I know what your gonna say about the t5. Ive heard it a million times but ive drag raced 1 1/2yrs on slicks and never had a problem so............ I just want to get out of the hole a little faster when the season starts back up in april!

 

Have you calculated what RPM you will be pulling crossing the line with 4.56's vs 4.10?

 

No. I'm not sure how to do that. I know now I'm shifting into fourth not too far from the stripe. I shift at 6k. I can't stretch 3rd because it over revs it or gets into the rev limiter

 

Some would argue your current gearing is wrong.
You either want less gear so you can run 3rd all the way ( one less shift to do ) or more gear so you are pulling well into 4th across the line
Theoretically you are slowing down by having to shift just short of the line; the engine is not driving the car for the fraction of time it takes to shift
and then you don't get any use out of 4th because you are across the line before the engine is back in it's power range

What 60 ft times are you running with the slicks and 3.73's?
Do you always hook up?
If your 60's are cr*p now going to a lower gear may make then worse ( more torque from gear reduction ) plus you will also have to shift into 2nd sooner
There are situations where you can go faster with less gear rather than more ;esp seeing your max Rpm is only 6K

 

I've never ran the 3.73s. It already kind of bogs just a tad off the line if I don't keep the rpm"s at 3k. It turns a 1.69-1.72 60ft

 

I suspect with the slicks ( full slicks ? ) you would want more revs at launch because the better traction of the slicks
is going to pull the engine revs down more than say ET Streets or street tires
Have you tried launching at higher revs to see if the bog goes away ?
You gotta find the sweet spot with enough revs not to bog down but not too much that it breaks loose
(which you shouldn't do with slicks and a street 350)

 

I don't really want to dump it any higher than 3k. That's why I was thinking maybe 4.56 should get the weight moving easier

 

Yeah, I'd say more gear is required with your setup. Dig around for the calculators to figure gearing, tire height, rpms n such and go from there. You should be at top of gear when crossing trap. I'm just at 6k with a 3.73/25.6" tire in my current setup thru the traps which is perfect.

 

So are you saying something above or below a 4.10?

 

If you are suggesting that I go to a 3.73 I think that would do more harm than good. That gear from a 4.10 would only make it harder to get the car moving but harder on other things as well clutch, trans, drivetrain in general

 

No, i'm saying more gear from what you have. Based on what your saying your shifting into 4th right before traps, correct?? You should be at the top of 4th crossing the traps. More gear will help you accomplish this.

 

Yeah I'm shifting into 4th right before the 580 mark so its only trapping at about 4k and I shift at6

 

I'm theoretically thinking that a 4.56 is easier on the equipment because it gets things moving easier. Therefore not as much torque needed to move it. Some people might argue different but I'm not sure

 

580 mark?? It could help launch easier sure, but you don't want to over gear it or you will lose time there. This is a manual trans correct? What size tire are you using?

 

Sorry I meant the 594ft mark. I'm using 26-10.50-15 but if I go 4.56 ill go to a 27. Yes a stick car

 

I think you need to spray it if you're only getting just past 3rd redline.

 

That might be fun but nitrous is not consistent. Consistency is what won me my championship in 2012

 

You don't mention your trap speed so only playing with numbers here
This calculator
http://www.richmondgear.com/101032.html

has you at 6035rpm in 3rd @85mph with 4.10's ( 1.34 3rd gear / 26" tire ) dropping to 4500 in 4th.
A 4.56 ratio will put you at 5000 rpm in 4th at same speed
If you go to a 27" tire which is the same as running taller gears ( the opposite of what you are trying to achieve ) you drop back to 4800 in 4th

 

86.54 mph

 

So is that a good thing if it traps near or at the same speed?

 

Like you said, you need consistency. So if you can hook, the 4.56 will help your e.t. If you can't hook, it will help your mph (sounds like a fallacy but isn't.)

I'm aware of consistency needed for bracket racing. Are you better off being identical in consistency, but slightly faster?

 

Yes id like to be a tad faster but not have to add a cage. The reason i spoke of changing gears is because im just getting into 4th at the very end of the 1/8th and with rpms lower its hard to even play with the throttle on someone if need be due to the rpm being lower. 3rd gear just doesnt have enough. Also i figured that i wouldnt have to dump the clutch at such a high rpm to get the car moving, thus from my point of view being easier on parts! Am i right??

 

Pity your drive line isn't stronger to handle more launch revs to prevent the bog
A 27" tire with your 4.10's puts you just under 6K at your trap speed in 3rd gear

It moves off easier because you are generating more torque at the wheels at a given rpm
A 4.56 axle multiplies the engine input torque by 4.56 times , a 4.10 axle by 4.1 times

 

A 27' tire will cause it to be slower off the line with the 4.10

 

But would let you run across the line in 3rd which might make you trap better

 

Im just not understanding why a 4.56 is harder on a driveline. If it gets you moving easier then why not. I understand theres a little bit more initial shock at the launch and the drive parts will turn a slightly higher rpm but just not seeing how it could hurt if the car will hook

 

It's not harder on a driveline. It would show nominally more torque to the axles, but that varies based on which gear you're in as well. It could be easier on clutch & trans. to an extent. But it will be closer to critical driveline speed. Lots of little tradeoffs. Bottom line is if 4.10 works for you and your goal is the 1/8 (which I missed; thought you were talking 1/4) at the expense of highway drivability, then you should go for it.

 

Ok i have been doing alot of research trying to figure aout a better gear ratio for my setup. This is what i came up with....

My current setup is..

4.10s with a 26" tire
shifting @ 6k
1st gear 38mph
2nd gear 58mph
3rd gear 84mph
4th gear 113

Gear ration in question...

4.30s with a 27" tire
shifting @ 6k
1st gear 38mph
2nd gear 58mph
3rd gear 84mph
4th gear 112

Ok, you see how close together the mph numbers are. Would it make more sense to go with the 4.30 gears? Wouldnt it still pull out of the hole better than the 4.10s? The 4.56 gears put each gear down one or two less mph. Keep in mind this is for 1/8 mile drag.

 

bump

 

Anyone?

 

For sake of a argument I will go out on a limb here
You are running full slicks but don't have the driveline ( strength ) to support them.
You can't put enough power to then to prevent them boggng the car
Do you actually need them for traction?
Have you tried ; say a MT ET street slick that will hook with less torque?
Is possible a less " grippy" tire could let you launch well with less revs/ strain and as I previously mentioned
step up to a 27"tire that would let you trap in 3rd gear on your existing setup.
I see your gear change proposal as a band-aid to get around the problem of your driveline weaknesses

 

Yeah they do not hold. Been there done that. Ive had it dyno'd at 420hp

 

Actually i thought you meant a drag radial just now, Yes i currently run the et street slick

 

Also for what its worth this car has all the bells and whistles, no expense was really spared. It has a decent 60ft even off a slight bog but i know it has a tad more in it. Low 1.70s to high 1.60s 60fts isnt bad at all. Hense me trying to change a gear ratio to help out. The reason for going to a 27 inch tire is for the grip because you get a little bit more tread contact and it would help x amount of torque with the gear change

 

The reverse.
A taller tire is like going higher in gears
27" with 4.56 is as you stated similar to 3.31 with 26"

Maybe to prove your theory, you could borrow some lower tires to duplicate the effect of the 4.56 gears
without committing to a gear change first?
Bummer to waste the time / $$$ to find out it didn't do what you wanted

 

Appreciate the recommendation but i hope someone who knows a little more of what i am trying to accomplish will help.

 

Been drag racing for 30 years

 

The theory is to use short gears to move a heavy car! I know this car is every bit of 3500lbs with me in it.

 

Anybody else have any suggestions?