Most factory cars run turbos with internal wastegates. Most aftermarket turbo kits run external wastegates, which is why you see an extra hole on the manifold to bypass exhaust gas energy. The reason is that the internal one has to be smaller to fit. Sometimes you need a bigger one to control boost. Location and routing also has an effect.
Very do twin turbos on the E36 It is more complex and there is no need. A modern reasonably sized single is responsive on a 2.5-3.2L. If you feel like you must put those antique turbos to use, do it and post how it works out. You might find some posts or threads from people who have done similar things if you search. I vaguely recall reading of some over the years. To me, there would be zero benefit. There is one shop with a very nicely done twin Z3 M Coupe, but it’s all professionally fabricated high end stuff that makes 800+ rwhp.
The advantage i see is the cost effectiveness of the turbos compared to the multi thousand turbos most use. I don't think they're antique, they produce pressure just as a turbo should. Exhaust or pressure side turbine diameter could be not ideal for this application but that's not related to it being antique. Besides that i don't see what makes this turbo worse than a newer model. But i have never turbod an e36 so i'm just fantasizing.
Last edited by importbanana; 12-01-2020 at 01:49 PM.
The design of the turbo impellers 20 years ago is not as efficient as today in terms of aerodynamics/efficiency. You don’t need to spend multi thousands of dollars to get a good turbo, although it is possible to spend over $2k. Some of the Borg Warner are around $600. A Precision 6262 is about $1000 and there are some chinese turbos that are earning a decent reputation if you read widely among forced induction forums.
You could certainly rig something up that would make boost — but what the Audi did 20 years ago is peanuts today. An M50/52/S50/52 with nothing but a compression lowering headgasket can reliably do 500 rwhp. It’s easier with the 3.2 than the 2.5 and more displacement helps boost. The bang for the buck is the M52, which you can find for $500 if you are patient.
Run a tried and true bottom mount like the SPA, a mid size T3 turbo with a compressor around 60mm, a 38mm wastegate, a blow off valve, an inexpensive front mount intercooler from CX Racing or step up to Treadstone, a 60lb ECU tune, and a 3” exhaust and 400 rwhp is easy. Closer to 500 rwhp with S52 cams.
I have a couple of twin turbo cars, but my single turbo E36 will run away from them.
You're probably right, the modern turbos aren't that expensive and they're more efficient.
13 F30 328i Sport 6MT
95 E36 325i Vert 5MT
92 Sentra SE-R SR20DET DET Build Thread
08 E90 328i Sport [sold]
89 E30 325is [sold & missed]
Bookmarks