Savington,

Can you let us know how this system spools up compared to the FM II? What about the area under the curve differences?

Erik

Our expectations are significant low-end and high-end improvements with the EFR6258 vs. FM's 2560R. We will have some dyno comparison charts between the two turbos later this summer.

I haven't had time to read through the whole thread yet so sorry if this has already been answered but when would this kit be out? I'll probably end up picking one up when it comes out.

I can not for sure say as I do not work for TSE, but I would expect several more months before we see them. With the EFR's on backorder and the problems they have had I would not expect Savington to be getting any soon.

We'll announce a release date and take pre-orders when we're a bit closer to completion. Before the end of the year for sure, hopefully quite a bit before.

Sounds good. What's the guess as to the price for the complete setup?

Pricing estimate in post 4 is still accurate today. https://www.miataturbo.net/prefabbed...34/#post872073

There's a fair amount of info in this thread, so if you're really interested, reading this thread from post 1 is a great way to get an idea of what we're planning to offer.

The GT25 turbine has to be the worst of the Garrett offerings. I bet is was designed on a commodore 64. The turbo Sav is putting together is in another league altogether. I would expect substantial gains on both ends of the RPM band.

You make it sound like incremental gains in turbo efficiency are a night and day difference.

Transient response is where it's really at.

Pretty much. The 6258 has wheels that are larger than a 2860RS, but it responds and drives like a 2554R and makes more torque down low than either of those turbos could even dream of.

They are when it comes to the GT25 frame. Gains are hard to come by when compared to a well designed turbo. The GT25 frame is not one of those.

Efficiency of the compressor wheel is not the issue. The turbine section is where that turbo falls far short. It's well documented.

Alright, will do. Thanks for the help!

I honestly never really paid much attention to the Borg-Warner turbos, but this is really impressive:

https://www.miataturbo.net/attachmen...ine=1343739892

Red is the EFR 6258, blue is a GT2871R, both in .64 A/R.

Source of data: BorgWarner EFR 6258 Turbo - Full-Race.com

torque curves of my car (red) vs Garrett 2560 /w BEGI IM (blue) vs shuiend's old setup (green)
https://www.miataturbo.net/attachmen...ine=1343756657

bauce

All at same boost of...?

I think they were running lower boost. I was at like 18-19psi up top and 15psi at 3500rpm.

Still, the point is that the curves do NOT intersect. I have more faster spool *AND* more power. My torque curve is like a hat for their torque curves.

My turbo has been on at least 3 different cars for members on mt.net and along with however many 240 people used it before I got it without any turbine wheels falling off. :giggle:

Clearly, it's because I'm *THAT GOOD* at breaking parts.