My 4-door build

[1991 E30 M42]

Volvo 740turbo. Its a 4 cylinder and it made good power from the factory when you increased the boost pressure. The biggest problem with using a turbo off of a junkyard car is going to be shaft play and burnt-on oil form people not letting the car idle after driving it to allow the turbo to cool off.

[EducatedFool]

I'm looking to make my own kit for as cheap as possible, w/out missing any components. i probably will end up buying a turbo from someone rather than getting one from a junk'd car (unless i find one in really good shape). How would I go about getting a manifold?

[Abrax]

The general problem with turbocharging the M42 is the EMS . As stock ECU uses AFR to meter how much air is there flowing Your engine, You need something related to the pressure made there by a turbocharger. So You need MAP related EMS. And as the M42 is the distributorless system, You need the EMS capable of controlling ignition as well...

For now the cheapest EMS I've found is http://www.vems.hu - It's an open project with it's pluses and minuses, but generally it works, it is cheap, and completely configurable. Check wikipedia for great documentation...

So If You want to turbo this car cheaply, You should go rather big turbocharger, use custom built exhaust system, with as low restricting flow as possible, to avoid going into big pressures. Remember - You make the power by the air flow through the whole engine system, not by the pressure itself. Then Use as big intercooler as possible to keep the air temperature low all the time.
Going big, means low restriction and ability to stay with stock C/R - and as it is 10:1 in our engine it means that You won't be able to go higher than 0.6 BAR in the intake manifold without detonations in the combustion chamber...

This should let You achieve 220-250 Hp's... Which is still not too much for the transmission, clutch and the braked to change for more durable ones...

In that powerlevel some says that it is better "just" to tune the engine well... The truth is that with proper tuning You can stroke, bore, use stock EMS and more agressive cams and You will achieve the same powerlevel without a lag specific behaviour.

But nor low restricting turbo nor highly tuned engine isn't cheap.

In cheap turbosystem You can use Your stock pistons. You just need to cut them on the lathe to lower C/R a little bit. Then go VEMS or one of the last generation of the MegaSquirt /if it supports ignition control/, then use bibbig intercooler and there You are with the cheapest possible option I know will work. But the engine before the modification has to be in perfect condition...

Volvo 740 has a diesel engine... And this is a small diesel engine... So it will probably end acting as a turbocharger just below 3000RPM's... When You will go above this turbocharger will have definately too low flow to act there well... It would rather chop Your exhaust system well enough to guarantee You some nice detonation problems and no powergain...

But theese are my private thoughts...
Check them well...

[Abrax]

Ah, Manifold -> try buing 666manifold as jon, makes them really perfect for reasonable price. check to find on http://www.e30tech.com

[Tor Arne Kaasen]

hey volvo 740 turbo is a 4 bagger gasolin( not disel ) 2,3 liter, ok IC, Garret TBO363 T3 turbo A/R 0.48 ex and A/R 0,42 comp. Smal turbo for a 2,3 god for 1,3 bar max. Ok for m42. butt slow spool up, and smal turbon weel on comp side. the biggest prob is ecu and turbo manifoil.

[Abrax]

hey volvo 740 turbo is a 4 bagger gasolin( not disel ) 2,3 liter, ok IC, Garret TBO363 T3 turbo A/R 0.48 ex and A/R 0,42 comp. Smal turbo for a 2,3 god for 1,3 bar max. Ok for m42. butt slow spool up, and smal turbon weel on comp side. the biggest prob is ecu and turbo manifoil.

Ah, right - I was thinking about my grandfather's old car... It was a diesel...

That kind of turbocharger will spool quickly /M42 is rather high flowing engine despite 1.8 displacement/ and produce power down low, so it will radically raise the torque -> so there is the risk of clutch change necessity.

Of corse there are many schools of turbocharging vehicles.

I personally like to have my powerband just before the red line, so most often I think about a turbocharger with as big A/R as needed to work just up there with enough flow to keep my goals.

But this is surely less driveable around 3k RPM's than the volvo turbo...

Anyway - As I remember there was a company in Germany which produced the M42 turbokit, with all needed items, which transforms the stock engine to about 215 rhp's... It was something around 3000EURO's for the kit few Years ago.

I will search to find the producer...

Turbo manifolds are really rare to this engine, so mainly people need to let them done. I'm sure that You will find well enough qualified welder in Your neighbourhood to weld You manifold. Just search the pipes at Your local muffler wholesalers or shops.

[EducatedFool]

Thanks for all the great info you guys are giving me. I know that there are turbo volvo's here that are gasoline engines. I think I will look a little more into that turbo. I will probably go w/ 666 to get a manifold made. That's the kind of thing I want to make sure is done right. Right now I'm looking to buy another engine so that I can rebuild it and make sure it is just right for a turbo. And new clutch and flywheel are a must for the way I drive

[Abrax]

Thanks for all the great info you guys are giving me. I know that there are turbo volvo's here that are gasoline engines. I think I will look a little more into that turbo. I will probably go w/ 666 to get a manifold made. That's the kind of thing I want to make sure is done right. Right now I'm looking to buy another engine so that I can rebuild it and make sure it is just right for a turbo. And new clutch and flywheel are a must for the way I drive

Be sure to buy stronger clutch plate - it will raise allowable torque and make Your clutch disk live longer -> ask about Sachs sport clutch plate.
And - > beware of steel clutch or things like that - they are really tough, but they can damage Your tranny and differential much sooner. They are there just to be a substitute for 3 disk clutches in a time where there is no money for multidisk plate wchich are the best known sollutions...