Re: 545i? (archive)

I dont know how to put this as I at one point was going to do exactly what you are talking about. You are looking at a project from hell. I was going to do it to a non turbo 7 series so the intercooler, etc would have gone right in, but on the 5 I think thats going to have to be fabricated to not to mention the turbo cool down system, oil cooling system, ducting, oil feed to the turbo and also the fact the ZF22HP has a different torque converter in the 745 and proper gear ratio (2.93) to allow the turbo to build boost without going through gears so fast with quicker and actually making less power, etc. I just noticed you were a 5 speed, you will be even slower but it will work... A couple of other big problems is you need the entire injection system too from a 745 as they go from 38-58+ PSI on fuel pressure and the injectors work this way to compensate for more fuel under boost, not to mention the motronic system itself. Your M30 motor does not have the quality of pistons in the 745 motor either although 9.0 compression will be fine on a hot-rod, but does not sound like your too worried about a car thats destined to a life of $4+ a gallon of gas and one hint of detonation and you will be into the motor. If I were to attempt this myself knowing what I know now, owning both a 745 and a 735 right now, I would buy an entire wrecked 745 with a good drive line and take the entire motor, trans, etc as this is going to be the cheapest and best way in the long run to accomplish what you want. There are so many little different things that you really dont think of until you actually compare the two cars and if you were to just buy the commen since stuff now, you still need 10 times more than you think. I'm not trying to talk you out of it as I think it would be a very neet car but dont expect it to be any faster than a euro 745 as the euro cars weigh 3450 and your american 5 is going to be a little more not to mention the fact it is not a factory produced car and you will never see any return on it.

Hey guys,

I bought a turbo for my car. What I got was the turbo, manifold, wastegate, airbox, and intercooler from a '80 745i. The intent is to install it on my '89 535i 5spd. My shop has given me a rough estimate of $2000 to $2200 for installation. Considering I paid $400 for the turbo and stuff, the price is definately right compared to the Korman, etc. kits. Assuming it works.

Naturally, I've got some questions. The 745i had compression ratios ranging from 7.0:1 to 8.5:1. My car has 9.0:1. Will I need to use low-compression pistons, or otherwise lower my compression? The Korman website says their kits run from 5.5 to 6 PSI of boost, without any internal engine mods. The 745i wastegate allows 6 PSI stock, but it could be tweaked a bit to lower/raise that...

I've been told the stock fuel injection system will be able to supply fuel for 8 to 10 PSI of fuel without mods, is this true? Is there anything I should do to ensure that sufficient fuel is delivered to the engine? Don't want to go lean...

I have a Dinan chip, I imagine I will need to put the stock chip back in. Anybody with an '89 535iM that wants to trade their stock chip for my Dinan? ;) I have been told that the stock chips will allow for 100 PSI of boost by default, is that true?

Anybody want to recommend a good blow-off valve? Are there any wastegate upgrades available? Anything I should know?

TIA,
Joe Ording

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