Conversion for the convertible: M30 it is! DONE!

[Ziggy]

I've been contemplating this for a long time, but really not got anywhere yet - a decision on what engine to go with would certainly help
I actually like how the car drives (when it drives!), & would be interested to see what it's making at the moment... But I keep seeing fast cars & wondering why I don't have one! I want to keep the E30, but the temptation is strong...

It's been off the road for a couple of weeks now, & I think I could live with not driving it for a while. Combined with looking at a certain red touring yesterday, I want some progress!
So I thought I'd start this thread, mainly to collect my thoughts & give me some incentive to get my ar$e in gear. Feel free to ignore - it ain't very exciting yet! So, the options:

M20 stroker
Pros: Just the engine to work with, no electrickery, gearbox, prop etc issues. Would get a newly built engine. I could use all my existing bolt-on bits. Actually, maybe that should be a con, as selling em could raise a fair bit of $$$...

Cons: It's still an old m20. Fairly limited as to ultimate power. If it goes pop, that's all my money down the drain.

M20 Turbo
Pros: Sky's the limit. But maybe that's a bad thing - would I ever be satisfied?! If it goes bang, it's just another m20 to drop in.

Cons: It probably will go bang. Too much of it that I wouldn't be able to do myself. Lots of initial cost!

M30
Pros: Relatively straightforward, fairly inexpensive (for replacement engines too), selling my m20 bits would go a long way!

Cons: Economy (don't care - the daily's more than cheap enough to run), Weight - too heavy in a heavy cab, or ideally suited to the lardy shell?

M52/S50 (Depending on wallet I guess! Probably wouldn't go with the m50 though as I don't think I'd be satisfied for long)
Pros: Blimmin good end result. Some people seem to manage it with very few hassles.

Cons: Complicated in most ways - some people seem to struggle for ages with em...


So there you have it. Reading through those, the M30 & M52 seem to stand out as the most likely... So which way will I go?! Decisions, decisions... I want to start collecting bits!

The big thing for me to work out:- How much will each option cost? Things like exhaust manifolds scare me most; my welding is rubbish & custom manifolds are loadsa wonga. Need to look at the options there - who could I get to help, are there options for modifying existing items & living with that for a while until I wanted to upgrade...

Hope it won't be too long before I update this / come up with a plan!
p.s: Simon13 - no, I'm not going to decide against an m20 just so you can get your grubby bits on my manifold. In fact, maybe I should hack it up to make a turbo one...

Thoughts / encouragement / offers of help are most welcome!

[Toby_Unna]

i'd say maybe m20 turbo?

reason; it looks like a nice car, a turbo conv would be fairly easy to revert to standard if need be. And a good m20 turbo even on low boost is a great reliable car, look how many miles Ant did in his SE without a problem.

a well-done m20 turbo is probably a far better idea than a hashed together m30 turbo

[Ziggy]

All valid points of course... but initial cost includes MS & lots of other people's work for making up manifolds.

I quite like the fact that with an M30 I could put it in standard fairly cheaply, then go for upgrades (chip/cam/TB/...turbo!) later on. Glad you replied to this actually mate - wanted to ask you what you had to do with the exhaust mani when you first dropped the m30 in? & (when you've got the tyres pumped up) how does it handle? Do you really notice the extra weight?

[maxfield]

Another one for M20 turbo.

[Toby_Unna]

in the end i got new wheels mate, never bothered pumping the mims up really

i'm not the person to ask about handling because my suspension isn't decent stuff, iS dampers and spax springs. some people get close to breaking down in tears about how m30s ruin the handling, but most who own 3.5 conversions don't seem too bothered by any change, if there is a significant one.

what i can say is my 335 handles a lot better than the m535 ever did

exhaust manifold? nothing doing if it's an e34 one, bolt on, attach downpipes and join to e30 exhaust system (get a flange made and welded for £30 or so, easy)

in my mind putting an m30 in as standard to begin with is obviously the only way forward! I just realise that i'm biased in terms of wanting cheap power above everything else, and i'm also well aware that a good m20 turbo is a brilliant thing

[Ziggy]

in the end i got new wheels mate, never bothered pumping the mims up really

i'm not the person to ask about handling because my suspension isn't decent stuff, iS dampers and spax springs. some people get close to breaking down in tears about how m30s ruin the handling, but most who own 3.5 conversions don't seem too bothered by any change, if there is a significant one.

what i can say is my 335 handles a lot better than the m535 ever did

exhaust manifold? nothing doing if it's an e34 one, bolt on, attach downpipes and join to e30 exhaust system (get a flange made and welded for £30 or so, easy)

in my mind putting an m30 in as standard to begin with is obviously the only way forward! I just realise that i'm biased in terms of wanting cheap power above everything else, and i'm also well aware that a good m20 turbo is a brilliant thing

that's the spirit... I heard some crazy people wash their cars too?!

I reckon you're probably right about the handling thing now I think about it - I can't think of any complaints from anyone who's actually done it...
I'm sure Hartge were relatively happy with the H35 in any case...

That's crackin news about the downpipes - I didn't expect them / the mani to clear the steering column etc. I'd just take it back to the place that made my current front section up to match the RD mani - I'd be selling that anyway....
What about sumps? & are you using the m3 prop or custom? Or the m10 gearbox?

The 3.5 seems the obvious choice at the mo tbh... Anyone feel free to change my mind though! It'd be cheap enough that I could get stuck in straight away - I wouldn't mind spending more on one of the other options, but that'd have to wait until after minor things like house deposits...

Very early draft of a shopping list (m10 option'll likely be easier than sourcing a manual 535i box & an m3 prop?):

Mounts - m30.de unless I can get some made up locally / cheaper.
Engine - E34 535i, with loom, ECU, rad, downpipes.
Gearbox - m10 E30 (& fly), uprated clutch.
'Zorst - custom straight through, to match up to 2-peice rear box.

[Ant]

M20 with snail Jon !

drop blingsta a PM maybe, there are plans afoot his end I believe....

[ric325i]

m20 turbo!

its what has to be the best option
yeah expensive to start with and if you dont know enough about turbo's it seems scary!

m30 would suit a convertable, a convertable isnt about cornering agility i guess its the same for the m30?
you could burble your way along and then open the big 3.5 when you wanted to.

[Toby_Unna]

What about sumps? & are you using the m3 prop or custom? Or the m10 gearbox?

i've got a 535i box, m535i fly, m3 prop. e34 sump is fine. i don't know about all this m10 stuff to be honest, apparently it works though.
however, there are plenty of manual 535is kicking around, and a shorten balance for about £100 is much easier than finding an m3 prop. i don't know how the m10 box/whatever clutch used would cope with the turbo that'll inevitably find its way on at a later date

[Ziggy]

Well there are plenty of kerayzee power m10 turbos out there... But I figure whichever method would work ok for now - see what turns up...

This seems all too obvious. M30 now, at little cost (not skimping, just counting selling some nice bits ), then I can start on the upgrade cycle again! Or more sensibly, not spend anything on the engine for a while, until the inevitable turbo rears it's head... Ant, how are you with m30s?!

So how are most M30s then? Do they suffer with the years, or is a good service enough to breath life back into them? Would an auto be likely to be healthier, having probably had an easier life? I know I'm looking at a big fat torque increase, but I'd still be p1ssed off to only make 190bhp. What I could do with is a drive in one to compare to my current m20...

[blingsta]

M20 turbo mate, im well ... a well mapped m20 turbo (thanks Ant) is a pleasure to drive and as you said before, "skies the limit".... wanna buy a turbo manifold?

[Ziggy]

Um... maybe! PM me some details / price if ya like

I'll have to look into the price of all the m20 turbo stuff I'd need, but my gut feeling is that it's more than I want to be spending at the moment - priorities & all that; house really must come first!

[e30_Turbo]

Turbo something, m20/m30/m42!!

I know Ants been hankering to do a M42 turbo, I've heard they can make well over 500bhp on mostly stock parts

RE MS, the cheapest way is buy the kit and make it, it's not hard, hell I did it in 8hrs, you'll learn 1000% more building it too, makes understanding it easier. Also don't discount Vems or spectre either, both as good if not better than MS. My advice is to choose which engine and them get it running on a standalone, then decide if you need more, have you driven Grandad?

[Ziggy]

I'm going to need a turbo unless I go with an S50. I guess the question is really how much I'd need to budget to get a *basic* m20 turbo build running - say m30ish figures? Fannymoulds will definately cost a lot I'm sure, but how much is the DIY MS kit? Building it doesn't scare me in the slightest

M20 turbo sounds good, but m30 turbo sounds just as good if not better, with the added bonus of being able to afford it n/a now, then sort the MS, then move on to turbo as & when the funds are available. 'iS turbo sounds interesting, but unless Ant wanted to do the work for free, I doubt it's for me! 4-pot wrongness!

I've yet to drive a turbo E30 - closest I've been was a quick blast up the road with Toby when he'd just got the blower on...

[ric325i]

it seems the turbo boys are the dedicated ones and know where to point you.

you need to ride in a m30 to feel the difference its not massivly faster than a m20 but its very different.

m30 could be a 'for now option' as i bet in a month or 2 you will be begging for more.

m20 turbo would be the ultimate e30 i have no doubts about that but a m30 turbo sounds to be a monster.

m30 for 6 months while you save for the turbo???????
you have to be committed for the conversion as it could take 10 months if you let it............not referring to me at all

but i may start mine tonight or tomorrow?

[320Touring]

I'd say m30 zig,

lots of low down grunt to get the lardy cab ass moving, and plenty of poke for cruising about.

Its a big ole lazy engine-no stress, effortless overtaking etc- just what a cab needs when the top is down and the sun is shining.

then go all TOBY on its ass, and boost its tits off

[ric325i]

I'd say m30 zig,

lots of low down grunt to get the lardy cab ass moving, and plenty of poke for cruising about.

Its a big ole lazy engine-no stress, effortless overtaking etc- just what a cab needs when the top is down and the sun is shining.

then go all TOBY on its ass, and boost its tits off

you cant complain at that.
good advice.

[Ziggy]

That does sound like the way I'm leaning...

But if anyone can convince me that m20 turbo is better than m30 turbo? I'm not in any rush really - my m20 goes pretty damn well actually; I'm just never satisfied! That's perhaps a reason not to go for the m52 - I'll get all the 'go' in one (rather more complicated) lump, & 6-months down the line I'll be wanting more... Plus the economy benefits really don't mean much to me - I have a veggie diesel for that!

I am a bit worried about how a standard m30 will compare to my m20 though - I don't want to end up with it no faster... Anyone got any thoughts on that? My 2.5 is early (high comp) in good health + ITG, BBTB, Racing Dynamics Mani, Ant 'special' chip... Guess I need to drive a m30 convertible to really get a feel for it, or at least find someone with an m30 & a g-tech! Guess my figures thread could come in useful already...

[ric325i]

dude a super healthy m20 with all that good stuff you have on it......

m30 aint going to be that much faster......at all.

i would not see the point honestly.

it will feel different and very powerful down low but if your used to top end power the m30 wont float your boat.


you may see more speed from a m30 at say 60+ but thats it.

if you chipped an m30 with a crazy cam 250bhp SHOULD be possible (de-cat naturally).

but standard m30 aint super power great for some things but on the track i would put your m20 as a winner over standard m30.

[Karan]

hmmmmm m30 is far superior..... difference in power between m20 and m30 is like night and day

[Ziggy]

Guess that's what I need to find out... track's irrelevant btw - whilst it may get a go again sometime, it's a convertible with leather & toys, not a stripped out race machine The m30 would doubtless get a little chip of joy from Sir Ant to keep it going for a while, but a cam probably wouldn't be on the cards, with a turbo planned.

Brings me back to my earlier question - what can I expect from a m30 as it pops out of an e34 / e32, & are low miles, autobox easy life etc, real big bonuses?

[ric325i]

hmmmmm m30 is far superior..... difference in power between m20 and m30 is like night and day

umm controversial.


well some people keep saying this. some dont.

its been a long time since i had my m20 and the m30 will be soon.

i would not say dont go for the m30! but you need to spend some time in one and see teh difference for yourself.

id let you have a go in mine if it was done and i was even close to you.

maybe the pod if you still deciding?

[Ziggy]

hmmmmm m30 is far superior..... difference in power between m20 and m30 is like night and day

Ah - a man who's been there! 3.5 vs GUG? Much in it?

[320Touring]

hmmmmm m30 is far superior..... difference in power between m20 and m30 is like night and day

umm controversial.


well some people keep saying this. some dont.

its been a long time since i had my m20 and the m30 will be soon.

i would not say dont go for the m30! but you need to spend some time in one and see teh difference for yourself.

id let you have a go in mine if it was done and i was even close to you.

maybe the pod if you still deciding?

I think what Karan is referring to is the spread of power in the lumps.

the m20 comes alive at about 4000rpm whereas the m30 just gets up and goes from about 1100rpm

very different engines to drive- m30 is a torque monster- always in a power band!

[ric325i]

hmmmmm m30 is far superior..... difference in power between m20 and m30 is like night and day

umm controversial.


well some people keep saying this. some dont.

its been a long time since i had my m20 and the m30 will be soon.

i would not say dont go for the m30! but you need to spend some time in one and see teh difference for yourself.

id let you have a go in mine if it was done and i was even close to you.

maybe the pod if you still deciding?

I think what Karan is referring to is the spread of power in the lumps.

the m20 comes alive at about 4000rpm whereas the m30 just gets up and goes from about 1100rpm

very different engines to drive- m30 is a torque monster- always in a power band!

not always in the power band.

when i drove the big 535i great fun but the top end felt poor, well compared to the mid power.

i guess a chip and cam could fix that

[Karan]

ziggy i just think the m30 would suit ure needs better due to the power band being so phenomenal!

and ric the e34 is a heavy old thing so you cant really properly judge the m30s peformance in that car.... in an e30 the m30 is by far the most cost effective way to get ure e30 to get to 60 in under 6secs......

In fact for a road engine for an e30 and especially a cab i dont think there is a better choice of engine. The noise with a decent exhaust also sounds sooo much nicer than a m20 as it has much more bass, which would be lovel to listen to with the roof down.

[Ziggy]

Cheers mate

The ol' m20 doesn't sound bad though; RD mani -> no centre box -> supersprint rear Would probably just go straight through to the back box again, from the E34 downpipes...

[Jon_Bmw]

Jon where are the strengthening beams on a cab. More importantly whats the weight distribution like front to back. I'd just be worried that you might be making an e30 more understeerey. As a point of interest theos when watching him at coombe didn't seem to be understeering in fact he spun it under braking iirc. BUT and its a big BUT his is totally stripped out. I know you enjoy driving it and think that perhaps taking out a 2 valve per cylinder engine and putting in another might piss you off.

If it was a stripped out cheap racer, m30 would be an ideal candidate. After all you pop the engine and its only £150 to get another. But yours isn't.

I would recommend a 2.8, 220bhp out of the box with an inlet manifold change. You get a tubular exhaust(you are a sucker for these ) 4 valves per cylinder. IF you got bored, you are all equiped for an s50. I think the 2.8 has EWS and you'd need to move the brake master cylinder over so it would almost be ready to drop in an s50 after a couple of years.

Plus you can look at jimbobs if he ever gets it sorted and get a first hand view of it.

[320Touring]

BOO HISS! down with multi valve wrongness!

2 valves per cyl for the win

[DRIFTBOY]

I think Theo's spin at Castle Coombe was partly down to having standard front brakes and bigger Z1 rear discs and M3 calipers.

His standard highish milage M30 made 199bhp on the rollers there too, with a blowing exhaust and something else, that I can't remember, which could also have dropped a bit of power.

You know big six rightness makes sense!

[Jon_Bmw]

You lot are living in the past

Martin point taken, it probably was that. Jon say yours has got 180bhp, are you going to notice an extra 20? Or will 40 put a bigger smile on your face. If you got an perfect m30 then it should have 230bhp of whatever, but these are oldish engines that have been dragging round heavy old barges for a while, so its unlikely you'll find a good one for the "right" price. Just my opinion.

Looking at dameons 330 would make anyone instantly want to do that conversion, I just think that the 2.8 is the right stepping stone for it.

[Theo]

Haha, my spin was so lame - mainly caused by a lazy downshift without heel/toeing!! My old starship mileage engine did 199bhp & 225 ft/lbs. The extra 60ft/lbs (compared to a 325i) is very noticeable, i'm really not sure what turd Ric has experience of but it doesnt sound right. I've hopefully got a few more ponies now after sorting the blowing exhaust, fitting a better dizzy cap & rotor, new air filter and cold air feed and also new spark plugs. You are welcome to come for a spin in the car at Santa Pod if you come up.

I'd say M30 is ideal for your needs, the linear power delivery is great fun. I don't think you need to worry about understeer on a cab, unless you drive round close to the limit of grip on open roads? That said, Jons post above is well made, and M52 with the right bits would be nice, but value for money - M30 wins it IMO.

No more cambelt and cast crank tat like the old M20 with the M30 btw.

[Jon_Bmw]

Haha, my spin was so lame - mainly caused by a lazy downshift without heel/toeing!! My old starship mileage engine did 199bhp & 225 ft/lbs. The extra 60ft/lbs (compared to a 325i) is very noticeable, i'm really not sure what turd Ric has experience of but it doesnt sound right. I've hopefully got a few more ponies now after sorting the blowing exhaust, fitting a better dizzy cap & rotor, new air filter and cold air feed and also new spark plugs. You are welcome to come for a spin in the car at Santa Pod if you come up.

I'd say M30 is ideal for your needs, the linear power delivery is great fun. I don't think you need to worry about understeer on a cab, unless you drive round close to the limit of grip on open roads? That said, Jons post above is well made, and M52 with the right bits would be nice, but value for money - M30 wins it IMO.

No more cambelt and cast crank tat like the old M20 with the M30 btw.

Equally well made points sir I think i was getting to involved into the possible handle characteristic changes and old technology. Its a 1990? cab after all and meant for crusing with blats on the motorway etc. Not farting about on track. Bang for buck, m30 is clearly the best choice. Just part of me would want a newer engine.

[Speedtouch]

No more cambelt and cast crank tat like the old M20 with the M30 btw.

What crank does it have, out of interest?
Cheers,

[Theo]

It has a nice forged steel crank, which is much stronger (and much heavier!) than a cast crank as used in the M20. Alpina used a forged steel crank for their 2.7's and I imagine Hartge & others did the same.

If you did choose to turbo it, and it is a huge tempation, then the engine will be more than happy to run big power, as Toby's hero chariot shows.