Board logo

gsxr 1000 04 into mx5 1990
phil clegg - 19/1/12 at 11:49 PM

Starting this new project,i have an mx5 and gsxr. with all bike parts.Can anybody tell me if the sump will baffle ok?Where to have it done ?Will be using bike clock,is there a way of using the gsx speedo .Can i buy a reverse sprocket and make a suitable starter fit as £350 seems a lot for a kit.Any sugestions or tips for anthing else i will need,thanks Phil 0795617548

orton1966 - 20/1/12 at 06:30 AM

Not wanting to be too critical but one thing to consider is weight. Whilst not a heavy car (about 940kg) the mx5 is still over 300+kg heavier than most BEC 7’s and 400kg heavier then the lightest of them.

Yes, putting the bike engine in will save something, maybe 30-40kg but the weight penalty will still be high. It’s not the power that's deficient on a bike engine but the torque and that’s why they work best in light vehicles.

Like I say, not saying don’t do it, it’ll still be fairly quick. Just consider weight in every decision you make i.e save as much as you can, wherever you can.

Or stick a turbo/supercharger on it!

[Edited on 20/1/12 by orton1966]

Dangle_kt - 20/1/12 at 10:39 AM

interesting idea - personally I agree with whats been said though.

You really notice when you have a passenger (500kg car, plus me 80-90kg, plus passenger 70-100kgs) - that extra 70-100kgs really blunts the performance.

Your car will be +400kgs without a passenger, so I imagine it will have an even bigger effect.

TimC - 20/1/12 at 12:10 PM

I did a couple of trackdays a few years back with a beautifully engineered 'lightweight' 205 with a Fireblade engine. Dog-slow I'm afraid - he put a Zetec in it eventually I think.

cosmick - 20/1/12 at 02:28 PM

To use the speedo, all you need to do is use the standard Suzuki speedo pick up (usually mounted on the sprocket cover) and mount it by the front propshaft adapter. fit it so that it uses the 4 bolts as relucters and the signal will drive the speedo. if the speedo needs adjusting, buy a Speedo Healer from Heal Tec and the job is done.

[Edited on 20/1/12 by cosmick]

Rocket_Rabbit - 20/1/12 at 06:18 PM

quote:
Originally posted by orton1966
Not wanting to be too critical but one thing to consider is weight. Whilst not a heavy car (about 940kg) the mx5 is still over 300+kg heavier than most BEC 7’s and 400kg heavier then the lightest of them.

Yes, putting the bike engine in will save something, maybe 30-40kg but the weight penalty will still be high. It’s not the power that's deficient on a bike engine but the torque and that’s why they work best in light vehicles.

[Edited on 20/1/12 by orton1966]

Total and utter rubbish.

Power is the only thing that matters, torque is altered by gear ratios.

Yes, you feel the passenger in a BEC because you have just added 15% extra weight to your car.

Are you planning to use the Bike gearbox?

phil clegg - 20/1/12 at 09:12 PM

yes direct prop to rear diff like in a seven,i have spoke to ab performance who were very helpfull ,need billet sump ,drive flange and one off prop,costs about a £1000 also may need one off exhaust,was hoping to use at least the downpipes,not sure if these will interfere with modded sump,ithanks for the replies,phil

Steve Hignett - 20/1/12 at 09:28 PM

quote:
Originally posted by phil clegg
also may need one off exhaust,was hoping to use at least the downpipes,not sure if these will interfere with modded sump,ithanks for the replies,phil


You can use the downpipes and most of the exhaust to be honest, butonly as donor curves and straights to make up your own exhaust.

Most superbike exhausts follow the same path. Out of the front og the head, down the block, under the sump and then obv past your leg to a can at the back of the bike.

So in the MX5, the OE exhaust routing would end up going somewhere near/through the OSF strut/coilover.
Easiest thing to do, would be as I've said above, cut-n-shut the pipes into bends and straights. Get some more straight pipe, the same Dims and make your own (or get someone to make it for you).

You can do some work yourself if you have a welder, or even some decent tape.
Get it cut pretty much where you want it, then you (or a welder mate) tack it into position, then take it to a local Tig welder or someone on here (Welderman - Joe) is an exellent welder who charges other LCB'ers as little as he can afford to get away with at his work, to finish the welding...

Robert's your fathers etc etc

I won't bother commenting on the feasability an performance of the project on the whole. Some things just need to be "gotten out of our systems"!!!

ATB

Steve

scootz - 20/1/12 at 09:30 PM

Is the performance important to you Phil, or is it just an engineering exercise for the sheer hell of it that you're embarking on?

wylliezx9r - 20/1/12 at 09:33 PM

I've been in a mini with an r1 engine up front. Must be quite heavy because it has full leather interior, full roll cage, sound system etc. It was very quick torque steering everywhere in the first 2 gears. I can't see you having any weight issues with the mx5. Ditch the heaters sound proofing, spare wheel etc and you'll be onto a winner I think.

phil clegg - 20/1/12 at 10:17 PM

i would like to do it for the fun of it,but i will not do it if it looks like a money pit,i am sharing costs with a friend who has the engine,its an 05 1000 gsxr,allready bought an mx5 but as i have added up the cost and can not give the 1.6 mazda engine away,my bottle is going a bit at the moment,the more i check the dearer it gets...

Stott - 20/1/12 at 10:33 PM

quote:
Originally posted by TimC
I did a couple of trackdays a few years back with a beautifully engineered 'lightweight' 205 with a Fireblade engine. Dog-slow I'm afraid - he put a Zetec in it eventually I think.



I don't know if you're on about robins pug or not, White 205 with a blade lump, subframes f+r, 700kg wet. It was far from slow, would show a clean pair of heels to most things on track due to the gearchange, braking and handling.

He fitted a zetec sigma in the end due to the msa stopping giving logbooks to becs but despite making more power and torque it killed the car really, lost it's pace big time. He then sold it and apparently it's cleaning up in rally's.

Prior to this he'd made and log booked about 4 busa 205s and they are mega competitive fair play. It can be done, it just takes a keen eye to make it light enough.

There's videos showing the Bec pug somewhere on YouTube leaving a lot of p'd off people behind

Atb
Stott

orton1966 - 21/1/12 at 07:18 AM

quote:
Originally posted by Rocket_Rabbit
quote:
Originally posted by orton1966
Not wanting to be too critical but one thing to consider is weight. Whilst not a heavy car (about 940kg) the mx5 is still over 300+kg heavier than most BEC 7’s and 400kg heavier then the lightest of them.

Yes, putting the bike engine in will save something, maybe 30-40kg but the weight penalty will still be high. It’s not the power that's deficient on a bike engine but the torque and that’s why they work best in light vehicles.

[Edited on 20/1/12 by orton1966]

Total and utter rubbish.

Power is the only thing that matters, torque is altered by gear ratios.

Yes, you feel the passenger in a BEC because you have just added 15% extra weight to your car.

Are you planning to use the Bike gearbox?


Power is not everything, yes at the very ultimate limit it is might be but all other things being equal i.e. max power, weight, gearbox etc. even on track the car with more torque will be quicker.

The reason - because there will always be one corner one acceleration zone when you’re not quite on cam, here the equally powerful but more torquey car will have an advantage. This is why some of today turbo diesels are so quick point to point.

Anyway I didn’t say don’t do it, I said loose as much weight as you can, 700-750kg would be a nice target!

StevieB - 9/4/12 at 12:30 PM

Are there any updates on this project yet?

I was doing a search on the subject as an idea for my next project and would be keen to see how others are getting on

Cheers

Steve