6G Celicas Forums

ok i am posting here since there does not seem to be another place to post this unique prospect. i do not want to hear answers like "you can do anything with enough money", or "not worth it" or "why do it" or anything along those lines.

What i would like is your ides on the serious prospect of how this can be done.

there would be two major parts to the project to addressed. once a suitible power train was settled on.

chassis preparation.

drive train and suspension preparation.


as i have been day-dreaming over this possible project there are a few things that right off the bat there were evidently nice about using a markII chassis as a basis for a poor mans Lamborghini. mainly the chassis, and the fact that the car shares so many parts with the GT4.

starting at the front we have the open area of the fronk, and an open floor with easy access. this would allow for any chassis re-enforcement or bracing needed to mount and hold the front diff, an easier prospect. moving along there is the central tunnel that gas tank sits in, that (after the removal of the stock gas tank) would be perfect for the drive shaft pass through. After that there is the fact that, that tunnel opens up into the engine bay with a cone shape opening that may give way to a bell housing with out much massaging.
the engine bay its self is self-explanatory. and last but not least there is the the fact that the trunk is a nice open space that is located within easy reach of the engine bay. ready to take on any spill-over from the engine bay, or to take on any supplemental systems that must be placed in the trunk to clear room in the bay. Other than the modifications necessary to mount the front diff to the chassis the rest of the drive train should just bolt right up to the bolt points between the swapped knuckles and the MkII's struts.

As for the drive train there is the very fact that the MkII's turbo trans and the GT4's trans are pretty much the same thing. i know that there are a few differences on the axle lengths between the celica and the mr2. but those are issues that have already been resolved a number of times over. the most likely custom part on this would be the central drive shaft. of course the orientation of the entire power train would be inverted/ spun around. so new motor mounts. the biggest issue is the fact that the wheels would essentially need to be spinning in revers with 5 revers gears and one forward. compared to the regular orientation of the GT4's i don not know if there is a way to modify the trans to allow for this to happen, or if there would be the need for a number of custom gears or shafts. or what not.. i do not have allot of knowledge of the inner workings of a trans. but there must be a way to get this to work.

Passed that, there is a placement of the now removed fuel tank, with a fuel cell up front, set as low in the fronk as possible to help keep the now upset and higher center of gravety, as low as possible. this will also allow to better balance the F/R weight distribution.

Hell, once all of that is sorted the rest is simple plug and play. especialy of the starting chassis was a turbo model to begin with.

IF the GT4 drive train can be used, my ideal setup would be to use that, mated to a 2grfe. amd maybe later a turbo slapped on.

There are other options to consider though. the first thought i had was to use an 04 STI power train. it would provide a better and lower center of gravity, a 6 spd trans. beefier hub/knuckles, and an active center diff to boot.. the width on the wheel base should be close enough to not need to use custom axles, with out having a drastic effect on the rest of the suspension geometry. the rear hubs should bolt right in to the MR2's struts and the two lower arms as well.. there should not need to be much modification on that end if any. not sure about the front. though using this platform also has its downfalls.. due to the orientation it would be more of a rear engine. the rear firewall would most likely need to be removed to fit the motor right. and the center tunnel may need to be enlarged as well.

There is also the idea of using an Evo 8/9 power train. this should allow for a similar mounting to the original engine position.. mounts will have to be custom of course. but the simple fact that the mivec 4g63 can handle approx 450whp reliably before needing any major work, is a big plus. the drive train can handle a good bit as well, the center diff and engine both have ECU's that can be easily accessed and tuned. as for the rest i am unaware and unsure.. i have not spent enough time under an Evo to be able to make any measurements or comparisons.

And of course any of this rests on the assumption that there is a way to modify a transmition to inverse the rotaion and its gear orientation (5/6 revers and 1 forward, compaired to its original set up.)

so please, discus, theorize, point out what may or may not work wile working to get this project realized. what sort of specific issues should or may need to be addressed? but be sure that no mater what you say, it is done so with a constructive tone.

thank you.

Sounds to me like you are complicating the transmission issue- think about it. The MR2/Celica/Camry all use the same transmissions and they aren't geared differently. Otherwise, good luck

this needs to go either in off topic, or mr2.com

there are only a few mr2 owners here and couple of fans.

and it wont work, because its rwd, and if you put the engine in the front, then defeats the point of an MR2, sorry.

yes i have it on MR2OC.com
and i posted here since the most of parts woudl come from a GT4, and yes i have also noticed a number of members who also own MKII MR2's..
and i don't think you read my post fully. the idea would be to place the motor in the same spot, but have it mated to an AWD drive train. essentially having the whole power train spun around 180* (compared to the celica). the only real question here is how do you get the trans to operate in revers? in essence needing 5 back and 1 forward. (again compared to the regular celica orientation)..

but thank you for your post.

Perhaps this helps

i guess you missunderstood my post, "it wont work because of RWD". i did not need a drawing to understand things either. but it sees you took your time. that is appreciated

but let me explain with detail my post.

Like you stated, where would you get the transmission? i dont think it exists, most AWD trannys are set up for front placement and the transfer case goes to the back to power the rear tires.

i read

you need a forward facing transfer case but in theory with "money" you can build your own transfer case. But you dont want that answer, thats why i did not post it early

i read

again "the transfer case situation" is the part you need to overcome.

i did not say "it was not worth it" or did not say "why do it", I said it wont work

hence your words



So i just followed your post guidelines, and theorized my point of view. Not being rude, just stating facts.


so unles with money you build a forward facing transfercase, or find one thats already invented, i just dont see how it would work.

post ur mr2oc link

would seem that i did misunderstand.. i am sorry..

and indeed the issue is the trans/transfer case.


the link

many have asked the question.

read the bottom of the page..


http://www.groupbrally.com/toyota.shtml

its an MKI that is rear engine and awd, built by toyota, custom tranny, with unk location

Yes interesting.. i had read that page when i was poking around the web wile typing my initial post. defiantly interesting. but those cars were more celica, than MR2 and also had a number full on custom parts..

As i had admitted on my initial post i am not very well versed on the inner workings of a trans. but it would seem that if there was some how a way to add an other gear right off the input , then go to the actual input shaft. then that would be an easy fix.

unless you put an r8 tranny. you have to make a custom one.

really intresting idea man. curious to see what you dream up.

from what i remember from a lecture at JSC a while back, the first (maybe only) application of a forward facing transfer case is an electric rover designed by nasa in the 70's. i think i remember them scrapping that design for one with a pair of smaller motors running each axle

theres an AWD supra that uses a takeoff from the diff back to the front wheels. you may want to look that guy up and see who did the custom work

also read an article about an awd fiero a while back. you should look into that guys build. if your willing to cut the frunk up a but you might e able to pull off something similar using 2 motors (1 electric) to indipendantly run each axle

as far a as a discussion goes it very intresting to me, and i think would make a cool project. I personally dont know of any configuration that will allow you to use off the shelf toyota drivetrains in a configuration that makes what you outlined in your diagram possible.

i hope this was some help. please post how it goes

peace

-jec


found it

http://grassrootsmotorsports.com/forum/grm...id/10519/page1/

This post has been edited by JasonTX: Feb 4, 2012 - 11:31 AM

Xtrac doesn't do little boy parts, they do big boy stuff. That costs big boy money, you're talking upwards of $20,000 for the transmission, $10,000 for the differential, etc. Probably even more if they have to design the parts as well. $50-70,000 investment into JUST the drivetrain. Go buy a car that's already AWD and make it run 10's for that price.

http://www.xtrac.com/# Notice, they don't list prices. A little google search, a standard sequential FWD trans from them starts at $18,000. You want something for AWD.

I did a fair bit of delving into on this same concept a number of years ago and came up with many wacky ideas, but they do all seem to depend on the gearbox issue.

Stuff like: The gt4 box not running backwards as it stands.
It has an oil pump internally that wont like working in reverse plus the direction of back thrust from its helically cut gears may create issues with wear and gearshifting problems.
That in itself could possibly be overcome with some kind of controlling washers inside.
I had the idea of running the engine backwards to facilitate the use of the gt4 box in that rear mounted mr2 configuration, however, again, youre into issues like swapping all the pistons around on their rods as the thrust direction changes (pistons generally have an offset to the wrist pin which wont work so good the other way), oil pump wont work so need an electric setup, camshafts need a regrind to alter opening and closing ramps (unless symmetrically ground), cambelt tensioning can be taken care of with a tensioner on the other side of the belt ( unloaded side),..... lots of small stuff to work out but i always look at it like this: most anything can be accomplished with human ingenuity, oh and deep pockets!

thought:
What if you removed the internals from an e153f to give you the awd case. Depending on similarities between the transmisions.... you then put 90% of the mr2 tranny guts in the 3153f (assuming you could get them to mount), because they already spin the right way, and come up with some custom way to get the driveshaft to spin?

the problem with the awd tranny is the position of the transfer case



it sits behind the engine.

a front facing transfer case is whats needed. hence custom tranny.

flipping the tranny gives 5 reverse speeds and 1 forward. kind of difficult to overcome that.



this is what u need. but it will cost ya!!

nice example... that's a hot car.

It's a shame this is so difficult/impossible.... because imagine the machine you'd have on your hands if you could pull it off..... omg.

Because spaceship.

Too bad you couldnt gut a gt4 trans then find a housing that is mount on the oposite side of the engine as the gt4 trans
An have it modded to hold the gt4 guts an bolt to the 3s

If I was to design a awd mr2, i would do the most cost effective approach.


Instead of re-inventing a transmission or spinnning the engine backwards. I would install the gt4 transmission into the mr2. With the now rear ward facing out put shaft, i would get a cnc shop to help design a transfer case that will bolt on to the gt4 transmission that will drop the drive shaft down and facing forward

.

Imagine the output shaft from the transmission connected to the top gear. And the drive shaft to the front wheels will be connected to the bottom gear. This custom transfer case would drop the power lower and under the engine with a small drive shaft similar to how the Audi r8 drive shaft. Basically you are transfering power down and under the engine to the front wheel.

You might have to space the engine mounts higher to give you more clearance for the drive shaft. This way your adding to an already well built engine and transmission system versus completely redesigning it.



i decided to help illustrate my idea with some state of the art cnc metal works images:



the red arrow points to where the custom gear transfer case will bolt up. The white thing is the flange that lets you bolt up the front drive shaft.

This post has been edited by Hanyo: Feb 5, 2012 - 8:39 PM