blown 944

Yes in that sweet spot it would, but you have to look at the area from surge over to the sweet spot moreso. You want to have the majority of your plot in the sweet spot not just the highest volume of air. Also in this thread other factors were important and initially the comparison was with a 60 trim

I want to be clear that I am trying to keep this w/i the context of this thread.

The parameters were ~300-325hp at 15psi with fast spool. I will absolutely agree that the 50 trim is the better all around turbo but for quicker response the 57 works for this app.

to really drive this home you would have to plot at ~ 15 # (~ 150 hp) and plot that at ~ a 2.0 PR ~ 15 psi of boost starting. On the 50 trim it is left of surge while the 57 is within the map.

It really is semantics between these two units IMO B/C a few hundred rpms doesn't mean much to me but for those looking for THE quickest spool and holding 300-325 I think the 57 is the one

Techno Duck

I am far from a expert in turbo sizing, but based on what ive read the 57trim seems to meet my needs hence why i will go with that. So between the 50 and 57 trim, for comparisons sake what are going to be the differences between spool and power delivery?

blown 944

My experience as stated earlier is the 57 will build pressure earlier and will have a more "power" feel in the transient stage (1-15psi) but will fall off at higher boost levels.

The 50 will not feel quite as torquey in that area but will hold boost further and higher.

the 60 trim is even more torquey but falls off even worse.

I have ran the 50, 57 the super 50 and the super 57 all back to back and my favorite was the super 57. The difference of the "super is the exducer size is 3.2 vs. 3". The super series are labeled as the same trim but are really more like a larger 40 or 46 trim wheel (very odd labeling)

White_951

I keep reading and re-reading this thread and as it is 4 years old I'd like to bump it up and revisit this conversation...has anything changed/been introduced in the last 4 years????

My 26/8 is great for throttle response but I have a feeling it's going to suffer on the back straight at Sebring.....

bumper87

go 27/8

Dave W.

I have my eye on the Precision billet 5558. They just came out with a new CEA turbine wheel that's much lighter and flows better than the previous stage 3 turbine wheel. I haven't seen it in a KKK housing, so for now it looks like it'll need some fabrication to fit.

lee101315

I agree. That is the best turbo for the money on a 951, hands down. I ran turbo on my last 951 with a lindsey/maxx hp chip, barn door AFM @ 16 psi and the car was fast, responsive, and reliable.

Scott H

Back when they were using Turbonetics F1 turbines they told me a Turbonetics replica hotside would either be a direct fit or could be machined to work.

Rogue_Ant

A K27/8 will definitely be slower spooling, especially in transient situations.
I have a K27/8 on currently, previously I had a K27DR (/8 turbine wheel in a /6 housing) and like it much better for a street & occasional track-car.

A LR S48 or S53 would be a much better choice for a fast-spooling, decent-power 951, IMO. (yes, I'm ignoring GT/GTX turbo, because they are not a bolt-on proposition)

White_951

Yep, I've been eyeballing that LR Super Series.......I want this curve in the 350 neighborhood....

Paulyy

that wont be possible on a stock head and cams.

refresh951

350ish can be obtained with stock head and cam.

Paulyy

no no, talking about the curve, i know 350ish can be obtained with a stock head a cam

Not that torque curve, just can't see that happening.
well you can if you run more boost and pull a lot of timing to loose power and make a straight torque curve, but that's just silly.

White_951

I think I've got the head work and cam covered......

Paulyy

i'll be interested when you choose a turbo to see the power outcome.
what head work do you have or going to get done?