4 mile ET 10.508 Best mph 124.66 I know, it falls flat after the 1/8th mile... but the new motor is going to fix all that. Sam.
Pretty close Sam. The Chevelle should went went quicker given the mile per hour. But once you clicked it into hi gear and hit the other nitrous button she'd start black tracking and her ass would squirm around. Kind of exciting when you're going a buck forty or so! The best part of that car, bench seat with a column shift! I'd love to drive an open car one day. It would be cool to feel the wind blasting at you!
[ QUOTE ] he ain't gonna shave no two seconds off his ET... the faster you go, the more you have to do to shave a tenth... Anyway, if he's in the tens now... he ain't gonna run 8's or 9's by back halving the car... I did a rear "Back Half" suspension on a car and it took two tenths off the E.T. It went from 10.80 to 10.67 (almost two tenths) But the owner of the car can now put it in the 9's if he wants to. [/ QUOTE ] Changing the back half On a 67 Chev II and going to 15 inch from 10 inch slicks the 60 ft times went from 1.319 sec to 1.247 using the same rpm at launch with the same drivetrain combination! The ET's and speed went from 9:10 @ 145 to 8:88 @ 155 Was about 2 tenths..., and that is a lot of Speed and significant ET change!!! We Ran five seasons pretty much with consistent ET's and w/out any major parts failures! (obviously no Nitrous!) Mark
Like Sam said..., the cost for a couple of tenths of a second grows exponentially the faster ET's cars!!! That same car now runs 8.5 @ 170 with a Bruno Lenco upgrade..! $7,000 for another couple of tenths...!
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