Which Turbos for the Biturbo? - The Unofficial BMW M5 Messageboard (m5board.com)

schlumpf-nu · 16th October 2009, 23:00

Hay,

which Turbos from free trade fit on the B10 Biturbo?

Nevertheless, the original turbochargers of ALPINA are too expensive a little (2.500 Euro/Stück)

In the meantime, the more modern loaders are equipped with ball bearing and have no more sliding bearings.

Who has experience with this problem and can give me here a few tips?

Ferrari-Bmw · 16th October 2009, 23:30

Quote:

Originally Posted by schlumpf-nu

Hay,

which Turbos from free trade fit on the B10 Biturbo?

Nevertheless, the original turbochargers of ALPINA are too expensive a little (2.500 Euro/Stück)

In the meantime, the more modern loaders are equipped with ball bearing and have no more sliding bearings.

Who has experience with this problem and can give me here a few tips?

Hello Thomas,, this is the most sensetive and secret discussion of all ,, between BT owners,

unbeliveble how few are able to tell their story,,

i would go for Gt25 from garrett,, and do some indevidual , change,, with new turbo i am sure your car will be a lot quicker,, and getting more power,,

I am searcing all over the internet about B10 BT knowledge,, this swedish company .. PPF
they are a master genious in all kinds of turbo knowledge,, i have asked them ,, and nothing have happened,, on the forum i asked also,, my post was deleted

in USA there is a good company ,, cant remember the name but Dirk Mainka have bought some small things from them with good result,,

ask him and also them,, if they can find a good solution for replacing the oem BT turbo,, i called them ,, and he said that there is NO INFO for them,, to search on the internet, no GARRET official partnr,, about the t25 turbo for ALPINA,, why ----->> the turbo are a special made
(for ALPINA only )

i want to use a Gt 28 or Gt25 or a similair setup ,,the only thing that could be a problem ,, is how the management of the ECU will behave,, i dont know if there should be a problem,,
i think that the BT engine is a good candidate for minimium 500 ps

The tuner Mr.X had a BT for many years ago.. he said to me that he made some HEAVY turbo conversion for many years ago,, with 1.4 bar and te car was at least 500 ps,,,,,,, smoked them all on the autobahn

cdnalpina · 17th October 2009, 04:48

As I understand it, you will have to remap the ECU if you do the upgrade - even if you change out the injector for bigger ones, there comes a point where you should remap. These are all pearls of wisdom passed on to me by others who have tuned their cars.

I am planning on eventually doing the injectors, FPR, fuel pump, turbos and exhaust. I want to run something like a GT30. In speaking with the Garrett rep in Canada, you can get the GT30 in the same dimensional housing as a GT25. The key question is, what did Garrett do to the Alpina specific GT25 to make it unique? If push comes to shove, I'll just get rid of the Alpina exhaust manifolds and get some tubulars made. Likely new manifolds and GT30s would cost as much as going with new Alpina GT25s and you get newer turbo technology and an arguably better flow regime through the exhaust manifolds.

Good luck with your quest - let us know how you make out!

Alecci · 17th October 2009, 10:50

What flanges are on the standard turbochargers?

If they fit, I could recommend the Garrett GT2860R-707160-7 or an equivalent. They are frequently used on Skyline-engines, they have a low boost threshold, spool quickly and pull strong. Used in pairs they are able to support about 540 PS on the GTR's 2.6-litre I6.

There are other turbochargers in the same range that performs very well, for example the GT2860R-5 (about 620 PS) and the GT2871R-10 (about 760 PS). Even though they're usually most suited to 2.8-litre engines and bigger, I used the latter ones on my R34 GTR. On a rough mapping I made 384 PS at only 0.5 bar with boost coming in around 5000 RPM. They usually work gorgeous on 3.0-litre engines and I have no doubt they would be smashing on a 3.5-litre one.

All of these three alternatives are both oil- and watercooled. Custom fabrication of either heat exchange system is not difficult if you just find suitable locations for supply and drain. I custom built my turbocharger oil and water cooling systems on the R34 GTR with no previous knowledge, using high-quality heat-resistant hoses braided with stainless steel and machine-pressed couplings.

I guess the manifold flanges should be the same on the Alpina B10BT-engine and the Skyline GTR-engine, but I'm afraid the downpipe flange may differ. If you're planning on changing exhaust, however, you shouldn't experience any problems having a custom downpipe made for you.

After changing the turbochargers and adding supporting mods a remapping of the car would certainly be advisable. Surely the car will run without a remap, but upgrading the turbochargers and not remapping afterwards would be a waste of money in my opinion. It may also put stress on the engine since boost threshold, etc may be significantly altered in comparison to stock units. For example, having the engine running lean when coming on boost could and probably would have catastrophic consequences for your engine.

Ferrari-Bmw · 17th October 2009, 10:58

Quote:

Originally Posted by cdnalpina

As I understand it, you will have to remap the ECU if you do the upgrade - even if you change out the injector for bigger ones, there comes a point where you should remap. These are all pearls of wisdom passed on to me by others who have tuned their cars.

I am planning on eventually doing the injectors, FPR, fuel pump, turbos and exhaust. I want to run something like a GT30. In speaking with the Garrett rep in Canada, you can get the GT30 in the same dimensional housing as a GT25. The key question is, what did Garrett do to the Alpina specific GT25 to make it unique? If push comes to shove, I'll just get rid of the Alpina exhaust manifolds and get some tubulars made. Likely new manifolds and GT30s would cost as much as going with new Alpina GT25s and you get newer turbo technology and an arguably better flow regime through the exhaust manifolds.

Good luck with your quest - let us know how you make out!

As i speak,, my ecu is programmed to 1.2 bar,, i can change the injectors,, and will probably go to 440 cc,,

your point there is imo the key in new turbo technology,, the backpressure of oem T25 GARRET ALPINA turbo must be enormous at high boost
and thats why the new turbos are often bigger,, and can give so much better flow

i agree also to change the exhaust manifold,, there are blended opinions about that,, but for 20 years ,, the BT was in the lead with the old tech,, now the time and knowhow in turbo tuning is flying forward,, it is all about how much air you can get through the combustion chamber,,

to of my friends are running 1.5 bar on stock smallblock M20B25 and getting ~~ close to 400 ps and over 500 nm,, think about that in a E30 that is around 450-500 kg lighter vs the BT one of the car is getting 12.01 at the drag strip ((on slikcks )) and the speed is over 120 mph
the other is getting 12.6x on vinter tires and 116+ mph, that car is running 3.25 rear axle

i will search ,, well before i start,, and i think i will take the COMPLETE system .. from cylenderhead and after CAT,, and replace it,, keep the oem in the garage,, and bolt on the new system,,

it all depends how much €€€€€€€€€€ i will need and have,, nothing is sure at these days,, at least not here in Iceland

schlumpf-nu · 17th October 2009, 12:49

Hay,

I have in mind no big tuning.

I would like to cover only the Turbos from where differently. With ALPINA a piece costs 2,500 euros.

The complete offer about the installation of two Turbos with work would like to have ALPINA more than 6,000 euros.

Mr. Noelle had changed to his time the snails of Garrett T 25, so that the loaders make earlier the pressure construction. In the exhaust gas side

snails of the T22 are in it, therefore the loader already responds in the lower speeds earlier.

If I mount now state kind T25 Loader, I will also have to fit the injection in. The engine should have with full load to a Lambda value of 0.85.

Thus is guaranteed which the engine does not overheat and cannot burn out.

In Germany there is a company. the control device accordingly can adapt.

The loader GT 2554R would correspond almost to the existing loader.

The oil pipelines would have to be changed.

I have ordered a loader sometimes to the view.

Here on Monday I can put pictures.

Also I plan to mount bigger exhaust gas elbows, there I have found auc a company, them this Producing.