Choosing a Tranny

Cpt Zoomy · Post by **Cpt Zoomy** » Wed May 16, 2001 11:05 pm

I am at the point with my car that i am choosing what to use for a tranny. I have thought of using a type 2 68-72 tranny or a bug irs. Any suggestions? The engine it will be coupled with is a 2443 (88x94) with 48 ida's
Thanks in advance.

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1/4 in 11's .... no problem.
http://www.sgvwa.20m.com

Post by **Tom Notch** » Thu May 17, 2001 5:52 am

You need to define what your use of the car will be. A bus box has gearing more suited for a baja bug or drag car than a street car. A Berg 5 would be nice or a Porsche 901 would be, too. A close ratio 4 spd T1 would be a bit short geared for freeway travel.

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Tom Notch
Tom's Old VW Home

Cpt Zoomy · Post by **Cpt Zoomy** » Thu May 17, 2001 12:42 pm

It will be strictly for drag use. It's my first attempt at a drag car so i am unsure of what would be best. I believe my car doesn't have the cooling to be streetable.

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1/4 in 11's .... no problem.
http://www.sgvwa.20m.com

Muffler Mike · Post by **Muffler Mike** » Thu May 17, 2001 2:20 pm

Drag race only
Go as short as reasonably possible with out running out of rpm.
This kind of means you need to figure out what your motor is capable of.
Find some one who has a similar combo that works and maybe make up some ratios that will match or come close if you want to use a bus box.
Keeping in mind weather your cam can take rpm drops from gear to gear, etc. Ex. My aspirated ratio had a short 3rd but a fairly big drop to 4th, but having a mild motor, it didn?t hurt it too much when dropping below 5000rpm.
You might be looking at some trial and error, how about tell us about your motor a little more, car weight +you too. Some one might be able to choose something a pretty close to start you out.
lets say you had some massaged superflo's with fk89 cam with 11-12:1 cr and put out say 230 hp. peek hp probably somewhere in the neighborhood of 72-7400 probably shifting closer to 8000. 230 hp will push a 1650 lbs car into the lower 11's at 115-120mph. a 3.88 r&p with a 1.31 4th and 26 tall tire should be good for about 122mph at 8000. obviously all hypathetical. but one way you can look at it.

Muffler Mike
www.MufflerMike.com

[This message has been edited by Muffler Mike (edited 05-17-2001).]

Cpt Zoomy · Post by **Cpt Zoomy** » Thu May 17, 2001 5:05 pm

It never ceases to amaze me how willingly people help out people when it comes to vw's!

Ok my car is gutted of all interior, except instruments and fiber driver's seat. Has a 5 point cage, and has a fiber glass front end and rear lid. I don't know the weight yet as it is just going in for paint and hasn't been assembled yet.

My engine comprises of an 88 scat crank, carrilo h-rods, fk 8 cam, mahle 94 pistons, superflow 48x37.5 heads, weber 48 ida's with berg linkage.

As i said before i am only intending it for the track and unfortunatly of all the people i know in my area it is one of the larger engines around. So info is hard to come by.

Thanks tonnes for the help mike!
James

Hot Wheels · Post by **Hot Wheels** » Fri May 18, 2001 6:57 am

For what its worth i run a 5 rib bus in my sand/asphalt drag buggy. Last year i ran the 2274 type 1 motor launched at 6K shift at 8 to 8500 rpm. We run 1/8 mile here so i dont get into 4th gear. I put in FTC gears and i dont remember the ratios but we changed the first gear to a ratio close to the stock second gear and then used close ratios on 2,3&4. I run 27" tall 8" wide slicks and 13.00 plus paddles. I also use sway away axles and 930 Cv joints. Three years of abuse and no breakage yet.

My partner in crime just put his third trans in the beetle swing axle car. he upgraded to a race case this time. Broke stock bug cases regularly. He runs a 4.37 ratio and smaller tire. He also runs 8.0 where i ran 8.4 last year. His is a bit lighter and an asphalt only car.

For me durability is the reason i like the bus. I have better things to do than rebuild trannies. Overkill is the standard.

Sean

Muffler Mike · Post by **Muffler Mike** » Fri May 18, 2001 7:57 am

Well I can see for an honest 200 hp from what you have.
And with the k-8 its all over at 7000 rpm in other words you will probably find shifting at 6500-7000 would produce the best et?s.
Lets say your car with you in it comes out to 1700 lbs. 1500-1550 car by it self. Maybe less.
That should be good for some hi 11?s at 110-115 mph.
So if it was me and I wanted a top of the line type 1 box, I would personally start out with a 3.88 r&p 4.11, 2.35, 1.70, 1.21 this will put you in 4th at about half track shifting close to 7000 and then you are along for the ride the next 1/8 mile. And with that k-8 you can take the big drop from 3rd to 4th.
And if you wanted a bus box, (which im not to familiar with.) I think you can get them with a 4.80someodd ring and pinion and you just have to figure out the final ratio. Lets say it comes with a 4.86 ring and pinion, you would need a .97 fourth to match the type 1 box set up I would want.
Hope this helps.
Good luck

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Muffler Mike
www.MufflerMike.com

bruce · Post by **bruce** » Fri May 18, 2001 9:43 pm

If you're building such a car, presumably you've been out to the track in Mission. Have you seen the blue tube frame oval running in the 10.90 index class with all the V8s? That's Terry Hoogstins. Talk to him about a gearbox. He has spent the last 15 years trying to break his own, and knows what doesn't break. Get him to build it for you. You'll save lots of money having him do it. Do not go out to the 'wak to get it done.

Cpt Zoomy · Post by **Cpt Zoomy** » Fri May 18, 2001 11:12 pm

So would a swing axle be stronger or irs? My pan is swing but it wouldnt take much to change that.

flying tomato · Post by **flying tomato** » Sat May 19, 2001 9:41 am

Here's a gearing calculator that was posted on this forum a while back. You can download it and it and compare combinations. http://www.geocities.com/MotorCity/Garage/1811/

If your car is light enough and you have good air like Mission raceway and you have higher compression and are making big power then maybe... with a type 1 you could handle the 3.88 rp with the 3.78 1st, 2.31 2nd, 1.58 3rd and a 1.25 4th or somewhere in that range.

The bus box with the Folts axles is going to be stonger and more expensive. That's what I run and I have had 7 years on my last bus box, no problems ever. I took it out just to make a gear change. The bus box will also reguire the Berg bus into bug adapter, shift just like a type one but gives you the larger Bus ring and pinion.
My old bus box was tight with a 4.86 rp, 3.55, 2.06, 1.43, 1.09. Worked well with 200hp in a 1950lb bug with driver.

Now I have a little more power so I'm trying a 4.57rp 3.30, 1.93, 1.35, 1.04.

Get an ERCO catalog and you can see the availability and cost of all your tranny bits.

JohnConnolly · Post by **JohnConnolly** » Sat May 19, 2001 7:22 pm

Your cam is too small with that engine.

Cpt Zoomy · Post by **Cpt Zoomy** » Sun May 20, 2001 2:10 pm

Why do you think my cam is to small? What do you recommend?

Post by **Tom Notch** » Sun May 20, 2001 9:50 pm

A fk 87 would be nice in that combo and then step up to an 89 in the future. Once you get the car dialed in and learn the ropes driv'n it, the step up to an 89 would be easy. and add at least another 2 tenths. the 8 is a good street cam but would really stunt the power output of what you have. One other choice could be a web 86c, just a bit less than an 87. Strong runner and pulls like the dickens from 4000-8000.

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Tom Notch
Tom's Old VW Home

Bruce M · Post by **Bruce M** » Mon May 21, 2001 7:01 am

Has anyone considered using the 5spd Type25 bus box, are the ratios to low for good street use or is it just too big to fit in even a modified floor.
Or is it just noones considered it?

JohnConnolly · Post by **JohnConnolly** » Mon May 21, 2001 2:05 pm

I recommend the b for many engines for street/strip. If you want MORE, go with the C, but you start losing manners.