gisqc

Hi guys!

Currently working on my Bmw E46 race car. Plan is fully gutted, roll cage, suspension work and a Gm powerplant.

I think I figured out what I want to use as of right now... finaly.. So it should be :

-Stock LS1, going for H/C/I in the future
-Faceplated TKO 600
-Sonic/Tilton Rear-mount starter driveline package (11lbs 9" flywheel/5.5" triple disk clutch package, 11.5lbs bellhousing with rear-mount starter location)

As you can see I'd like to minimize weight at the maximum, hoping for 2700ish lbs race ready. (Means driver + gas)

So far got the car to a bare shell and started to look around for needed parts since I finaly made up my mind on a drivetrain setup.

boostnut

iTrader: (7)

Looks like you'll be able to fund the machining on that 5.3 just by scrapping all of the copper you pulled out.

rao

iTrader: (18)

Should be fun

Chicago TDP

iTrader: (3)

Do yourself a favor, sell that rock crusher, should be easy to get $1000 + for it.
Then, turn around and get a T56.
You will get 50+ MPH top end with a 6 speed and about 100 X more fun!
Trust me, I had a 4 speed and went to a 6 speed T56; more then happy with the change!

the_merv

iTrader: (88)

Ya get a T56 behind it...you will love the 2 extra gears.
Same thing I was thinking..lol..

gisqc

With fuse box I had atleast 50lbs if not 60lbs of wires and crap.... not counting engine harness in that. A lot less will go back in!

I don't have the transmission yet but I made alot of research and decided to chose that. This will never get on the street so overdrive is useless. It's also a track car so close ratio works better for me. My top speed is optimized with the rear-end and it will be set to what ever maximum I ever need on the track. Steep first gear is useless (beside paddock cruising) so actualy the 4 speed is a perfect combination of weight/gearing/price.

Project GatTagO

iTrader: (7)

If you are building a race car and don't need/want OD, then you should be looking at a real racing transmission, like a G-Force, Jerico, or similar transmission. Many can be had used for about $2000 and will have dog ring engagement and work perfectly with your reverse mount Tilton (I prefer Quarter Master) set-up. Both the Jerico and the g-force can later be retrofited with a Gear Vendors OD unit. It will allow you to split any gear without using the clutch and add a 20% O.D. for more top end.

Andrew

MikeJTR

Hi,
Looks like fun.
In order to determine if the E46 has more room between the frame rails than the E36, can you take a measurement?
On my E36, the distance between the frame rails is about 27 inches.

Thanks in advance.

gisqc

I did a quick look around and have a hard time seeing how this would be MUCH better. A used (and raced) transmission that sells atleast 2000$ (at the best) versus a rebuilt one with many many new parts for half the price. The gear ratios in the muncie are spot on for me and I'm not looking to turn into a clutchless setup either. I'd like to know why you guys would ditch that 4 speed so much tho? It's got good ratio and suppose to hold the power I want to throw at it. And it is very cheap to rebuild to.



Distance between framerails is 28inches at the front, 27.75" at the middle and narrows to 26.5 inches just before the trans tunnel starts to take form (few inches in front of firewall?)

Project GatTagO

iTrader: (7)

Dog ring transmissions aren't necessarily clutchless. You have to unload the input shaft somehow in order to shift. One way to do that is lift off the throttle and shift. Another way to do that is keep the throttle at WOT and barely slip the clutch. Try doing any of that with a synchronized transmission. I am all for the 4 speed idea. Even the T101, GF4A, and jericos will be quiet in 4th gear and have unlimited gear ratio selections.

Clearly, if you plan to use a 5.5" clutch this will be a pure race car, so why worry about synchros? Get a dogring racing transmission and enjoy. Here is a neat video of a track prepped Mustang GT350 replica. I believe it uses a GF4A transmission.

http://www.youtube.com/watch?v=5aYBB...layer_embedded

Andrew

gisqc

This video makes me drool, back to the drawings board and need to fill that wallet a little bit more... and back to hours of researching again!

gisqc

I emaild G-force about some "basic" info on Tex T101A (I think they own that now right?), but answer is being slow, so I will also ask on here.

First of all, is it possible to use a 2.65/1.79/1.38/1.0 Transmission to build a 1.79/1.38/1.15/1.0 one, reusing 3 of those gears and only buying the missing ratio? If so how much the extra ratio cost?

Also what parts are usually included in a "refresh" or "rebuild" and how much the parts cost?

chaman

iTrader: (5)

Thats a lot of....cables. Damn.

Project GatTagO

iTrader: (7)

The short answer is: you can probably get really close. Here is their gear chart:

http://www.gforcetransmissions.com/p...2007%20(2).pdf

You can choose any gear given a particular input and cluster gear. So basically you have to stay within the columns on the gear chart.

I also would never build a trans with the gears you specified. It would be a ridiculously close split between 2nd and 3rd. Remember, you are building a lightweight car with an engine that makes a lot of torque. This isn't going to be a 4 cylinder with the narrow power band. On top of that, the 1.79 first gear will be terrible for getting the car moving. If you plan on using a small diameter racing clutch it will burn up very fast because it will be so hard to get the car moving from a dead stop.

If you want nice close ratios, you can mimic a Muncie close ratio M21/22.

2.199, 1.649, 1.274, 1.000

When dealing with G-Force, it is best to call. They aren't very email friendly.

Andrew

gisqc

I will try to look at the gear chart more closely, I was just wondering if say a 1.79 ratio for first gear and second gear is same gear set or it's different to make it work. I don't have time to call much and english isn't my first language.. emails are so much easier with technical stuff.

For the ratios I'm pretty confident it's what I need, anything higher than 1.79 first (considering 1.0 as last gear) will be useless on the track and alot more prone to spinning. I'm only going to have a 4 speed so I'd like to make it 4 usable speed. than 2-3-4 are just close ratios which gets closer (makes sense, faster you go and harder it gets to accelerate). If I space them more it will just makes to much gap (notice I dont NEED to downshift everytime, I can stay in higher gear still) but when flooring it on the straight I can't have a better combination of gears anything taller and it's useless... my first is geard to be able to pull me from lowest speed (tops at 90mph, but is in powerband from 45mph) and my last is geared for max speed (should redline at ~160 or ~175 mph depending on rear-end). Rest is balanced between the 2!

Project GatTagO

iTrader: (7)

Let me try again, because you don't seem to be getting it. A trans with a 1.79 1st gear won't even get the car moving without burning up the clutch. The split between 2nd, 3rd and 4th will be completely useless.

Watch the video that I posted again. I am sure that car has a transmission with a first gear around 2.50 and evenly split 2nd, 3rd, and 4th gears. When you are racing you don't want to be shifting all the time. This isn't Forza.

Andrew

Tongboy

why the e36 diff? why not source the required rear subframe from the e46 m3 which is easily regarded as a stronger unit? you can fairly easily source the final drive options in that range you'd need as well.

good luck getting it that light - the closest right now is a done up e36 and if i'm recalling the thread correctly he's shooting for 2700lbs race weight as well and it looks like he'll make it in the e36, lot more sheetmetal in the e46 chassis...

gisqc

Maybe not with an LS1 but it's been done, few race E46's are below 2600, there's also an E36 I know of is about 2200lbs (wet i think, no driver). It can be done I'm sure, we will see if I can.. I'm lightweight driver to! And E36 diff because they are half the price of the E46 stuff when being built lsd. (Diffsonline/turner etc) And since I'll be using low gearing (2.93/3.15) it will be strong enough, and it's lighter to! Cheaper, strong enough and light.. can't ask for more!

I definitly get your point about the first gear. My point is anything higher than that (2.2, 2.5) will ONLY serve to get the car moving. It will be to low for track, if I use it I will only be spinning all over the place and when you are going slow the power will be more than enough to get you back moving. On other gears closer ratio = better acceleration on straights. Like I said, I don't need to downshift everytime to be at the exact sweet spot, so I can pull off a higher gear if needed. Now I see a few "race" trannies geared with low first, how bad is the clutch going to be hit doing this. (Getting the car moving is mostly paddock cruising etc won't be all the time for sure). I mean... (street compared) it's just like starting in second in some cars (no torque cars), or third depending on gears. Nothing impossible, now I understand they don't use lightweight packages tho. So will it be worth to "sacrifice" a gear ONLY to get the car moving when it will be lightweight (easier to get moving) and have torque?

Project GatTagO

iTrader: (7)

That's not true at all. I just punched in the info into a special spreadsheet that I have, and using a 1.78 1st gear with a 3.08 rear end and a 25inch tire, first gear will take you to 92mph at 6850 RPM. I can think of many tracks where you would want to be going around a corner at speeds much lower than 92 mph and have the ability to accelerate out of a corner.

Using the 2.20 or even the 2.5 first gear makes a lot more sense, and you'll actually be able to get the car moving without having to burn up a $1000 clutch. Small diameter clutches aren't made to be slipped.

Andrew

gisqc

True on that, but on a 92mph first gear I still get like 45mph at 3500ish rpm, which is where the powerband starts and for the speed it will still pull very hard. I'll go check numbers again see what I could do but the Muncie was at the very limit with 2.2 first gear. Actually the whole point of this convo is I have my eyes on a 2.xx/1.78/1.38/1.0 tranny and the cheapest close ratio would be the option I stated, other wise I have to redo the 3 first gear probably.