As much as I don’t like it, it appears most of the racing available to us is 1/8 mile.
On a little bubba and running 4.60’s, what are you using for gear ratio? My old go to of 4.10 seems a little outdated with 1/8 mile.

4.30 for sure,i have used nascar pullouts in the 4.4 range it was a rocket.

When I had my bracket dragster and was running 4.70s with a 4.10 gears everyone said I needed a 4.30 gear so I made the change, converter tightened just a bit, ET and MPH didnt change much at all, . Only thing I noticed was less money in my bank account.

It really depends on the converter. My daughters dragster goes low 4.60s @ 149 and gets to the 1/8 at 71xx rpm with 4.10s and little bubbas. As Steve said I could probably go to 4.30 or even 4.4x nascar takeouts but it's just gonna tighten the converter up and maybe get a little more aggressive in 60ft.

mine was different it definitely picked up.i cant remember the increase now but was running low 4.40s with my 5.98

I am not running a dragster so this is just my opinion.

Going from 4.10:1 to 4.30:1 is like increasing engine output about 4.9% throughout the power curve

Going from 4.10:1 to 4.40:1 is like increasing engine output about 7.3% throughout the power curve

The only problem would be if you are already maxed out with your present SLR (traction) than the rear gear change would also need a trans 1st gear change as well.

Stan

quote:

Originally posted by SP 124X:
It really depends on the converter. My daughter’s dragster goes low 4.60s @ 149 and gets to the 1/8 at 71xx rpm with 4.10s and little bubbas. As Steve said I could probably go to 4.30 or even 4.4x nascar takeouts but it's just gonna tighten the converter up and maybe get a little more aggressive in 60ft.

I don’t think I can loosen my converter any further with stator changes. And I like em loose. I will see how it is with this stair I put in.

I've tried 3.89, 4.11, 4.30 at mid to low 4.70s, i saw no real difference in ET and or MPH, did see some RPM change at the stripe, but no noticeable ET or MPH gain/loss. Possibly if your converter needs/likes the 4.30's your experience will be different than mine.

I've also made the same gear swaps mentioned above at 4.50 to 4.40 range with 250 blower on a 598 and had the exact same experience. No change in ET or MPH (60, 330, 660) but definite change in RPMs at the finish line. This converter was a tad tight for the power level so this could be some of the cause.

Good info
Thank you!

Good Morning Bucky:

Have you calculated the cost of changing a gear set lately? Parts, tax, shipping, labor plus the joy of pulling then re-installing the third member verses all the beer that money could have bought?

Just askin'

Bob

quote:

Originally posted by RPROGAS:
Good Morning Bucky:

verses all the beer that money could have bought?



Bob

^ this

I debated on posting this info in this thread.

We run both 1/8th & 1/4-mile; I'm starting to prefer 1/8th mile!

Anyway, for this year we changed from a 3.89 rear gear to a 3.55. This was one of the best changes I did with this combo. I mainly did the change to knock some rpm out of the car at the finish line & to loosen the converter up, it was a little tighter than I like.

So far, I have found pros to the change & only a slight con. Some of the pros I didn't expect.

Expected: lowered rpm & loosened converter.

Un-expected: more boost, easier to drive car, quicker ET & more MPH in both the 1/8th & 1/4. While I didn't want to go quicker or faster, I was already at the point of slowing the car.

Most of my changes are geared towards advantages, consistency & reliability to name a few for bracket racing. My performance is becoming a disadvantage & now I need to get slowed down to the sweet spot in the class.

2BKING trying to find a happy medium in his so-called advantage(s).

quote:

Originally posted by RPROGAS:
Good Morning Bucky:

Have you calculated the cost of changing a gear set lately? Parts, tax, shipping, labor plus the joy of pulling then re-installing the third member verses all the beer that money could have bought?

Just askin'

Bob

Thankfully I really don’t drink much nor ever put pen to paper when it comes to racing costs. Lol
Particularly when bracket racing in the mid fours with a small block. Practicality kinda flies out the window

quote:

Originally posted by Bucky:

quote:

Originally posted by RPROGAS:
Good Morning Bucky:

Have you calculated the cost of changing a gear set lately? Parts, tax, shipping, labor plus the joy of pulling then re-installing the third member verses all the beer that money could have bought?

Just askin'

Bob

Thankfully I really don’t drink much nor ever put pen to paper when it comes to racing costs. Lol
Particularly when bracket racing in the mid fours with a small block. Practicality kinda flies out the window

Oh and if alcohol ever gets in the way of racing costs I’m checking into rehab!!

But Bucky....... ALL that beer???

REALLY?

Bob

i,m with triple nickel ... wore out dial mics on gear changes and see vey little. spend your money on HP...

My experience from 4.10 to 4.30 and back to 4.10 was minimal. I believe the key is a good loose converter to keep motor in its powerband.

In the past I always geared combination for the 1/4 mile. Now everything is 1/8 mile racing here in Texas except for NHRA National and Divisional events which has its own problems.

Bucky, I would be surprised if you had to change the gearing at all. It’s what the tire and car want without having to run a timing curve for tire management. You have hair dryers! Your rpm graph should pretty much be a flat line with a little bump in shift. Not saying a timing curve is not the way to go for some especially with tire limitations / track conditions and excessive power.

JMO.

This message has been edited. Last edited by: BP758,

I think I finally got a consensus answer that I ask someone when they say they are changing to an 1/8 mile gear.
My question has always been "if you get your best reaction and 60ft with X gear what do you hope to gain?" I never get an answer.

I leave the gear that's in it, in it. I don't see a reason to change if the combo is working well and dialed in. I seriously doubt there is enough difference in performance to justify the change.