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Rear engine ideas
Posted: Wed Sep 05, 2007 11:37 am
by bru21
Building my Jimny and am about to mount the driveline. Currently I have bundera diffs, a h55f gearbox, and bundera split transfer. i would like to mount the engine in the rear if I can for a number of reasons. I am thinking of using current pajero ifs/irs flipping the diffs etc.
Is it realistic to flip bundera diffs (to get the pumpkin on the other side and the drive reversed) on a high speed car?
Is it possible to reverse the h pattern effectivly to get 1st where it should be etc?
Is there a split transfer with drive on the other side (passenger side std) that has a pto output?
Any ideas would be apperciated.
I need big travel out of this setup, running 16" shocks rear 14" front
regards
Bru
Posted: Wed Sep 05, 2007 11:59 am
by Hekta
Sounds like an interesting project. I'll look forward to people's ideas on it.
Posted: Wed Sep 05, 2007 12:35 pm
by Toy80Diesel
Sounds like a great idea but a lot of work. I hope you get what you expect out of it. My only concern would be not having the weight up front when climbing obstacles.
Re: Rear engine ideas
Posted: Wed Sep 05, 2007 1:55 pm
by Gwagensteve
I am thinking of using current pajero ifs/irs flipping the diffs etc.
Is it realistic to flip bundera diffs (to get the pumpkin on the other side and the drive reversed) on a high speed car?
Which do you want to do? either is possible with some care in oil control (slingers/scrapers)
Is it possible to reverse the h pattern effectivly to get 1st where it should be etc?
Never seen it done. might be possible with a relay rod up into the cabin pivoted in the centre- this woudl reverse left and right but not fore and aft.
Is there a split transfer with drive on the other side (passenger side std) that has a pto output?
Don't know
I need big travel out of this setup, running 16" shocks rear 14" front
With pajero IFS?? at what width? What are you doing for CV's?
I understand what you are chasing, but I don't really see the advantage. with sensible height, CV angles and width, you'll end up with about 4" of ground clearance at full compression and there will be so much custom stuff in the car you will never get all the engineering bugs out. I think you will get better performance and reliability with live axles.
Personally, if you want to go mid engine in a north south config I'd go for a subaru motor (only 2.5 cylinders long, nice and low) with a 2WD auto, cable shifted.
How about trying to set the 3SGTE back as far as possible, but front mount? (front/mid) then you can run a vertically mounted intercooler between block and bonnet catch panel- the effect on weight distribution will be very similar to rear/mid but the packaging efficiency will be better (and so will shifting, rotation direction etc...) and you will still be able to put stuff in the back.
Just my 2c.
Steve.
Posted: Wed Sep 05, 2007 5:25 pm
by nicbeer
MR2 runs mid engine but also rear wh drive. u would have to find a away to get the drive to the front.
Posted: Wed Sep 05, 2007 5:30 pm
by Red_Zook
nicbeer wrote:MR2 runs mid engine but also rear wh drive. u would have to find a away to get the drive to the front.
a 4wd rolla gear box hehe.. but they are east west...
Posted: Wed Sep 05, 2007 5:49 pm
by Dozoor
Bru What is the purpose of the jimmny , offroad racing -winch challenge ?
How much top end do you require (speed) and for how long ,
Do you need super low 50-1 -- 200-1 in crawl .
Larry.
Posted: Wed Sep 05, 2007 10:15 pm
by bru21
its for obc (ONLY NO WINCH CHALLENGE ETC) and class 8 racing. I have alrady cut the firewall away and dry fitted the motor 450mm into the cab. I just cannot sleep till i have exhausted all realistic rear engined possibilitys. obc is designed for rear engined layout. between long vertical sand winches to mud etc and every "difficult" section is a compolsory winch so there is no chance of going over backwards!
that said with the front mid i will have to figure out how to make the pedals work! looked at moving the cab back 200mm and bodylifting oit to get leg room!
Build first drive later!
the diff is forward of the motor to allow the wheel travel and this dictates leg room.
regards
justin
Re: Rear engine ideas
Posted: Wed Sep 05, 2007 10:21 pm
by largesuzy
bru21 wrote:Is it realistic to flip bundera diffs (to get the pumpkin on the other side and the drive reversed) on a high speed car?
you can do it you'll just need some kind of design to get the oil be picked up because the corwnwheel wont pick it up like normal maybe a pump or something that circulates the oil from bottom to the top of crown wheel?
Is it possible to reverse the h pattern effectivly to get 1st where it should be etc?
a custom lingage type shifter should be able to acheive this ill think more about it later. why not go auto?
Is there a split transfer with drive on the other side (passenger side std) that has a pto output?
not that ive ever heard of but im sure someone else might have
Any ideas would be apperciated.
I need big travel out of this setup, running 16" shocks rear 14" front
regards
Bru
Posted: Wed Sep 05, 2007 10:26 pm
by largesuzy
could i sudgest reading
this thread if you havent already
surely you could run a similar set up and adapt it to your needs
Posted: Wed Sep 05, 2007 11:32 pm
by Dozoor
Im thinking OBC requires rego , and if you change from front engine to rear you,ll have major engineering headaches , they,ll only wear it if you go idervidully constructed vehicle ,
Larry.
Posted: Thu Sep 06, 2007 1:57 am
by j-top paj
Hekta wrote:Sounds like an interesting project. I'll look forward to people's ideas on it.
X2
interesting to see how this turns out
Posted: Thu Sep 06, 2007 2:23 am
by Tapage
Subscribing ..
Posted: Thu Sep 06, 2007 2:27 am
by j-top paj
Tapage wrote:Subscribing ..
to this thread?
Posted: Thu Sep 06, 2007 4:11 am
by Tapage
j-top paj wrote:Tapage wrote:Subscribing ..
to this thread?
Yap .. if not I forget between many threads and forums ..
Posted: Thu Sep 06, 2007 11:25 am
by bru21
Dozoor wrote:Im thinking OBC requires rego , and if you change from front engine to rear you,ll have major engineering headaches , they,ll only wear it if you go idervidully constructed vehicle ,
Larry.
engineering is only a frame of mind. the adr codes actually cover nothing of substance. as far as i know rear engine is just an engine code - $35!
thanks for the link, amazing fab!!!
Cheers all
Posted: Thu Sep 06, 2007 12:06 pm
by largesuzy
bru21 wrote:Dozoor wrote:Im thinking OBC requires rego , and if you change from front engine to rear you,ll have major engineering headaches , they,ll only wear it if you go idervidully constructed vehicle ,
Larry.
engineering is only a frame of mind. the adr codes actually cover nothing of substance. as far as i know rear engine is just an engine code - $35!
thanks for the link, amazing fab!!!
Cheers all
yeah i know the entire thing is tig welded one of my all time favourtie rigs.
Posted: Thu Sep 06, 2007 12:58 pm
by Gwagensteve
Hey Justin -
Just set the driver and passenger back further. Most go fast motorsport does this (WRC, touring cars etc)
Also look to moving the motor to the left to free up space on the drivers side. I think the drivers side of the 3SGTE is the cold side so it should be less cluttered and easier to fit pedals around. Less legroom for the passenger, but they dont' need the visibility so their seat can go back even further and lower= more legroom. (again WRC practice) This also frees up elbow room for the driver which is a problem in the Jimny.
Steve.
Posted: Thu Sep 06, 2007 3:43 pm
by bru21
thanks mate, I looked at doing this a few weeks back when i removed the firewall. I have now fully dressed everything off the chassis (all thats left are body mounts, and 3 cross rails) and can now see how far left it can go. the drivers side is the cold sida and is also pretty naked down low on the motor. The jimny lends itsef well to sitting back as the door is so long
cheers bru
Posted: Thu Sep 06, 2007 4:18 pm
by blurredvision
Sounds like an awesome project, but if you plan on racing it in class 8 you might want to check the rules. I am pretty sure that you have to keep a silhouette of the original shape, which should be fine.
The one you might have to address is that the motor has to be in the original 50% of the car. This rules out your rear engine idea, but you can push the motor right back to the middle of the car.
Hope this helps, if you want i can dig out the exact rule from the cams manual.
Posted: Thu Sep 06, 2007 4:34 pm
by Dozoor
bru21 wrote:Dozoor wrote:Im thinking OBC requires rego , and if you change from front engine to rear you,ll have major engineering headaches , they,ll only wear it if you go idervidully constructed vehicle ,
Larry.
engineering is only a frame of mind. the adr codes actually cover nothing of substance. as far as i know rear engine is just an engine code - $35!
thanks for the link, amazing fab!!!
Cheers all
Be better if you had transfer with centred rear output
If thats the case run motor box transfer cardan joint straight to the rear irs . no need to flip anthing , would probly put the motor about midway.
Would be a pretty long front shaft !
Shifters anr,t that much of a problem , in the hardest case you would convert it to a cable shifter , easyer ones just throw some junk together
run it foward an mount it on the bellhousing if it far enough foward,
One of my JUNK yard shifters worked well.
Posted: Fri Sep 07, 2007 2:09 pm
by steel
Have you considered using a V-drive gearbox to achieve a rear engined driveline? Not sure if they're suitable for prolonged high speed use though.
Posted: Fri Sep 07, 2007 2:43 pm
by discokid
They use v drive in Trophy Trucks Im sure.
There are also trans case designs for this sort of thing. Rovacrafts new Freelander is rear engined (race car) and uses a specialised transfer case. Milners
See here
http://www.milneroffroad.com/TBOX.HTM
The reverse rotation box means you dont need to flip the diffs. But no low range
The bloody things are light though. You can pick them up with one hand
Posted: Fri Sep 07, 2007 3:50 pm
by bru21
thanks fellas! I came up with the v drive idea on the way up from briz today. thought of motor and clutch driveshaft, vdrive driveshaft transfer in std position. looked roughly at the cost $1200 - 3000 US! so i might just stick to front engine!
cheers all
Posted: Fri Sep 07, 2007 4:58 pm
by steel
Where did you price these box's? Who sells these? All my searching has only come up with some very big V-drives with integral transmission. I'm after a unit that changes direction of the drive & has a 1:1 ratio.
Posted: Fri Sep 07, 2007 5:02 pm
by bru21
was at work and searched v drives in google under images, sorry don't have more than that
I thought about making one out of a patrol transfer chain and sprockets. should be easy enough. cheap too
Posted: Fri Sep 07, 2007 5:24 pm
by steel
Hey, Bru, did you see the " Remote reverse rotation transfer box " on the Millner off road website? This looks like what i've been looking for.
Posted: Fri May 02, 2008 6:37 pm
by steel
Any progress on this project??
Posted: Sat May 03, 2008 11:10 am
by MightyMouse
Didn't see this when first posted - interesting....
Another off track suggestion is to reverse the engines rotation ( backwards cam ) - just watch ALL the auxiliaries/lube system. Aftermarket ECU and sensors won't care.
Even a transverse engine ( rotated 180 deg ) could be used - ive seen inbuilt diffs removed and drive taken off an extended pinion shaft. In fact Ive seen a FWD turned into a AWD by using an extended pinion shaft and inline clutch.
Probably too late now and wouldn't be cheap but........
Posted: Sat May 03, 2008 8:16 pm
by Loanrangie
Red_Zook wrote:nicbeer wrote:MR2 runs mid engine but also rear wh drive. u would have to find a away to get the drive to the front.
a 4wd rolla gear box hehe.. but they are east west...
So is an MR2 which would probably use same/ similar gearbox.