eclou

I have to agree with George. Something is suboptimal. I have never seen a K26/6 put down more hp than tq (perhaps because of Dynojet measurements). I have never seen a K26/6 put down 270rwhp at 16# boost (especially on a Mustang dyno). Also tq peak should be far earlier than hp peak. My K27/6 above peaks tq at 3k or less, and the K26/6 should peak even earlier. There is usually a good 2000rpms between the 2 peaks, regardless of tuning. Either you have a leak, or more likely it is some kind of K26/8 hybrid/cheater turbine. Add another 2-3# boost and you will be at 300rwhp if the HG holds (far too lean).

944CS

stock torque peak is 243 fl-lbs @3500 for the k26/6.......the 26/6 should be fully spooled by 3000, at the latest...did you change cams when you did the head work?

eclou

The stock torque peak is generated so high b/c of the slow roll-on properties of the stock chips. With aftermarket chips and a good MBC/WG it should hit hard by 2700 rpms.

George D

Eclou,

That is a great dyno sheet. That car must be a blast to drive.

George

jgporsche

I have to agree with everyone saying something is wrong....

My 26/6 dyno chart:




Car: '86 951- 146K miles

Mods:

72# injectors
3 bar FPR
Lindsey DP wastegate w/ manual boost controller
Vitesse Maf
Vitesse chip/board
smt-6
forge bypass valve


*note*
STOCK exhaust with ORIGINAL cat.

eclou

It certainly is fun, but all credit goes to Tony G for the amount of K27/6 guidance he has given here. I would have never imagined what a hoot this relatively cheap combo is.

PorscheDoc

Stock cam (that is soon to change). I am going to go with the wastegate theory problem, as that seems most logical. I will throw the Tial on and see how the graph looks afterwards.

With the old motor, when it was moderately healthy, it made 252/270, so yes the tq was higher than hp, and higher than it is now.

It is a stock 26/6, no modifications, this I know for a fact.

We will see how high this worn out old turbo will go before upgrading

I think the late torque is also partially an issue with the tuning of the chips that is currently in it.

George D

Eclou,

Do you mean Tony Garcia out in California? Sorry to go OT. I'm building a 3.0 968 RS spec motor with the goal to have your dyno with another 150hp and tq. We'll see how things pan out.

George

JE_951

Eclou: I put down 273RWHP at 15psi (15.3psi max) on a dynojet. I think that even on a mustang dyno and 1psi more that I would be close if not at 270rwhp on a mustang dyno. Mods in sig, nothing "abnormal".

But I do think that the dyno is kind of messed up. Im thinking that maybe his WG is SOOO bad that it doesnt hold boost at all until about 2800rpms and then maybe starts making boost? that would be a long shot though. But could be possible?

heres a graph from my dyno:

http://i28.photobucket.com/albums/c2...4DynoSheet.jpg

PorscheDoc

Who is making the tial adapters currently? SFR? Looks like I will need to order a set, lol.

George D

SFR had the tial adapters, or Tim will make you them.

George

eclou

270 is awesome for a stock 26/6 at 15#. I could not get more that 260 +/- 3 hp from mine with a MAF, Tial, MBC, 3 bar and Guru chips. The tq would keep going up with added boost but the hp pretty much maxed at 260ish. It is quite possible my old 26 compressor was losing its legs.

One would think that a bad WG (weak spring) would bleed more at higher pressures, but who knows? 270 on a Mustang is probably close to 290 on a dynojet.

JE_951

true true. Maybe I couldnt reach 270 on a mustang. Before mods I was at 313RWTQ at 19psi. I bet at 19psi with my current set-up I would achieve about 320RWTQ (give or take 5tq) with maybe a few HP. max HP was at 5550rpm for me and at that rpm I would need about 255rwtq. Im not sure if my turbo is running out of steam at that point or not to creat enough boost for that tq level?

But back to the original post, I can almost guarantee that either there is a major boost leak or WG leak or that the dyno sheet is not of a 951.

mwc951

K27/6-7200 w/ VR chips, 20psi on 100 octane

PorscheDoc

I am not sure quite how to read into that statement, but you are welcome to come to my shop and I will dyno the car in front of you. If you are questioning my integrity, I am highly offended. I posted the graph to ask for advice, not to be questioned.