18psi

iTrader: (76)

Its no secret: borgs really like higher pressures

JasonC SBB

NOte that efficiency changes more with flow and less with pressure ratio.

aaronc7

iTrader: (8)

the thing that attracted me to the GTX was that it looks like it might be able to take you to 400whp territory while staying within 0.70 efficiency island. That and it would be a simple swap on my car with no mods to exhaust.

TurboTim

iTrader: (9)

Please post your data backing this up.

Savington

iTrader: (31)

No data, just driving impressions. The 6258 that I drove reminded me of my old BP4W/2554R setup. Crazy, crazy responsive and awesome low-end and mid-range power. I've driven several 2860RS cars and they don't even compare to the way a 6258 drives, and the 2867 isn't going to spool or respond faster than a 2860RS.

Look at soviet's dyno plot - 200ft.lbs at 3000rpm and 250+ft.lbs at 3500rpm. Not even Paul's old car did that, and that was a 2560R car. The EFR6258s are torque monsters.

GeneSplicer

iTrader: (14)

I want my money back for EFR buttsecks, Andrew...

aaronc7

iTrader: (8)

its here

Full-Race Geoff

just a heads up - the efr 6258 are available again

agreed, the mid-range torque and the response of these turbos is their most unique trait. Im addicted, nothing else will go on my projects

TheDriver

iTrader: (2)

My vote goes to the obvious choice......

Leafy

iTrader: (1)

Geoff, any chance of the twin scroll 6258, and if there is, any idea the differences in spool between it and the single scroll.

Full-Race Geoff

Based on my experience - the 6258 is crazy responsive in singlescroll T25 config compared to any of the traditional turbos we're used to. the small EFRs are an outstanding fit for turbo miatas, in fact one of bw's engineers ran a 6258/log manifold on his personal car and LOVED it, until he had to move across the planet and sell his car.

There will be more EFR housings released next year (2013) and SEMA will be the official announcement of what's coming. I do not yet know if twinscroll will help 6258s (there is a good chance much earlier spool would make you compressor limited at surge, but dont know the limit yet and it will be different for different engines).

one nice option is you could purchase a singlescroll EFR and upgrade to the twinscroll housing in the future

Leafy

iTrader: (1)

I think earlier spool would surge limit as well from playing with the match bot, but that would mean it requires less energy in the exhaust gas to spool which would theoretically decrease transient response time. Spool doesnt really concern me as long as I can hit my torque target by 3500-4k rpm, its transients that I want.

Der_Idiot

iTrader: (2)

What I've wanted to see was the 6758 spool data with a twinscroll housing.

blackdbl9NB

I know I am bumping a 3 year old thread, but this came up looking for information on the 6258. Awesome info all the way around, so thanks guys. It's helped a lot.

I am looking at a 2860RS compared to the 6258. Buying from Full Race, there is a $550 price difference between the two turbos. Is the 6258 that much better than the 2860RS? I am willing to spend the money if the value is there.

This will be going on a 91 with a 1.8 swap. ECU to be sorted out, I am still in the early stages of planning at this time.

I am clicking reply and completely expecting to get blasted. Thanks for any info.

Leafy

iTrader: (1)

Yes totally worth $1000 more than a Garrett.

blackdbl9NB

Thanks Leafy.

Girz0r

iTrader: (1)

No comparison between the two. The 6258 dominates the 2860RS in spool & boost.

Support our vendors!

TSE is setup for preorder on their manifold + turbo - $2,000.00

Trackspeed EFR Turbo Manifold 1.8L

T25 Internal WG for maximum spool, v-band is currently only in a larger A/R

Savington

iTrader: (31)

EFR6258 gets a lot cheaper when you bundle it with our EFR-specific cast manifold.

blackdbl9NB

Yeah I was looking at that. Its a hell of a deal. Thanks guys.