745 turbo specs n anyone?

[Jose]

Hi guys,

I was offered an M102 engine today in parts. Everything is complete , except for the electronics, but that's no issue as the loom and computer from the E30 325i can be used with a program adjustment.
I really don' t know much about this engine except it' s supposed to output 252 bhp with only 7-8psi.

Does anyone have experience with tuning these engines before, are they reliable and what about the 3K charger? I' ve heard of these before, but don' t know anything about build quality and reliabillity.

The engine is for my M3 E30 as I sold my nearly completed M3 turbo spec-engine to a costumer for way too much money, so I couldn' t refuse but it' s " heartless" now.

Thanks bimmernuts.

[niall]

i have always been interested in the 745i turbo aswell,
i havent had any personal experience with them because
i have always been put off by people telling me about their
poor reliability, i guess its a good place to start for a turbo
set-up, but i would personally just build a kit up, because
the KKK turbocharger they use does have reliability issues,
so you would really wwant a garret instead also the exhaust
manifold design is far from ideal.

[Jose]

Another compressor is not the issue, it´s just that the compression ratio is very interesting and I will save a lot on loose parts. Th M30 I was building for my own set up cost me over 3 grand in parts, and that´s without a compressor, intercoolre or other ****. I already have a tubular manifold of our own design, so that´sok too. I can buy the 745 package for a mere 400 US, so that´s why it is so very interesting.Thanks for your input though.

[niall]

sorry, my input wasnt very helpfull, i didnt realise you were so clued up on it,
i reckon for 400 bucks its a dam good buy, what specs are you after, i have some info.

[Interceptor]

Another compressor is not the issue, it´s just that the compression ratio is very interesting and I will save a lot on loose parts. Th M30 I was building for my own set up cost me over 3 grand in parts, and that´s without a compressor, intercoolre or other ****. I already have a tubular manifold of our own design, so that´sok too. I can buy the 745 package for a mere 400 US, so that´s why it is so very interesting.Thanks for your input though.
"The 745i's have been much maligned as maintenance nightmares, but aside from the high maintenance nature of any 7-series, the only additional maintenance is the turbo and it's affiliated systems. Parts are becoming scarcer all the time, but I have yet to experience a problem getting any needed parts."

Source: http://members.aol.com/turbo745i/

[JAlfredPrufrock]

It's going to make your M3 way too nose-heavy.

[Jon K]

It's going to make your M3 way too nose-heavy.


The difference is basically the 745 has different oil routes for the turbo etc. Its lower compression. I think M30 is 9.0 the M102 may be 8.5 or 8.7 not sure. With a boost controller and upgraded diverter valve you can make silly torque.

[Jose]

You understand my brainstorms Jon. It´ll be a complete wicked motor when fine tuned, I guess 300 bhp will be in clear sight. Compression seems to be 7,0:1 for a std 745.

[Jose]

As for the nose getting to be too heavy, it won' t. The engine will be positioned far more back than on the Alpina B6 E30 series . I' ve done the M30 into E30 build a few times and was pretty impressed how the car handeled itself with the extra weight. Just push back the engine as far as possible by pushing the firwall in by 5 cms and you' ll be in the clear. It won' t be as the factory intended it, but it' ll be much faster than the original M3.

[JAlfredPrufrock]

As for the nose getting to be too heavy, it won' t. The engine will be positioned far more back than on the Alpina B6 E30 series . I' ve done the M30 into E30 build a few times and was pretty impressed how the car handeled itself with the extra weight. Just push back the engine as far as possible by pushing the firwall in by 5 cms and you' ll be in the clear. It won' t be as the factory intended it, but it' ll be much faster than the original M3.

I look forward to seeing it then.

[niall]

this sounds like an interesting project, yeah your 100% with what you said about alpina mounting them way to far forward, if you keep it low and back to the firewall like you have i dont really think your handling wil suffer. as for 7.0 that is extremly low isnt it, you would want at least 1 bar to really pull the power out

[Jose]

yep14psi is the way to go. Thinking about tossing away the 3K compressor and getting in a new Gt28BB garret. It just depends on the finances, I´m currently restoring the car and even doiong it all myself including the spray over, parts don´t come cheap. I expect to be able to post the finished project in 1 month .

[niall]

is that the same turbo on a 22b imprezza?
parts dont come cheap, dam right. on my wages mate
i cant afford to do jack to my cars,
any pics of the current project

[Jose]

really wouldn´t know. We used this one before on the bi-turbo set up as the first turbo in line and it gave very good results. I wish I could post pictures, just bought a sony cam but my pc just doesen´t want to accept the cam´s software. Even brought in a computer wizzkid and he told me the whole pc needed to be programmed, so that´s not a priority now and don´t have the cash to spare.

[niall]

god dam sony!!

what is the predicted power out put for this set up,
are you using a tubular exhaust manifold
or the cast stock one?

[Jose]

I' ll be using a self made tubular. According to the flowbench used by my father in law, it flow better than the cast one. If you keep the set up std, 250 bhp is to be expected, jsut as the factory claimed at the time. But, as the possibily exists that the GT28 bb is to be installed and boost will be approx.14 psi, I reckon 300 bhp is in the pocket. I don' t expect it to be a bullet of the line as the ration is only7:1, but a bit of fidling with a Apexi or a Turbonetics timer will make it all goooooood....If it works out right I' ll be pissing my pants of laughter when seing the surprised faces of the scooby drivers...

[niall]

i reckon a tubular manifold is worth 25 to 30bhp,
the cast one is a really bad design