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EFR 8474 review?

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I couldn’t seem to find the webinars about the EFR 8474 that you guys said you did.

Story is I have bought EFR 8474 for my R34 already, and waiting for it to arrive. I’m planning the engine build list and don’t know what cams to choose because I haven’t seen any back to back comparison with 8374 vs 8474 1.05ar.

Hi Eugene, the 8474 we have is still waiting to be fitted to our RX7 unfortunately so I can't really offer much direct experience with them. Since they are still relatively new there's limited real world data on them so far. In comparison to the 8374 though, the dyno tests I've seen show the 8474 delivering more power everywhere with better response. It appears BW have really out done themselves with this turbo!

From your blog you mentioned about your RX7 Build https://youtu.be/gAYeEBFeK4Y when will a detailed webinar on the choice of ECU, Turbo, and Tuning Class be available?

Any updates or comments on the EFR 8474 turbo? Basically I'm trying to pick between a single turbo setup for my BMW 1M built for the circuit. The goal is 500-550whp on 98Ron using a Dynojet (STD correction). I'm looking at the G30-770, G30-900, and the EFR 8474. The EFR for sure is a bigger turbo (about a frame up) more comparable to a G35, but if you look the compressor map of the 8474 it looks really efficient at lower pressure ratios. The 8474 flows really well at lower boost while spinning at lower shaft speeds, which seems to be great for a build like mine on 98Ron. The G series turbos seem to really like higher boost pressures of say 1.5-2 bar (guage pressure) which isn't as great for me on 98Ron.

I guess the question is more like I think all of these 3 turbos will make the 550whp, but it's a question if it can be done on 98Ron with great boost response and boost threshold for circuit racing on tracks that have many 2nd and 3rd gear corners.

The ability to make above 550whp is just icing on top if I decide to build the motor and run higher octane (ethanol etc) later.


In my experience 8474 is excellent turbo as well as all BW turbos. There is only one thing they don't like when highly boosted- incorrect positioning of external bypass valve. I would go with BW.

8487? You mean 8474?

What's your take on this 8474 in a circuit / mountain (watch some of those Japanese Best Motoring videos, my mountains here are exactly like that) application in a 3.0L engine? Responsive?

Yes, I mistyped it. It's very responsive on 3L engine, absolutely love it.

Sorry I'm not familiar with your car. You're running an 8474 on what car/engine? Roughly where is the boost threshold and what rpm does it "come alive" in your car?

It's Toyota Mark 2 with 2jz-gte vvti. It comes on boost around 3000 RPM, make 1.5 bar of boost around 3500 RPM and keeps 2 bar boost pressure all the way up to 7500 RPM..

That sounds quite awesome actually. 1.5bar of boost for this turbo is already quite big power!!

Bear in mind the the figures I gave were made on E85 fuel with turbine housing AR 1.05 T4 twin scroll.

Understood thank you. It feels like the turbo should be at that borderline of just right / too big.


This video is a good reference of the roads I drive on. Start at 14:00 into the video. A run like this except for about 10-15min "laps" and not 2 minutes. This car in the video has shorter gearing and the engine revs 2000rpm higher though.

We usually reply within 12hrs (often sooner)

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