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BMW 120 thoughts
crabz013 - 25/8/20 at 07:27 PM

Hi. New here and wanted some thoughts on a possible build. I have a BMW 1 series which has a broken engine and a 1000 Yamaha which has been for a slide along the tarmac. Engine is good and runs but will need re-wiring.
How easy would it be to put together into a locost and which chassis would be a better option? Or possibly even a pre assembled one?
I am a HGV mechanic by trade so the wiring, welding and fabrication shouldn’t pose much of a problem but I am a little unsure, maybe someone may have done it before?
Thinking De Dion axle or possibly even IRS?
Longer term if it works out well then will possibly turbocharge and convert to a Megasquirt Ecu or similar!
Thanks in advance and don’t be shy, I would like real opinions, I know it is a little different!
Karl

rf900rush - 25/8/20 at 07:45 PM

Sounds like you are half way there.

A few years back I built a Dax Rush and went the bike engine route.
I think my build was no more difficult than a car engined version.

At the build stage I used a Suzuki RF900 and ford Sierra as a a donar.

I believe a lot use BMW now, as it one of the few rear wheel drive cars left that has been used in seven's.

Later on I upgraded to Megasquirt (RF900 runs carbs) using GSXR600 K1/K2 injection bodies.

Go for it

crabz013 - 25/8/20 at 07:57 PM

Thanks rf900rush. This is a fzr1000 so still on carbs as well. I may keep it with the carbs but unsure at the moment, if not then I will probably go with the GSXR600 / 750 throttle bodies. Seems they are a popular conversion for quite a few now. How did you find them, were they noticeably better and smoother? And did you find tuning the ecm easy? I haven’t yet touched anything like the Megasquirt so would be a challenge!

perksy - 25/8/20 at 08:35 PM

Welcome


What do you plan to use the car for?

Road & Track days or just Track days?

Have you been in bec before ?

crabz013 - 25/8/20 at 09:29 PM

quote:
Originally posted by perksy
Welcome


What do you plan to use the car for?

Road & Track days or just Track days?

Have you been in bec before ?


Thank you perksy

Mainly for road use with the the occasional track day.
I suspect the wife would want to drive it as well, she is a bit of a petrolhead as well, although we haven’t discussed yet, so would like it to be quite easy and reliable ish.
I wouldn’t have thought there was too much difference between De Dion and IRS when there is next to no weight in it but welcome to be corrected.

ettore bugatti - 26/8/20 at 11:03 AM

Caterham uses the 1 series diff (168) in their cars, but as far as I know nobody have used the 1 series before for the brakes, hubs, uprights and driveshafts.

Is it a diesel? diff ratio might be better for a bike engine.

perksy - 26/8/20 at 07:29 PM

Bec great for track days but not sure I'd fancy one for road use, too many rev's and clunky drive train for the road, there's also a reverse to sort out
I'm sure many would disagree but just my 2p


I've not seen a 1 series engine in 7 before and I'd be curious of the dimensions and if/how it'll fit
Would you want to try and retain the BMW gearbox ? If so how big is it and also the bellhousing? It also use a dual mass flywheel doesn't it?


Quite a bit of planning needed on this one, but it's always good to see something different

Simon - 28/8/20 at 11:48 PM

Don't worry about being different or we'd all be driving the same dull eurobox.

Anyway, having built from scratch (and currently building a mid-engined V8 Beetle), if I was doing another 7 esque car, I'd "cheat" and buy a kit.

As you have BMW bits, it might be worth giving DMO, formerly GKD (https://dmosportscars.com) a call as they use BMW bits though for IVA may be worth getting a replacement engine for the 1 series, if you're worried about Q plates, emissions and stuff

I always thought the 1 series would be the ideal size for a 7 rep but haven't looked underneath ....

Keep us updated with whatever you decide

crabz013 - 29/8/20 at 06:10 PM

quote:
Originally posted by ettore bugatti
Caterham uses the 1 series diff (168) in their cars, but as far as I know nobody have used the 1 series before for the brakes, hubs, uprights and driveshafts.

Is it a diesel? diff ratio might be better for a bike engine.


Thanks ettore Bugatti, yes it is a diesel but have not looked at the ratio yet so will have to check that one

crabz013 - 29/8/20 at 06:21 PM

quote:
Originally posted by perksy
Bec great for track days but not sure I'd fancy one for road use, too many rev's and clunky drive train for the road, there's also a reverse to sort out
I'm sure many would disagree but just my 2p


I've not seen a 1 series engine in 7 before and I'd be curious of the dimensions and if/how it'll fit
Would you want to try and retain the BMW gearbox ? If so how big is it and also the bellhousing? It also use a dual mass flywheel doesn't it?


Quite a bit of planning needed on this one, but it's always good to see something different


Hi perksy. I do wonder with the bike engine and box if it would be all revs but it is a sequential gearbox and could easily make a quick shifter or adapt something. Even a paddle shift perhaps. Reverse gear is another issue but there are ways around it.

I have had a closer look around the BMW as it would only be going for scrap otherwise and I think it is possible but there are a few other problems to get around. I think the biggest would be converting the rear suspension to Independent rather than the De Dion approach, I know it is less common but will certainly be different.

I did look at replacing the broken timing chain or engine and maybe tuning it, even though it is a diesel, just to be different, but it is a heavy engine and the gearbox isn’t exactly light either. I will keep to one side for the moment and see, can always change my mind!

Might start the build and get it up and running, then change it to the BMW diesel later down the line.

crabz013 - 29/8/20 at 06:39 PM

quote:
Originally posted by Simon
Don't worry about being different or we'd all be driving the same dull eurobox.

Anyway, having built from scratch (and currently building a mid-engined V8 Beetle), if I was doing another 7 esque car, I'd "cheat" and buy a kit.

As you have BMW bits, it might be worth giving DMO, formerly GKD (https://dmosportscars.com) a call as they use BMW bits though for IVA may be worth getting a replacement engine for the 1 series, if you're worried about Q plates, emissions and stuff

I always thought the 1 series would be the ideal size for a 7 rep but haven't looked underneath ....

Keep us updated with whatever you decide


Hi Simon, that’s probably the whole point of this, something different.

I have looked and for the price and time taken the pre assembled chassis has got to be the better way, I know I will have to cut it around a little for the BMW rear suspension and will have to fabricate some wishbones, etc but at least I have a reasonable starting point then. Bike engine to start with as I have one and it’s ready but beginning to like the sound of a 2ltr tuned diesel turbo engine sometime further down the road.
I had looked at the DMO cars but if I remember rightly, more of a body kit and although it is different, it’s not that different. Still very nice just not quite what I was looking for.
V8 into a beetle, mid engined just behind your ears, that’s different. Would love to see some pics of that sometime, what is the engine? Hemi, Chevy, Ford? Some of these newer fuel injected ones are becoming increasingly available nowadays but not so rough around the edges!

Karl

Simon - 30/8/20 at 09:15 PM

Hi Karl,

The Beetle is mostly keeping within VAG- engine is from Audi A6 v8 4.2 with 335bhp, gearbox from Porsche Boxster, rear suspension is also from the Audi but narrowed. Front suspension is Mazda RX8 suspension.

I'm scratch building the chassis.

I've started a vlog which I need to update but will put up a link later 😊

crabz013 - 6/9/20 at 02:57 PM

quote:
Originally posted by Simon
Hi Karl,

The Beetle is mostly keeping within VAG- engine is from Audi A6 v8 4.2 with 335bhp, gearbox from Porsche Boxster, rear suspension is also from the Audi but narrowed. Front suspension is Mazda RX8 suspension.

I'm scratch building the chassis.

I've started a vlog which I need to update but will put up a link later 😊




That sounds like a monster, Can’t wait to see this one finished.
These newer engines can be a real wolf in sheep’s clothing when pulled up to a boy racer at the traffic lights!