What 5-speed for 2600+cc 250hp/260nm N/A engine?
 

I cant decide yet what 5-speed for 2600+cc 250hp/260nm N/A engine. Thinking between T1 zig zag cased with berg 5 and all weddle gears or 915 transaxle.

915 is stronger and heavier, but at almost same priceleague. Only gets me thinking that it has first three ratios quite long.

These ratios i planned first for Berg 5-speed setup:

R&P 3,875

1. 3,78

2. 2,06

3. 1,48

4. 1,04 or 1,14

5. 0,82





Most newer 915 has almost same ratios regarding R&P and 4th 5th gears:


R&P 3,86

1. 3,18

2. 1.83

3. 1.26

4. 1.0

5. 0.82


At the moment i have this donor latemodel irs transaxle with 37 spline Quaife.

http://img143.imageshack.us/img143/7341/irsquaife.jpg

exactly whats the intended use.

Street and trackday use, maybe 5% dragracing with DOT legal semislicks.

alex, if it were me and i lived stateside, i'd go berg 5 sp, its cheaper to play ratios to get exactly what you want, and lighter than 915, which for me is a clincher, tho it may be on the limit strenght wise with a 2.6, but as your not full on racing it, you should be o.k. thats my take on it anyway....

Weddle gears can be a little noisy for a daily driver. Another weak point on the type one trans is the side covers. Make sure you replace with a good solid billet one.

If your final drive is going to be a 3.88 R/P with 0.82 4th, Just put the cash into a well built VW IRS 4 speed, use the Quaife diff and save yourself a shift point. The 2.6L will have no problem pulling you thru the gears. If you are going to do a 5 speed, go with a final drive closer to 0.75 5th to justify another shift point. This is what I ended up with. I had built a Porsche 901 box. Knowing that it was going have a weaker 1st gear, I went with a type 1 IRS with heavy main shaft, 3.88 R/P, 0.82 4th and upgraded spider gears. The 2.4L type 4 has no trouble pulling the car thru the gears and is more than likely quicker without the extra shift point.

I have been really thinking about 915 box, most questions are now covered. Only problem with T1 box, even with latemodel built "zigzag" case transaxle might not be strong enough to some applications.

Even i know that these latemodel transaxles have handled 450hp honda turboengine for a while with street tires without visible or hearable damage.


Maybe if i would build smaller than 2500cc/240hv/250nm engine, then i would perhaps chosen T1 transaxle. Probably the quaife and weddle gears can handle easily more than that, only R&P weakness gets me thinking. Sure the good billet cover and weddle R&P would be big step.



It just that 915 has a lot bigger gears and ring + pinion. Early mag cased also has wey good ratios for bic cc beetle.

I first thought that i could do with 4-speed, but close ratio 5-speed sounds even better - better acceleration :)



Here is this current built transaxle what i am selling:

http://cal-look.no/lounge/index.php/topic,16196.0.html

Transaxle has been chosen, strong and smooth shifting vw bus box with berg 5-speed kit and LSD, so far only available is peloquin TBD.

Ratios will be with all weddle race quality gears and ring + pinion:

Speeds are at 3000 rpm with 265/35R18 tires:


R+P 4.13

1. 3.11= 28.28 km/h

2. 1.93 = 45.57 km/h

3. 1.35 = 65.15 km/h

4. 1.00 = 88 km/h

5. 0.77 = 114.23 km/h



http://www.thesamba.com/vw/classifie....php?id=504197

http://www.thesamba.com/vw/classifie....php?id=721145

http://images.thesamba.com/vw/classi...ix/2441032.jpg

Seems to be a great choice. Now just upgrade the CV joints to 930 Porsche to cover the weak link.