not sure what to do?

[Zieg]

I have an 87 Euro 730i 5 speed car. I have owned it for a little over 6 years. Car has a little over 200,000 Km. I have taken very good care of the car. Multiple board members have seen this car in person. The car is significantly lighter than most other E 32 6 cylinder cars as it does not have a catalytic converter or cruise control and the seats are manual not electric. I also have owned 6 E 28 533 or 535is. I presently still have an 84 633CSi automatic that I have owned for 14 years. I have done a number of upgrades to both cars besides keeping up with the regular maintenance. Just wanted to give a little history.

Now my problem I want to increase the power of the 730i. It needs more "grunt" . Cory (E30luv318i) installed a chip I purchased from Shogun and it did make a difference especially over 4,000rpm. . . . but not enough. I no longer turn wrenches so what ever work I do decide to do would be preformed by a BMW shop. I have driven E23 745's and that amount of power would be perfect but I am not sure what would need to be done, (ie) does the turbo unit from a M30 B32 fit my M30 B30 motor. what about internals would I need to change the crank and upgrade the rings, pistons etc. to lower compression? I am not looking to swap out engines! My car is very original with some tasteful upgrades. There is an older picture of the car in the photo section of this board on page 7 from 11/16. I am looking for suggestions other than buy another car with a bigger motor LOL. Thanks in advance for any input.

[shogun]

I assume you do not want more top speed, but better acceleration from 0 to ? Change the final drive ratio would be a possibility? https://www.bimmerforums.com/forum/s...rential-ratios
final drive is the easiest and less problematic and probably less costly on the long run instead of doing a turbo installation or other changes on the engine.

[Zieg]

I assume you do not want more top speed, but better acceleration from 0 to ? Change the final drive ratio would be a possibility? https://www.bimmerforums.com/forum/s...rential-ratios

Thank you Shogun that is a good idea and something I will look into. By the way the chip you sold me works awesome! Thank you.

[TheStigg]

An e23 turbo would be loads of fun. Most of the install is nuts and bolts. From what I have read, you can bolt one on with no mods to the engine internals as long as you keep it under 15psi boost, but perhaps it would be wise to at least freshen the head and use a thicker head gasket. You will need at a minimum, larger fuel injectors and a higher capacity fuel pump. The early e23 3.2 liter m102 745i up to about 1982 had 10 psi boost. The later m106 was 3.5 liters with 7 psi boost. Much information in the forced induction forum. Mye28.com also was a good source in their forced induction forum. If you can get to Scottie Sharp's forum with the wayback archive machine, there's lots of info there for turbos. I believe your 730i would have either a 3.64 or 3.45 medium case 188mm diff. You could go with a 3.73 from an early e34 525i for marginal gains or a 3.91 from a pre-1991 e32 735i automatic. If going with a turbo, you would want to go the other direction such as a 3.23 or 3.15. In the end, it comes down to how much money you want to spend. The saying goes, "there's no substitute for cubic inches" so perhaps consider a 3.5 liter swap or a 3.6 or 3.8 liter M5 or M6 motor.

[paulmer]

Caveat -- I've only owned V8 and V12 cars. But:

Put in an S38

But being more "realistic" -- couldn't you swap to a 3.5 engine? I'm sure you (or a performance shop) could get you one, build it up and install for a "reasonable" amount of money. I'm sure a 3.5 block + hotter cam + shorter ratio diff = happy you. If on a budget, you might want to focus on just swapping to a hotter cam and short ratio diff.

And of course you could also go with TheStigg and turbo it, maybe in conjunction with mods above. Really depends on your budget, what kind of characteristics you want (ie, closer to stock, or wilder), etc. Lot of trade offs.

If you don't know exactly what to do, and aren't going to do the work -- why not find a trusted BMW performance/racing shop in your area? I'm sure they could help guide you and take the stress/research out of this, if you want.

[Zieg]

Caveat -- I've only owned V8 and V12 cars. But:

Put in an S38

But being more "realistic" -- couldn't you swap to a 3.5 engine? I'm sure you (or a performance shop) could get you one, build it up and install for a "reasonable" amount of money. I'm sure a 3.5 block + hotter cam + shorter ratio diff = happy you. If on a budget, you might want to focus on just swapping to a hotter cam and short ratio diff.

And of course you could also go with The Stigg and turbo it, maybe in conjunction with mods above. Really depends on your budget, what kind of characteristics you want (ie, closer to stock, or wilder), etc. Lot of trade offs.

If you don't know exactly what to do, and aren't going to do the work -- why not find a trusted BMW performance/racing shop in your area? I'm sure they could help guide you and take the stress/research out of this, if you want.

Thank you both for the information. I will search the forced induction pages on MyE28.com. I have thought about just installing a M30B34or B35 motor but leaning more toward the turbo idea. I have owned several turbo's and I have had good luck with them but all were factory turbo set ups. Am somewhat surprised no one has mentioned supercharging as an option. I loved the sound of the super charger winding up on my R 56 MINI Copper S.

[paulmer]

That is a good point, I don't think I've ever seen a supercharged old-school big/small six..only on modern cars like E46M3. Blowers are a very popular solution for V8 and V12 cars, less plumbing, etc. Agree on sound too -- no turbo to muffle the exhuast

[CroughtonE32]

That is a good point, I don't think I've ever seen a supercharged old-school big/small six..only on modern cars like E46M3. Blowers are a very popular solution for V8 and V12 cars, less plumbing, etc. Agree on sound too -- no turbo to muffle the exhuast

They actually exist. Metric Mechanic for a mere ten grand will ship one of three motors they build. A 3700 and 3800 Rally engine, and a 400 HP turbocharged M30. Just for shits and giggles it really is great reading.

https://metricmechanic.com/6-cylinder-m30-engines/

[Cactuar]

Now I need to clean the drool off my keyboard Great stuff.

[paulmer]

Did you guys check out the MM builds for M88/S38 too I couldn't help myself

Well no matter which direction you go, definitely keep us up to date OP. We want pics/videos/info of build

[htrdbmr]

Come on over to the dark side...

[paulmer]

Come on over to the dark side...

Would love to see more of that. Lot of guys on the E34 forum have done LS swaps. We need to see more LS swapped E32s...Actually, aside from your car htrdbmr, and I think you have a SBC (technically not a LS, right?), I'm not sure I've seen another car

Also htrdbmr, would also love to see some more pictures or a driving video of your car. Don't think I've seen much before