318is v m3

[stof]

I went for a ride in one of the kumho cup BMW e30's (M3) not so long ago and even from being a passenger you can kind of tell that its a pretty fun and decent handling car.

Now i have a 318is which im preparing for some single venue rallying, just tarmac stuff for now, and from researching it seems that alot of the rally boys who run e30's have the M3.

I know alot of people on here race non-m3's but its just out of curiosity but is there any difference between a standard m3 and 318is chassis, in the respect of any major differences eg width / wheelbase etc. or is the m3 just better set up for performance etc.

What i'm asking really is would or can a well prepared 318 handle as well as an equally well prepared m3?

Cheers guys.

[Jhonno]

Yes it can, it'll never quite be an M3 but near as damn it for a lot less

You would need the arb pickups welded to the strut like the M3, some decent suspension and wheels, uprated brakes

[harry_p]

Yep, the e30 basics are very similar between standard car and m3, no reason why a standard 318 can't be made to handle as well or better than a standard m3. A lot of people use m3s as long as they fit in a category due to their engine size because you start with 60 bhp more, and tuning parts are tried and tested and fairly easy to find.

[AlpineAde]

There's no reason why a 318i could not be made to handle very well indeed.

[shorty73]

Talk to the PBMW boys. A lot of there cars handle extremely well and they are often heard complaining that the "quicker" cars are holding them up through the corners.

A 318is shouldn't be too far off the mark of a 325is. Bit of cash in the right place and that should be up there. I scalped an e36 M3 at Spa so it's definitely possible.

[UweM3]

There's no reason why a 318i could not be made to handle very well indeed.

second that!

[DawieM3]

AlpineAde wrote:
There's no reason why a 318i could not be made to handle very well indeed.


second that!

I agree that you can improve the 318i and get it to handle well, but lets be serious here, its never going to handle to an equally upgraded m3. If it did then everyone would simply fit S14`s into a 318i as they are cheaper and easier to find. Just my 2p worth.

[GrindCulture]

AlpineAde wrote:
There's no reason why a 318i could not be made to handle very well indeed.


second that!

I agree that you can improve the 318i and get it to handle well, but lets be serious here, its never going to handle to an equally upgraded m3. If it did then everyone would simply fit S14`s into a 318i as they are cheaper and easier to find. Just my 2p worth.

I feel you've missed the point here. An iS can be made to handle very well for a lot less cash than a sorted M3. Sure a sorted M3 will be better, but then spend more money and you can get something even better again.

[N00b]

AlpineAde wrote:
There's no reason why a 318i could not be made to handle very well indeed.


second that!

I agree that you can improve the 318i and get it to handle well, but lets be serious here, its never going to handle to an equally upgraded m3. If it did then everyone would simply fit S14`s into a 318i as they are cheaper and easier to find. Just my 2p worth.

Surely, unless the M3's bodyshell is different (and other ordinary shells cannot be modifed in the same way) then all M3 parts can be fitted to any lesser model from the e30 range giving exactly the same results.

The M cars are very good, but they're not made out of pixie dust and built by elves.

[Jhonno]

The M3 shell is very different..

[N00b]

The M3 shell is very different..

I'd imagine there is a fair bit of extra strengthening, but are there areas that cannot be duplicated on a regular shell and if so why not?

[Jhonno]

Things like the rear screen angle, arches

End of the day anything on an M3 shell can be copied with enough time and money

[DawieM3]

I feel you've missed the point here. An iS can be made to handle very well for a lot less cash than a sorted M3. Sure a sorted M3 will be better, but then spend more money and you can get something even better again.

What i'm asking really is would or can a well prepared 318 handle as well as an equally well prepared m3?

Think someone else should read the last sentence of the first post again.


Regards,

Dave

[Dave_M3]

Don't think there is any extra strenghtening, the differences are the arches obviously to allow the wider track (which is mostly due to the wheels more than the suspension really) and the m3 is significantly more aerodynamic because of the totally different rear end.


But... I would believe a 318iS could be made to handle better than an M3 if the same money and qaulity of parts was spent on both.

You could fit a 5 stud conversion with E36 M3 and Z3 parts and straight away you could have coilovers and brakes for a price that would be hard to match on getting parts for an M3.

If you went to buy an M3 costing 10K and put another 10K into the engine to rebuild it and bring it up to 270bhp etc, you'd have a 318iS for under 1K and then rebuild the engine to S42 standard and would blow an S14 away on a track (10K mile rebuilds aside, lol)


Still, I suppose a M3 will always look and feel alot cooler on the track

[Jhonno]

Using e36 parts will compromise handling, but offer you options with brakes..

[Dave_M3]

Why? If springs suited to an E30 and geometry set up right with adjustable camber and castor etc...

Also, it's hard to find a Z3 rack for an M3 too

[Jhonno]

You can't get ideal geometry.. You can get close, but not perfect

[Dave_M3]

Hmmm, suppose so...

Still M42s are lighter than S14s

[UweM3]

with the recent explosion of M3 prices/parts prices you need a lot of money for a decent prepared M3 IMHO.
The 318iS lack of aerodynamic can be sorted with an S50....(or 540 V8, or turbo, or 1.8 VAG turbo).

I had an eye opener on the Ring last year. Standard looking white E30, stripped and cage. Even had 4 lugs still on.
Didn't even stand a chance when he put his foot down. S50B32 under the bonnet (with CSL style carbon box) and H&R Ring spec suspension. It can be done.

[stof]

Thanks for all the info guys, some interesting posts there.

I understand that a 318 will never be an m3, but as long as underneath its a similar thing then im pretty happy
I was just hoping that it wasn't a case of 'M3 is completely different, and you have no chance with a 318'.

One thing which does interest me is the '5 stud conversion with E36 M3 and Z3 parts and straight away you could have coilovers and brakes for a price that would be hard to match on getting parts for an M3'. I'll have a gander on the forum about this afer writing this, but around how much would this conversion cost, and is it a matter of swap the components over (not brakes etc.) or is some sort of fabrication required? As it would give me more options with brakes and suspension like you said!

The car is having a roll cage fit at the moment, which will be picking up on the front and rear shocks so that sould add some rigidity, then when i get it back i'll go to the diff myself. Just want to get safety stuff done properly!

The plan with the engine is to use a N/A 13b rotary from a FC RX7 as they are tiny things and can be mounted really low and far back in the engine bay and UK MSA only class it as a 1.3l capacity engine for Stage Rallying and 1.95l for Sprints and Hill Climbing, so that will put me in a lower class for the rallying. The place i'm getting the cage done run a rotary escort mk2 and that thing flys, plus the engine apparently weighs just over 95kg, which inspired me!

Anyway thanks for the help once again guys!

[Jhonno]

Wow, love your engine plan, for the noise if nothing else..

The E36 setup done properly isn't cheap, is more hassle, but more readily available.. You have to use e36 offset wheels etc after.

The front HAVE to be made up of the following components to get decent geometry..

E30 M3 TCA bushes.
E36 M3 Evo TCA's.
E36 M3 Evo Hubs/brakes.
E36 Struts (make it M3 for the ARB droplink tabs that will improve handling)
E30 Offset/sdjustable topmounts and spring plates.
E30 springs.

[Dave_M3]

Well, even the RX-7 engine alone will give you great handling before you even start upgrading stuff. It could even be too light to make 4 pot E30 springs work properly, lol.

The 5 stud conversion is all bolt on but as Jhonno said, it isn't very cheap because of trying to find the M3 Evo bits then a set of coilovers with everything adjustable but it will still end up abit cheaper than finding E30 M3 suspension bits to bolt on.

Since you have a very light engine, even a set of E30 fitment 4 pots and good discs and pads would nearly do you for brakes but availibility of coilovers are harder to come by then obviously...

[juniorGT]

1.8 VAG turbo).

hmmmm iv had many thoughts about this. as the Passat 1.8T is longlituidly mounted. and i could get one very cheap !

that would an immense conversion as the 1.8T is a modern light weight engine (no increase in understeer) plus with a KO4 running Emarald you will be seeing 250bhp & 300fpt very easily... plus with my fully stripped interior, power to weight would be crazy, would need a long ratio diff though (thinking Z3?) lol

just out of interest anyone done this?

[Dave_M3]

[quote="juniorGT"]
just out of interest anyone done this?[/qoute]

No... they were too afraid of being hung drawn and quatered by the purists

[shorty73]

Rally boys don't care for purists as long as it works!

[Jhonno]

It's only an iS.. Do it!

[Dave_M3]

Yeah, the sale of the M42 should nearly cover the cost of some old VAG eurobox anyway

[juniorGT]

It's only an iS.. Do it!

oi ! i might just lol

[Stevin]

with the recent explosion of M3 prices/parts prices you need a lot of money for a decent prepared M3 IMHO.
The 318iS lack of aerodynamic can be sorted with an S50....(or 540 V8, or turbo, or 1.8 VAG turbo).

I had an eye opener on the Ring last year. Standard looking white E30, stripped and cage. Even had 4 lugs still on.
Didn't even stand a chance when he put his foot down. S50B32 under the bonnet (with CSL style carbon box) and H&R Ring spec suspension. It can be done.

I'm loving this post!

because, u take said engine, fender flares, big brakes, gutted and aero... then u have my race car, and yup it it facks off!

As they say u can't turn a pig into a cheetah, but u sure as heck can make one fast pig :;)

[JungleGus]

iS Slow? M3 Fast?

for rally, i would get a 6 pot - the handling is not as bad as everyone makes out, they can handle very well. plus, you get torque! good for rally corners!

[bss325i]

AlpineAde wrote:
There's no reason why a 318i could not be made to handle very well indeed.


second that!

I agree that you can improve the 318i and get it to handle well, but lets be serious here, its never going to handle to an equally upgraded m3. If it did then everyone would simply fit S14`s into a 318i as they are cheaper and easier to find. Just my 2p worth.

Why wont it handle as well? The floor pans, chassis rails, bulkhead, inner arches, inner wings, strut towers etc are the same between M3 shells and normal 2dr shells, so if they were equally upgraded as you say, there would be no difference.

The improvements of an M3 shell over a standard shell were to accomodate wider wheels and improve aerodynamics.

[bruvs1]

I've used both 4 lug and 5 lug for rallying, imo theres little point changing the E30 geometry to E36 when rally bilsteins are readily available for 4 lug 51mm struts and for the back. The 4 lug front suspension does have a smaller wheel bearing but its hardly under designed and the blue book for rallying limits the wheel width for engine size too. Brakes can be easily uprated too

[stof]

I've used both 4 lug and 5 lug for rallying, imo theres little point changing the E30 geometry to E36 when rally bilsteins are readily available for 4 lug 51mm struts and for the back. The 4 lug front suspension does have a smaller wheel bearing but its hardly under designed and the blue book for rallying limits the wheel width for engine size too. Brakes can be easily uprated too

Fair enough. I have kinda given up on the idea of converting to 5 lug due to cost really.

Need to start looking into some suspension soon, so any idea on whats best to go for? What are the Bilsteins, i did have a quick look a while ago on their website but didnt find much.

[bss325i]

I've used both 4 lug and 5 lug for rallying, imo theres little point changing the E30 geometry to E36 when rally bilsteins are readily available for 4 lug 51mm struts and for the back. The 4 lug front suspension does have a smaller wheel bearing but its hardly under designed and the blue book for rallying limits the wheel width for engine size too. Brakes can be easily uprated too

Fair enough. I have kinda given up on the idea of converting to 5 lug due to cost really.

Need to start looking into some suspension soon, so any idea on whats best to go for? What are the Bilsteins, i did have a quick look a while ago on their website but didnt find much.

The only advantages of five stud over four stud are the bigger front wheel bearing, repositioned front ARB link mount (which can be added to four stud struts) and a bigger choice of wheel.

Thats it.

[mt1104]

I would double check the classing of rotary engines, as some events are limited by cylinders and under bluebook regs a single rotary counts as 3 cylinders. Also some count the capacity of one rotor as 3 times its capacity (effectively making a 1.3 RX7 engine a 3.9L engine)