Working on new dragster build for super comp and bracket racing with 615 SR20 BBC. Looking for feedback on people running or tried both 4.11 and 4.29 rear gear with big tire. I can do the math on rpm difference, but looking for real world feedback from the forum. Thanks.

4.29 minimum

For who'm it may concern,,,,, The "throw the kitchen sink at it" new Big Bubba 2.0 Radial doesn't grow.

Agree with Ed, 4.29.

4.11 will be slower/calmer

I went from 4.30 to 4.10 No et loss at all….so I say converter was the factor…definitely calmer which is needed in certain times of the year I’d go 4:10…IMO

Yes, you have or had the wrong converter

Going teens, 4.20s and 30s I think the 4.11 wwould be preferred.

Avg 615 SR20 will/can run 40s most of the year, for those reasons I like the 4.29

You can cross 7200 rpm's at 158 mph with a no tire growth new Big Bubba radial 2.0 in conjunction with a converter that slips 10%.

I think 12 - 13% is probably more realistic though, maybe more.

When you go to a no tire growth radial, everything you think you learned with tire growth kinda goes up in smoke, because the exact amount of tire growth in play is unknown.

I moved 3 different gear ratio's in and out of my rearend housing last year discovering this to be true, on a radial.

Take it for what it's worth, everyone gonna be on Big Bubba radial 2.0 when it hits the market, from what I hear.

You can throw the kitchen sink at it no problem.

This message has been edited. Last edited by: Mike Rietow,

quote:

Originally posted by TORQIN:
Going teens, 4.20s and 30s I think the 4.11 wwould be preferred.

Avg 615 SR20 will/can run 40s most of the year, for those reasons I like the 4.29

This slow like ED go 4.30…fast like TORQIN,LEMEN an WHOMP go 4.10

Big Bubba radial 2.0 looks pretty cool too, I think.

I have a video of a 4.40 car going down on it, but have been told don't make it public.

I can tell you what I was told though, it's a BMF.

4.29 in super comp it will be like a rocket when stop goes off

quote:

Originally posted by Mike Rietow:
Big Bubba radial 2.0 looks pretty cool too, I think.

I have a video of a 4.40 car going down on it, but have been told don't make it public.

I can tell you what I was told though, it's a BMF.

Good news! Hopefully they hold air

LOL - I got 4.56's !

So does a good friend of mine.

Scott…KNOWS and there ain’t nothing slow about my dragster!

quote:

Originally posted by DragRaceSolutions.com:
LOL - I got 4.56's !

Well you’ll be taking TIMING out of it….if you plan on 4.20’s

I've been running 33.5" tires with a 4.11 forever. I'm switching to 34.5" tires this season and debated moving to 4.29 at the same time, but I'm going to stick with the 4.11 to start.

If I was 1/8 mile bracket racing, it would be a no-brainer to go up with the gear but I'm primarily running 1/4 mile Super Comp. Currently coming off the stop in Low gear and shifting/trapping both at 7500 with a conventional 632.

quote:

Originally posted by WHOMPWHOMP:

quote:

Originally posted by DragRaceSolutions.com:
LOL - I got 4.56's !

Well you’ll be taking TIMING out of it….if you plan on 4.20’s

I think Scott has a 1.58 low gear set in trans? Could get away without pulling timing?

Even the 4.11 gear requires pulling timing at times going:

.987
2.739
4.225
165.10

Btw the engine that ran this in Cory's dragster 2 months ago is currently for sale...(cheap plug)

i ran 4.44 nascar pullouts for a while worked really well for 1/8 and super comp

quote:

Originally posted by TORQIN:

quote:

Originally posted by WHOMPWHOMP:

quote:

Originally posted by DragRaceSolutions.com:
LOL - I got 4.56's !

Well you’ll be taking TIMING out of it….if you plan on 4.20’s

I think Scott has a 1.58 low gear set in trans? Could get away without pulling timing?

Even the 4.11 gear requires pulling timing at times going:

.987
2.739
4.225
165.10

Btw the engine that ran this in Cory's dragster 2 months ago is currently for sale...(cheap plug)

No wonder his stuff wouldn’t run lol…lol…

quote:

Originally posted by TORQIN:

quote:

Originally posted by WHOMPWHOMP:

quote:

Originally posted by DragRaceSolutions.com:
LOL - I got 4.56's !

Well you’ll be taking TIMING out of it….if you plan on 4.20’s

I think Scott has a 1.58 low gear set in trans? Could get away without pulling timing?

Even the 4.11 gear requires pulling timing at times going:

.987
2.739
4.225
165.10

Btw the engine that ran this in Cory's dragster 2 months ago is currently for sale...(cheap plug)

For sure