E34 m20 upgrades.

[offthewall]

for all the m20 guys out there..

since most of the stuff out there will not fit our cars..
what have you done to your E34 m20 motor?

suspension / engine / etc . . .

[323I Junkie]

Most of the stuff wont fit our cars?
Theres a million M20 mods, from turbos and stroker kits to high perfromance heads and aftermarket chips, individual throttle body assemblies and headers...the list keeps going

Tell me you have a five speed?

[LJSE34]

what would be a good bang for the buck performance upgrade for the M20? (Chip has already been done)

[slocar]

what would be a good bang for the buck performance upgrade for the M20? (Chip has already been done)
listing it on ebay, then buying something else? lol

m20 powAr! :redspot

[323I Junkie]

Which Chip?

JC,Dinan,etc...?

[LJSE34]

I have a JC and a bavauto (I believe they're by autothority) chip. Currently running the stock chip. I just bought a new daily driver so the ol E34 is now my project car. I'm making a list of things I'm gonna do to it.

[slocar]

I have a JC and a bavauto (I believe they're by autothority) chip. Currently running the stock chip. I just bought a new daily driver so the ol E34 is now my project car. I'm making a list of things I'm gonna do to it.
you have 2 chips? sell me one; at a discounted price :devillook

[Striker169]

I too was wondering what the best mods other than the chip were?

[LJSE34]

About the chips, once I've got my E34 running again I'll test both and see what works the best. After that I'll sell one.

I don't think there are too many things you can do to increase M20 performance without banking the hell out of your pockets. I'm going to disable my AC (it's messed up anyway), maybe install an eletric fan, chip, maybe knock a high beam out and do the cold air intake, although I'm not too sure about that one yet.

[xatlas0]

There is lots to do to a M20. E30.net has a bunch of god things. Off the top of my head, stroking it is pretty easy and will increase torque and power significantly. After that, TCD is pretty much done with a M20 kit that pushes it to about 300 of both. Over in the FI section, it just ran a 11.85 on stock internals.

There is much one can do. After doing all that, it should run about 5k in total, less if you do it yourself.

[liquidtiger720]

what would be a good bang for the buck performance upgrade for the M20? (Chip has already been done)
'

you got a chip!?

[323I Junkie]

About the chips, once I've got my E34 running again I'll test both and see what works the best. After that I'll sell one.

I don't think there are too many things you can do to increase M20 performance without banking the hell out of your pockets. I'm going to disable my AC (it's messed up anyway), maybe install an eletric fan, chip, maybe knock a high beam out and do the cold air intake, although I'm not too sure about that one yet.


AC DIsable destroys the value and gets you nothing
Electric Fan gets you nothing-BMW Fan clutch and fan assemblies are extrmeely efficient
High Beam with cold air is almost worthless too

Save your car...do better mods. There are almost no "Free Mods" unless you have an earyly production M20 which you dont


NOw

Some good mods to do:
Mass Air conversion.e34.net is working on one for under $400
New Injectors: ON all older boshc systems I have seen injector upgrades work wonders. Not necessarily on peak power but definitely on power under the curve
ITB: Too freakin cool but hellaciously expensive (2400 I think)
Turbo: Impossible to beat
Cam and High flow heads : You have an M20. Why not go for 8K?
Lower gears :BMW goes all the way down to 4:11, right?
Headers. Adapt e30 headers, theyll prbably bolt in

You can always get mroe power . The issue is ROI

[LJSE34]

AC DIsable destroys the value and gets you nothing
Electric Fan gets you nothing-BMW Fan clutch and fan assemblies are extrmeely efficient
High Beam with cold air is almost worthless too

Save your car...do better mods. There are almost no "Free Mods" unless you have an earyly production M20 which you dont


NOw

Some good mods to do:
Mass Air conversion.e34.net is working on one for under $400
New Injectors: ON all older boshc systems I have seen injector upgrades work wonders. Not necessarily on peak power but definitely on power under the curve
ITB: Too freakin cool but hellaciously expensive (2400 I think)
Turbo: Impossible to beat
Cam and High flow heads : You have an M20. Why not go for 8K?
Lower gears :BMW goes all the way down to 4:11, right?
Headers. Adapt e30 headers, theyll prbably bolt in

You can always get mroe power . The issue is ROI


Thanks for the tips. The car already has no value so I'm too worried about doing things that would destroy its value. Regardless, I should address the suspension first before I get to the engine.

[323I Junkie]

Dont forget you need AC for a good defroster to work

[LJSE34]

About the AC, my condenser is leaking and I suspect my expansion valve to be leaky as well. I really don't feel like spending the money on getting it fixed, plus I never use AC. As far as the defroster goes, I can't really recall the last time I needed one here in the sunny south bay area.

[sydneybimmer]

California gets hot dos'nt it.... Could you be without AC?? Forget that suggestion.

Best mod is regular maintenance, in particular the fuel injection system (not just the injectors). Just had mine done and she again pulls as hard as a hungry Pitbull.

[Gregs///M]

I wouldnt modify en e34's performance unless it was low in miles. It just doesnt make sense to me to upgrade performance on a car that is already worn after so many miles. I can't think of any mods to do that would increase performance, yet not increase the chances of ruining or damaging the drivetrain or engine.

[xatlas0]

I wouldnt modify en e34's performance unless it was low in miles. It just doesnt make sense to me to upgrade performance on a car that is already worn after so many miles. I can't think of any mods to do that would increase performance, yet not increase the chances of ruining or damaging the drivetrain or engine.

Ah, but that is just it. The cars are now cheap enough that one can completely destroy their car and it won't set them back a mint. As loathe as I am to compare it to such, it is similar to Civics. They are cheap enough that a person can completely bomb the car but rebuild it for a minimum of expense. Heck, you can buy a beat-up 525 for 1500$. At that price point, the car is easy to replace.

[323I Junkie]

I wouldnt modify en e34's performance unless it was low in miles. It just doesnt make sense to me to upgrade performance on a car that is already worn after so many miles. I can't think of any mods to do that would increase performance, yet not increase the chances of ruining or damaging the drivetrain or engine.


The m20 I pulled apart with 300K kilometers was perfect as far as bearings and rings. The issue was a worn cam due to insufficient cam oiling

The m30 I pulled apart was in the same shape, but w/o the worn cam. Its worst issue was coking due to a bad PCV system and possible service abuse

Third, its an M20. They are a dime a dozen

[SC David]

Cool thread. I feel like it's never been discussed, since there isn't much use in modding a heavy underpowered car. Ironically, comparing our BMW's to Civics is not too farfetched. They might cost a hell of a lot more to maintain that a Civic, but if you look in the right places, cheap parts can be found. Our M20 E34's are somewhat of a rarity though, given their short three year production run. It is this reason that I think there is relatively little info on our cars. It's easier to turn to E30 forums and writeups for information on performance.

[323I Junkie]

I just looked at the price of ITB manifold from their company, which is www.bmpdesign.com or something.

Although they are a hell of a piece of art..at $2850 bucks they are a Ferrari level piece of equipment. I want to build my own, several people have done it...heres my suggestions

Measure the volume of the plenum of the existing manifold. If you have cams and heads and headers, increase t by about 20%. You can make hte volume adjustable by building the plenum from a piece of tubular stock aorund 4" diameter. and then trimming the ends or adding o them. You can then build a final stage that is "perfect"

Shorten those intake runners to apporximately the length less about 10% of the carbeurated m20 manifolds. Keep the diameter roughly the same as your ported intake ports. Use premade bellmouths to weld into the plenum.

Use motorcycle throttle bodies, you'll have to machine a central shaft.Keep the throttle plate size within 10% of the runner size.


You can get programs like Dynomation to design better, but playing aorund and doing a little research on fabricated intakes will put you in the ballpark. You can tune, by trimming adding, for years. The main thing is rnner length and volume and plenum volume. Whats good for the goose isnt always good for the gander, and a modified 3.2 M3 manifold may be just way to much for a cammed 2.5 12v

[offthewall]

intresting..an ITB m20 e34... i wonder how fast that will go??

[offthewall]

has anyone know anybody that has done a turbo setup on a e34 m20 without the tcd kit?

[xatlas0]

has anyone know anybody that has done a turbo setup on a e34 m20 without the tcd kit?

There have been quite a few custom turbo E30 M20s; you should be able to use those setups verbatim, aside from changing some IC pipe length and other minor changes to fit the e34 body.

[LJSE34]

I think I'll leave it at the chip and spend money on some needed suspension work. It's a heavy underpowered car and I must accept it.

[323I Junkie]

I think I'll leave it at the chip and spend money on some needed suspension work. It's a heavy underpowered car and I must accept it.

]

Quitter. I bet you can have it run a lot better. You can get 220 horses out of the m20b25..you can do 205 easily. Go turbo. IMO, Cartech is going to start making m20 kit again

[AufDeutschBitte]

]

Quitter. I bet you can have it run a lot better. You can get 220 horses out of the m20b25..you can do 205 easily. Go turbo. IMO, Cartech is going to start making m20 kit again

Yeah, don't quit. But Junkie, if you're suggesting turbo, a little more than 200 or 220 will be made. If you do all the other supporting mods of a turbo build and size it right, more like an easily attained (still costly) 275-320whp.