transaxle dimensions??? help needed

[andrew]

i am planning out a kit car with a mid engine setup. im planning on using a gm ls3 engine which is rated around 430 hp/tq. before i actually buy anything i wanted to have the entire thing blueprinted. i have been recommended a lot of different transaxles mostly the g50 types but still encounter a ton of issues most of which is lack of available info. i am in particular looking for l x w x h dimensions and end of motor end to output shafts measurement?

sorry about that 4th grade description in the last sentence im not very technical with this stuff but i am learning. anyways other things to note is i think a 6 speed would be best because i want this as a daily driver and paired with a big v8 like the 6.2 ls3 is it would be advised and practical to have a very nice overdrive gear for the long highways. daily driver also means it needs to be acceptable noise wise, usability, and especially durability. this is 2010 with engineering capabilities these day this stuff should last at the very least 100k miles before a rebuild or such things. but in the time that it will need to be reworked i would prefer a larger older supplier because they have the pretty much assurance they will be around to supply the parts.

as mentioned i am learning and that said i have no idea what to look for in gear ratios. complete greek to me. also i would like this car to be able to handle tracking/autocross say 2-3 times a month. other notes. the corvette with this engine does 190 mph i was really hoping thru gearing and better aerodynamics to get to the 200 mark after all bmw is getting there with v8 with 400 hp and a 7 speed but again bmw is very well made. also the lower the engine can be mounted the better and i understand the transaxle affects that in some way. hopefully below $15k (you can get rebuilt or pretty close to new g50's off ebay for like 5k whic is nice) as if i was trying to spend $20k plus i would opt out for xtrac since they are supposed to be ridiculously good. another thing i have noticed is that these g50s are all re manufactured i would absolutely prefer something brand new

the shorter the area from output shafts to engine side the better since that means i can move the engine further back thus giving me more cockpit space. i already have the dimensions for track wheelbase and a few others and would like to keep the whole thing rather compact.( i already had to make it bigger to make sure i have room for ppl and its still i smaller car).i am unsure of lsd so i dont really know if i should be asking for a built in unit or not?

anyways sorry i know thats a long post but hopefully that covered just about everything

 

[andrew]

oh yeah and H pattern shifting.

 

[Terry Oxandale]

There is a ton of information about the 930 dimensions in some previous posts, a bit less on the G50. I believe they are very close to the the same dimension from bellhousing face to center of output shafts, which for the 930, is just about 9" for the long housing (30mm less for the short). The inverted cases on both will have the typical "H" pattern with the 930 four-speed, and of course, the additonal gear(s) tacked onto the pattern for the G50.

 

[domtoni]

Try this:

http://www.gt40s.com/forum/gt40-tec...w-transaxle-comparison-discussion-thread.html

 

[andrew]

i heard that the porsche transaxles are crap for ratios when paired to the v8s and that their 6 speeds are even worse than the 5s.

hi dom actually i had read that entire thread and saved the last updated files. it really is a great source of info in one place with some very very hard to find info. so a big thanks.

ive had my eye on that zfq from quaife because the thing is excellently compact compared to those other ones. really the only other one i was interested in is the gt2 getrag one which is a 6 speed but i am guessing that has too short gearing. and at $11k that is one of the very few on that list that actually seems like they are worth the price you pay really most of these things seem like such a ripoff i really doubt the thing is that much harder to make than a standard transmission

so zfq perfect in almost every way and likely built for a v8 too as in the right gearing? hmm one flaw i was looking at and it is kind of a big one its a 5 speed. dont supposed by now they offer it in a 6? and also i was trying to find it in quaifes catalog but zero luck is it no longer offered or something?

:furious: quaife should make a 6 speed for like $500 - $1k more and it would be perfect.

 

[andrew]

hmm maybe i read the chart wrong. does any one have a blue print drawing or more information on the quaife zfq 5 speed H pattern?

 

[Russ Noble]

i heard that the porsche transaxles are crap for ratios when paired to the v8s and that their 6 speeds are even worse than the 5s.

Compared to what? And why?

Turbo boxes, G50/5x should be pretty good. 930 in many ways even better. If you've got a V8 why would you even need a six, or five speed? The 930 four speed has ideal ratios for road use behind a V8. IMO.

If you find Porsche ratios are not so good for autocross then you can always change them to suit. That will affect your daily drivability. But in the lower gears tyre adhesion may well be your limiting factor rather than inadequate gear ratios. You have conflicting requirements that you may need to resolve before you can make a decision.

Maybe a five speed G50/52 would work well for you? 1st I would imagine would be too low for autocross but give a nice drivable gear for road use. 2nd, 3rd, 4th are probably all you need to use for autocross (not that I'm at all familiar with autocross) and 5th should be your nice cruiser.

I think you need to do some homework, there is lots of info all over this site. And sort out in your mind what your real requirements and priorities are.......

 

[andrew]

Renegade Hybrids just look at, for example, under kit cars and transaxles g50 90+ and the g series 6 speed. that is the only place i bookmarked because it was a possible supplier. i have read in a few other threads i forget where and what websites/forums that there are complaints about the ratios.

the main reason for 5 or 6 speed is higher top end and lower cruising rpm thus less gas used/ engine working less. so really all around its a pretty good thing. just about the only downsides of them are longer boxes more weight (not much though) and a bigger price tag.

another thing about this whole thing is i would really really prefer a transaxle that comes ready to go. brand new not rebuilt and without me having to mess with the ratios. really all i can find is rebuilt unit from porsche. within a few weeks im planning to make a trip to a porsche dealership and see what they charge for a new box. (im sure it will be outrageous just because they like to upcharge for their name.)

really does anyone have info on this zfq from quaife? it looks wonderful i hope they still make it.

agreed on me needing to do homework 100%. i want to have zero surprises building this thing if i decide to go thru with it. speaking of homework does anyone have any threads or other websites for good learning information about tranny ratios?

 

[Keith]

As far as I know ZFQ very much still available as they are going in all sorts of mid engined cars. The reason you can't find them on their (Quaife) web site is that they are produced for/with GT Transmissions Ltd.

Looky HERE for contact details.

Hope this helps..

 

[Seymour Snerd]

ive had my eye on that zfq from quaife because the thing is excellently compact compared to those other ones.....any threads or other websites for good learning information about tranny ratios

If you're considering the ZFQ you also should look into the "original" ZF, which can be had as a 6-speed.

RBT Transmissions

Choice of transmission ratios has been discussed to death on this forum. Look around.

 

[paolo]

search mendeola and ask for dwight you need the sdr transaxle brand new 5 or 6 speed $10k ish