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BMW 325i Sport
senojnitram - 15/3/05 at 07:33 AM

Hi all, it's my first post here, so be gentle with me!
I have been planning to build a locost for some time now, just over a year in fact. I thought I'd wait to see if the enthusiasm would wear off, it hasn't!
So now I'm getting to the planning stage (throwing ideas round the pub!)
I want to use a 89/90/91 ish BMW 325i Sport as the donor. Has this been done before?
If it is a total no, no. Can you suggest a car to use, something with plenty of grunt!! Minimum 2 litres.
Look forward to your replies.

Martin


JoelP - 15/3/05 at 07:40 AM

deviants are punished by slow builds, but then there is the satisfaction of making something different. Somebody has undoubtedly used this donor, but i havent heard about it.

The downside would be weight, maybe size (is it a straight 6? might be too long for a normal chassis) and the fact that no one could help with the specific issues you would face (eg engine wiring etc).

plus side is obviously the uniqueness etc.

think long and hard about engine choice. What if using an unusual donor adds so much time to the build that you run out of motivation and give up!


senojnitram - 15/3/05 at 09:49 AM

hmm, thought that might be the case...low mileage sierra anyone?


ned - 15/3/05 at 09:51 AM

hugh patterson and metal hippy have been penning designs for a bmw based locost, derived from a +4 with extra length iirc, try a search on their usernames and it may throw up some useful previous discussion..

Ned.


Volvorsport - 15/3/05 at 10:44 AM

nice gearboxes , especially a sport gearbox , close ratios etc - possibility of fitting an M3 engine . sounds good on paper .

im going volvo turbo - lots of torque in boost - but im also uprating internals - and shooting at two bar boost . should be good for 450 - 500 hp . If i build the head right .


senojnitram - 15/3/05 at 10:56 AM

if using the volvo, what front end components do you use?
standard sierra stuff with uprated brakes.
That is my main stumbling block.
If i use the bimmer, should I still use the sierra for steering etc???

[Edited on 15/3/05 by senojnitram]


mookaloid - 15/3/05 at 11:08 AM

I think that the time is coming when we will need to look very closely at cars like BMW's as donors. The supply of Sierras is not infinite and unless we all go middy in the future, the BMW is an obvious candidate.

So Martin why not give it a go? It will be a challenge but potentially a superb car


clbarclay - 15/3/05 at 11:45 AM

BMW's as far is i know have McPherson struts like ford escorts that can not easily be turned into wishbone suspension unlike the sierra struts which unbolt and only need an insert adding.

Make sure you know what you want from a build first, I'm leaving interseting more engines etc. for my second car and getting to grips with a book locost to start with.

As for a straight six, why not +642, that would keep the track width to wheel base ratio about the same. and 2 inches extra in engine bay over a +442 chassis.


Tigers - 15/3/05 at 12:01 PM

Hi!
I'm also building BMW 325i based locost. And have spent A LOT of time learning, planing, drawing etc.
Currently I have almost finished the chasis and working on suspension.
So the chasis is +442. But now I'd rather go for wider front and also maybe slightly higher,as the engine is quite tall with it's intake over cam cover (I'm planning of re-designing intake mainfild in distant future). Now my wishbones are so long that with locost shocks I have to make special bar to mount them to chasis (I don't want to incline them too much or move inwards). Long wishbones are not bad as this gives less camber change, but then the problem is you need short rack. Currently using original rack, but might be problems with bump steer (will see when everything's put together). I'm using also original McPearson strus, cut quite low and welded insert to accept rose joint at top.
Rear suspension - again original bearing housing cut off and machined, then welded to plate and custome made upright (not finished yet). Well, if I had to start over then I would use the engine, of course, but use dedion at rear and front from Siera or Cortina. That would make life a lot easier and build a lot quicker. But that's not fun, right?


clbarclay - 15/3/05 at 02:14 PM

Tigers

what is the standard rear suspension on a 3 series then?


Tigers - 16/3/05 at 08:59 AM

Semi-trailing arm, just like Siera. Not very Locost friendly.

[Edited on 16/3/05 by Tigers]


JamJah - 22/3/05 at 05:03 PM

Wasnt there going to be a third ed of the bible using a 3 serise as a donor? Or was that just a rumour?


ned - 22/3/05 at 05:24 PM

there are so many rumours about a 3rd edition, there was a whole thread (or two) on it a while back. It's meant to have sections on IRS, bike engines, dedions, GTS shocks, solve 3rd world famine and everything..

Ned.


itguy - 26/3/05 at 07:32 PM

My father-in-law is using a 325i E30 ('89) as a doner for a marlin sportster, so I know all about the engine, stripping it down and what can/can't be used etc.

The engine electrics are a doddle, its a self contained engine loom including ECU, so just a few wires to splice into the loom you will be using to build your locost with (PWS etc). BMW loom colours are DIN standard, not Lucas so some diagrams of the system and a conversion chart is useful.

The engine is a bit tall and long, there is no way I could get it in my westfield (even if it were a wide).

Other things that may be of use are that the 325i came with an open diff (LSD as a factory option) but all 325i SPORT models came with a LSD as standard.

Early 325i's had a different version of the Bosch fuel injection to the late ones, but it doesn't really change anything for your build.

(personally the engine is just gagging to have the standard injection taken off and a set of triple weber 45's bolted on)

In standard tune from the factory the engine is booked at 170bhp, although with a nice free flowing exhaust and air filter system I know of one thats around the 190bhp mark without any other mods.

Hope that helps,

Will.


pgpsmith - 19/4/05 at 05:16 PM

Bimmers are certainly more common here than Sierras (Merkur XR4ti.) Do any of you BMW lads have a weight on an E30 diff? W or w/o halfshafts? Anything to watch out for technically?

My other contender is a 2nd gen RX7 diff. (51% settled on DeDion.)

Regards,
Mr. Pete


Tigers - 21/4/05 at 05:13 PM

BMW e30 rear diff (non-LSD) 29KG with oil.
Each driveshaft 7 Kg.

Cheers,
Janis


wilkingj - 21/4/05 at 08:04 PM

The Luego Viento Chassis is sized and spec'd for BMW engines. Its definately big enough Engine bay wise.

Click on the Luego Icon at top of the page and follow the links to Cars and viento.


pgpsmith - 23/4/05 at 03:51 AM

Thanks, Janis! Much appreciated.

Mr. Pete


chet0213 - 2/5/05 at 09:57 PM

hello everyone. Im a newbie , names chet. currently building a book built car and we are using a 3.3litre out of a old bmw 5 series. we are going to use the suspention components of a 325is thought. we have found by removing the fan and the intake manifold the engine will fit. we are in the process of making a custom intake out of alumiunum. will post pics when finished.