brad-cam

For the records, I put the 951 on the Dynojet dyno today to see what she'd do. Recent mods included a Vitesse MAF+Chipboard, SMT6 and K27/8. The car also has a Tial 38mm WG, SFR 3" catback, factory cat converter. Max boost was about 16 psi.

The best run was 284 rwhp, 290 lb-ft torque. A little disappointing, but the car is really quick. The first run was 275rwhp so I played with the fuel a bit between runs to reach the best one. I think I can probably tune a little more power in with the SMT6. The first run (275 rwhp was with a blank map in the SMT6).

By comparison, this same engine last May with stock AFM, Guru chips, K26/6, stock WG and 15 psi boost turned in 217 rwhp/227 lb-ft torque on a Dynapack dyno.

Comments ?

RKD in OKC

Looks nice...

You should be able to run 17psi all the way to red line with the K27/8. That's what my K27/8 would fall off to when I set the boost at 21.

brad-cam

The dyno didn't have a boost connection unfortunately, but with my simple Reliaboost MBC set at 16 psi and using the Tial in single-port mode, I think I might be losing some boost (comments?). I'm going to try a dual-port MBC sometime, like the one sold by LR and Paragon, to see if that makes a difference.

shaheed

hmm i made quite a bit more power with a vitesse setup (older chips not the board and smt6) and k27/8 at 15psi. you don't see horribly rich or lean, what's the compression like on that motor? what gear was the run done in?

brad-cam

Shaheed, dyno run was done in 4th gear. Compression is not great in this motor, I don't think. If I remember correctly, it's something like 135/135/130/118. Cylinder 4 is suspect. The motor was recently rebuilt by me and I may have screwed something up. It runs fine and holds 16-17 inHg warm idle vacuum which I know is a little low. I'm just gonna drive it for a while - it's plenty quick for me. I've got a fresh rebuilt motor on the stand... :-)

aeronautica86

to either of you, (Shaheed or brad-cam) since yall both have the k27/8 with vitesse software, how quickly does the turbo spool - how quickly can you reach full boost?

shaheed

brad that may be it, i was just curious since i made some 30rwhp more with a similar setup but that motor was in really good shape. aeronautica86 i didn't log boost when i dynoed that particular car, but it hit a torque peak of 314 rwtq at 3500 rpm (boost is set at 15psi). so not the fastest spooling thing around (but that's to be expected with a 27/8), but the power curve is very nice and the car is very quick.

Matt Sheppard

Hey Brad

I'm thinking it might also be the stock downpipe/cat robbing you of some spool and power.

What do you think happened on your engine refresh? New rings? Any cyl. prep?

brad-cam

The K27/8 is giving me full boost by about 3500 rpm with 10psi or so by 3100-3200. Not the quickest spooling turbo, but no complaints...

Hey Matt - they mentioned you today at the dyno shop. They don't see many 944's so they remembered you as the last guy to come through with 944 work !

The downpipe may be getting in the way, or maybe just the cat as it's original and who knows what shape it's in. I have a Magnaflow hi-flow cat at a friends place being welded with flanges so I can switch out the cat with a test pipe with the stock down-pipe.

As for the motor, I really don't know what went wrong. I just re-ringed and put it back together. The bores were in excellent shape, at least visually. I did have to force piston #4 into the bore (I got impatient with the ring compressor) and it didn't seem right, but my impatient self just ignored it at the time. I should have taken it back apart. Suspecting maybe a cracked ring, I pulled the head a couple months back to check the bores, expecting a broken ring and trashed bore in #4, but it was perfect like before. Leakdown is terrible on #4 too - my leakdown tool gives erratic results but the result on that cylinder is consistently above 15-20%. I'm suspecting poorly prepared ring lands on the pistons - ie. I may not have cleaned the carbon out of the lands well enough, and maybe on #4, the extra force exerted putting the piston in the bore may have deformed the ring lands, robbing it of a good seal. I just emptied my catch can tonight after several good high speed runs and it had 4-5 ounces of water-oil slurry in it. I don't think that's normal...

All that said, it is running fine, strong (284 rwhp feels real strong) so I'm not too motivated to rip into it...

UK952

I was, with a simple EBC (Greddy profec bspec1) I now have a flat boost curve,
Tony

hosrom_951

With the right tuning, here is what a K27/8@20psi could do:



At 18psi one should be seeing 310-340rwhp with MAF/MAP, wastegate, exhaust and usual 'bolt ons', something isn't right, and i can see why you are dissapointed with the numbers.

jgporsche

284 and 290? I would have thought a lot more power than that. i plan to make more whp than that today @ the dyno. i'm already making more wtq w/ my 26/6.

jimbo1111

Hay Hosrom? Is that a dyno of your car? If memory serves that guy Shane runs a 2.8

jimbo1111

brad-cam's numbers aren't that bad. At 18 psi he would be around 300rwhp. Probably closer to 330 with a fresh motor. What's wrong with that?

brad-cam

Hosrom's chart is reassuring too - it has exactly the same shape as mine, especially with the "knee" at about 3500 rpm.