Should I turbo or supercharge my e31? Which route to go?

[Fatandre]

Should I turbo or supercharge my e31? Which route to go?
Its just to slow in the form of NA

[wgknestrick]

IMO, you are making a mistake both ways on a V12. Build it out to be an NA, equal length header, ITB, sound porn car if you are unhappy with the power. There just isn't enough room in that bay for anything else. Anything you do should be centered around making the V12 shine as that is the real unique, collectible aspect of this car.

[pbonsalb]

It’s slow by today’s sport hatch standards and a porker in the weight department. I’d turbo it to have the torque to get it moving. An LSx V8 swap might be cheaper.

[Fatandre]

There are supercharger setups out There. One guy has 600 at crank

[328iFun]

Should I turbo or supercharge my e31? Which route to go?
Its just to slow in the form of NA

Leave it alone, as is

[milKt]

That thing weighs almost as much as my 1999 Chevy Suburban.

An 850 is a weekend driver.

Find an E36, so you can enjoy the spoils of ALL the existing research and development.

[Fatandre]

That thing weighs almost as much as my 1999 Chevy Suburban.

An 850 is a weekend driver.

Find an E36, so you can enjoy the spoils of ALL the existing research and development.

My car is a bit ligther

Any more inputs?

[GazM3]

If there is an effective supercharger kit go for it. Even though the centrifugal supercharger is technically the least efficient way of FI it’s the best if you want to retain a naturally aspirated type of character.

Ive seen some v12 8seires with twin turbo and they certainly make great power but just lose some character.

[Fatandre]

but With turbo you could also get some insane sound, right?

[JOutterbridge]

Twin Turbos will be loud and very expensive. And not always a good loud. Build it as an NA first with headers and cams. If you still need power then go NA E85 build and then supercharger. Your car just needs an exhaust and tune really. Don't spend 10000 on a turbo setup unless you plan on drag racing or something

[e30polak]

Really depends on if your 8 is manual or auto. The auto makes things tricky with turbo, as the exponentially greater torque may overpower what that terrible and heavy automatic can handle. If it's manual, I'd say a custom single turbo. Twin turbos are very hard to package in that engine bay. Turn the exhaust manifolds forward like the F-body Camaro guys to and run a turbo up front and low.

The biggest hurdle outside of packaging is tuning. To go turbo you really want a standalone, as the factory DMEs are very poor technology and trying to tune 2 (or 3 if you have an m73) will be a nightmare.

Obviously turbo can cost a good bit more, especially if you don't do your own fabrication. That being said, you can really choose how you want your turbo power to come on depending on the size of the turbo. A single Holset hx40 or hx50, or a Borg Warner S400sx3 series turbo, would be great single turbo options and give you plenty of room to make power.

If you were to go turbo, you could more easily package them by converting to a custom M8 style headlight by putting by xenon projectors with HIDs into the bumper lights, and get rid of the massive flip up headlights. I had an 8 series I was going to slap an iron block 5.3L LS into and do that exact thing, by going dual top mount turbo, and putting 1 turbo on each side where the factory headlight housings sit.

All that being said, if you were to swap in a proper LS engine, or an S62, you would probably be better off in the long run.

- - - Updated - - -

Twin Turbos will be loud and very expensive. And not always a good loud. Build it as an NA first with headers and cams. If you still need power then go NA E85 build and then supercharger. Your car just needs an exhaust and tune really. Don't spend 10000 on a turbo setup unless you plan on drag racing or something

The v12 engine responds poorly to head work, camshafts, etc. Many have tried and it's a big waste of money because the engine itself is very inefficient.

[GazM3]

If there is a supercharger kit out there with an intercooler get it.

Like all kits u may need to finish off the kit especially with the tuning.

lovely looking car. Btw

[Matt Cramer]

Is it wrong that I want to see that car with a hole cut in the hood for an 8-71 Roots blower? That would solve the "no room under the hood" problem.

[328iFun]

Is it wrong that I want to see that car with a hole cut in the hood for an 8-71 Roots blower? That would solve the "no room under the hood" problem.

Wrong.

If I had a V12 8 series, depending on the mileage. I would either

Park it / drive it on weekends

or

(higher mileage) clean it up, weld in an unrestricted exhaust, and then drive the hell out of it.

If I wanted a blower sticking out the hood I'd go domestic

If this were my car it'd be my DD

But all in all -

what is the 12 worth on an auto anyway?

And a few guys I've talked to say "whats the BMW V12 worth at all"

[Fatandre]

Its a V12 manual transmission

[1000hp]

Dinan did it.
They may provide you with the information you need, since their kits are no longer available.
http://www.jrwappel.com/my-rides/1991-dinan-8

[bubela]

Neither.

[Fatandre]

I am starting to lean more towards the Turbo option

[GG///M3]

Neither.

This.

[jimmyz66]

Turbo, if possible. More expensive, but more boost options. I have a built s/c E34 540i/6 and would love it if it was turbo'd. But, S/C was easier to install and fab up. Still, either way is the fun way, gotta love boost, and in my case with fully built 4.9L M62 engine.Wish you good luck on your quest Luke Skywalker.

Edit: I went turbo.

[hsvturbo]

I am starting to lean more towards the Turbo option

I would go with two rear mount turbos, a small muffler pre-turbo and no muffler post turbo. The sound of the turbine would be heavenly.

[JOutterbridge]

I agree. You don't have an auto and you want power go mid size single or twin. Yes it'll cost more but setup properly it'll be a sick build. Expect to pay a lot though because standalone Ecu's and turbo part/fittings really add up

[digger]

a few NA bolt ons would have the most character

[Fatandre]

a few NA bolt ons would have the most character

like what?

[hotdish]

Found an ancient thread from someone who built a TT 850: https://www.bimmerforums.com/forum/s...-streets-of-DC

Looks like John in DC also sells supercharger kits so you might want to try to contact him.