Suggest a new 3rd and 4th gear!

[leec]

My all steel oval has ran a 11.94@109.27 mph with a 2276cc motor. Wedgeports, 48ida's, FK87 and 10.3:1 cr.

When I watch the car on video there is a clear drop in rpm (out of engine power band) which obviously effects the ET!

Currently running M+H slicks (26inch?) and the following trans spec. 4.12 r+p, super beetle first, 1.48 3rd and 1.04 4th.

The winter may see a cr raise to around 11:1, what gear ratio change do you guys recomend?

Lee

ps, don't know car exact weight but it's minus interior, full chromoly cage and lexan windows. All tinware/lights/wipers in place.

[Zach Gomulka]

What rpm do you shift at? Have you had it on a dyno?

[leec]

Shift at 7200rpm, no dyno. Just tuned with an LM1

Very similar motor made just over 200bhp built by same person.

[Dougy Dee]

Classic 1.58/1.22 combo should keep things boiling at the track but screaming on the long road stretches.

[leec]

It's not a 'long journey' car

[Bruce]

Equally, if not more important would be to change 2nd gear.

[Shane Noone]

My all steel oval has ran a 11.94@109.27 mph with a 2276cc motor. Wedgeports, 48ida's, FK87 and 10.3:1 cr.

When I watch the car on video there is a clear drop in rpm (out of engine power band) which obviously effects the ET!

Currently running M+H slicks (26inch?) and the following trans spec. 4.12 r+p, super beetle first, 1.48 3rd and 1.04 4th.

The winter may see a cr raise to around 11:1, what gear ratio change do you guys recomend?

Lee

ps, don't know car exact weight but it's minus interior, full chromoly cage and lexan windows. All tinware/lights/wipers in place.

Sorry Lee ,didn't see this thgread and replied much the same on your cam choice thread,so cut and paste over to hear too

Hi Lee

Been reading this thread with a lot of interest. My friend runs an FK8 with 1.4's in his 2109 and it pulls well across the range ( he makes 170bhp at the flywheel with cooling and through muffler ). It is a full weight show and shine looker with full interior,all steel etc,a 1.48 / 1.04 / 3.88 box,I think and has a pb of 13.0 on ordinary street treads.

I have run an FK10 with 1.4's in my old 1835 which made 169 bhp. I really loved this cam combo with street eliminators 42 x 27 and around 10:1 CR and 45 DRLA's she felt really fast on the street and pulled from around 3000 up to 6500 before tailing off quite quickly.

I ran with FK89 AND 1.4's in my 2276,O44's AND 11:1 CR with 48 DRLA's and not as much fun on the street,not enough going on mid range,all top end with what seemed like a very narrow power band.

Currently my new motor is 2332 on IDA' with Comp Elims and FK87 and 11:1 and I haven't got any set time at all to give you any useful feedback except that the FK87 feels different to the 89 more streetable so far but still top endy but with a wider power band.

Can I ask about the spec combo of the 2276 motor and gearbox in your all steel Oval that runs 11's as this is my new goal too and I'd be real interested to know what combo you ues to get their ie on slicks without fanbelt,and so on. So far I have only squeezed a couple of 12.6's with belt and muffler attached but using MH DOT's so a loooong way to go yet for 11's

Cheers

Shane.

[Shane Noone]

Hmmmmmm, just thinking about your gear ratios too. It's a tricky one. I always ran stock 1st / 2nd with as mentioned classic 1.58 / 1.22 3rd and 4th on a 4.12 R+P and this does get the job done with minimal RPM drop between gears. It's like going from 3rd to 3rd again almost but with a little more pull - least that's how it feels

Now here is where it gets interesting. My old '63 was stripped out and all steel with a cage and with no concession really to lightening anywhere.
2276 with 044 wedges FK89 CR at 11:1 fully street legal running soft compound but relatively lo profile ( 205 / 60 ) Yokkie R032's out back ran consistent 12.7 with cooling on using stinger and ran 12.5 with belt off @ 106 mph.

Now my good friend Alex Noel with his similar 58 I think ( you will know the car ) ran near identical 2276 but on IDA's maybe 10.5 CR but his box was if memory serves stock 1st / 2nd with 1.48 / 1.04 and 4.12 like you. Now I am pretty sure he ran 12.3@109 mph with belt on and muffler but maybe MH DOT's ?? so you see his gears were not as close as mine but with slightly different combo he was in my mind significantly faster ........

It's hard to know what is the best combination when we all have variations on the theme with our cars. Frustrating ? Yes very at times

[Dano382]

I have the same trans gearing as well. The 4.12rp with the 1.04 (4th) is streetable. If you want less rpm drop from 3rd-4th to keep the engine in the power band a 3 & 4 gear change would be 1.58 and 1.21. Or just do the 4th to 1.21.... When Im cruzin, 4th seems good but, on the power you can tell it drops rpm too much from 3-4th gear. I did have a street car with 1.58, 1.21 combo and it was great slammin gears but only short drives in town.

Have you used CB's calculator

http://www.et-studios.com/motorsports/gears/gears.html

[DaveN]

why not ask peter at cogbox if he built the box

[leec]

why not ask peter at cogbox if he built the box

I already have spoken to him briefly, just wanted to hear what others were running.
Very happy with the box, just not sure if I should change the ratios or get a new box built by Pete.

Lee

[dragvw2180]

 My first race transmission was  geared 3.78/ 2.05/1.58/1.21 on a 4.37 Klink , then upgraded to 3.78/2.31/1.58/1.21 on a 4.37 , last was the addition of a 3.88 r/p  . I used to run 11.17@119 with that combo in my tube chassis N/A ghia. The other hot setup used to be 3.78/ 2.21/ 1.65/ 1.31 / 3.88 r/p if you had the rpm's