hi every one this is my first post on here i have just got my new lump for my imp a gsxr1000k2 need help with whot diff to fit eg xr4x4 or freelander do i need lsd or not? also whot ratio is best for the job? also will need shafts modding from imp to ford ect eny advice would be good thanks paul

Hi Imp!

I've a GSXR1000 K2 in my MK Indy - good choice!

I've a LSD XR4x4 on mine but I've heard a Freelander is better. XR4x4 has better acceleration (ratio around 3 I think?) but 70 mph in 6th = 7000rpm!! Bit noisy and affects my top end too. Freelander is much better for this I believe - 70mph is 3500 to 4000 I've heard.

Hope this helps a little - You'll remember the first day you appreciate the performance of your engine!!

All the best

I used to race imps!!!!!!!
You will probably need an xr 4 X 4 diff if you are racing as it is limited slip (clutch type). I am guessing you are using a chain drive?
I have bought one for my next R1 powered project from another locoster.
The advantage is that a simple change to the cog on the diff, will adjust your gearing for long or short circuits.
I used to change gearboxes for races!
I would also consider seriously uprating your wishbones, drive shafts etc.
A 998cc engine used to put out around 120 bhp, although the driveshaft donuts may be better for a bec on take up of drive.
Good luck, and please let us see some build photos!

[Edited on 14/9/2006 by nitram38]

hope you like pic of imp in pics cheers paul ps thanks for your help my imp is stript out to the max. should be approx 550 kg or very nere allso engine will live in the rear with small prop to ford diff or f lander hope this helps most imp racers get down to this weight

[Edited on 15/9/06 by imp paul]

[Edited on 15/9/06 by imp paul]

cant tell from the pics is the engine going in the front or back? as you were asking about diffs i assume your front mounting it and driving through a diff as most sevens do. the freelander is a 3.21 ratio and non lsd unless you want to use a quaife atb and will lower your cruising rpm by700rpm compared to a 4x4 diff with 3.62 ratio.

hi imp paul

I looked at doing this fitting a bike engine in an imp thinking it would be wicked

thing is personally having already owned an r1 BEC

this weighed 460kg wet weight
and was fantastic

But having done some research etc

youd be lucky to get your imp weighing under 640kg

so thats going to be quite a weight to pull

it would still be quick but no quicker than a good hot hatch car and you would end up dissapointed I think

because my car 460kg

plus me 110 kg = 570kg = ballistic car


570kg plus passenger of 70kg

= 630kg and the car was still rapid


but the was a breaking point and I feel that was a slightly heavier passenger

another person about my weight so the car would be over 650kg

they still thought it was quick and it was but as the driver I could really notice the bogging down less power through the rev range etc


so take in my mind you car is already going to be around the 640kg without any drivers

I could be wrong but this is the reason I got the metro which now weighs about 720kg with a bit of stripping

and has the 160 vvc engine

if you had a spaceframe imp you would be laughing as these weigh very little

hope that helps but dont let it put you off

thanks chris

my imp runs on 175 50 13 tyres .so which diff will give approx 125mph top end and good pick up. ? 3.38 or freelander 3.21 ? allso can you turn f lander diff to run up side down ? as in a imp it will have to be turned faceing backward. and turned 180% to give forward movement cheers paul

You want to be looking at keeping the engine in the same orientation as in the bike and run it through a chain driven diff. Turning it 90* and running with a prop will put the engine in the wrong place in the cabin and take a lot of fabrication plus the ratio problem can be cured with different sprocket sizes.

I think that there is no added value in putting the engine in the same direction as the bike. In cars, bike engines have to take acceleration in all 4 directions, which they don't have to take in a bike (only front to back). By putting the engine in the same sense as for the bike you aren't gaining anything at all. So you can go for a 7 like installation, or for a chain drive, either way (but it's true that the chain drive will give more ratio choices). However the engine should be mid mounted, and it should drive the diff through a really short driveshaft, a couple of inches. Look at the Fury Menace it's done that way. As for the gear ratios, you should maybe use a Sierra box with a ration somewhere close to 4 (is there a 3.9 available?) so that the gearing is really short, that way even with the weight you have to pull, you won't burn the engine. The Freelander diff is indeed a 3.2 ratio and that is too high for a 600 kg car.

http://videos.streetfire.net/video/98e1e0d7-14a3-4bd1-9c05-98420102bbbd.htm