adrial

It's all bore....

Nice numbers Rage.

Do you have the AVCR set to roll into the boost gently or does it naturally build power so smoothly? Maybe a bit too much smoothing?

hosrom_951

JustinL: Only kiding, this is where water injection would be effective right? cooling things down.........

MySwiss

What I can't understand, is why your power is dropping after 5500rpm, with your huge turbo??? I would expect your turbo to still be able to flow above 5500rpm.

Is your boost dropping off after 5000 rpm???

rage2

It just looks like that on the dyno... kinda weird. I think the loading is still a bit off as compared to the street. It hits hard on the street.
Boost isn't dropping. It's the stock cam that does that. Well, that and I haven't touched the timing at all up there... it's running 18 degrees flat timing at 15psi all the way to fuelcut. Some more timing after the boost drop will reduce how much it drops up there, and pick up a bunch more hp.

BTW - it was another scorching day. 35+C on the drag strip. Everyone was running slow, 3 cars blew up from what was most likely heat + detonation. I'm glad I tuned on a hot day.

My SLK ran 13.7@105mph, it's run 13.0@110 at our elevation... gives you an idea of how bad the heat was. The 951 ran a 12.9@110mph in these conditions .

All I have to say is, last year in the 2.5L, after every shift, I wasn't making full boost... narrow powerband which was tough to drive and netted a 12.7@117mph. This year, it's a lot easier to drive. The 12.9 run was done with a soft launch and no power shifting. 110mph trap speed still shows how much less power it's making. The 2.8L's wider powerband makes it that much better, enough to be darn close in trap speed!

Heat soak didn't seem to be too much of a problem, that Thermotec heat wrapping worked real well. The sun on the black hood hurt my temps more than anything... burnt my fingers harsh opening my hood after a 1 hour cooldown from the sun.

I have some video footage, not sure if my buddy caught the 12.9 run, but I know I do have a 13.2@108mph run on video where I bounched a bit on the revlimiter in 2nd. I'll post that shortly.

porshhhh951

sweet

billgot

Rage can you give me some 60 ft times.

rage2

2.18s was the best 60ft time. With the 2.5L motor, best 60ft time was 2.35s.

NZ951

2.35 is a soft launch. I managed that with clutch riding. Didnt want to do the tranny. Next time I am going to nail it regardless, I want a mid 13's.

rage2

yea, that's my strategy too. Clutch replacement is cheaper than tranny replacement!

Claus Groth

Nice runs. It looks like you got the package well sorted.

How did you determine that you had knock? Just by hearing it?

rage2

I have a knock sensor with SDS. I disable that on the dyno, and they have a super secret device (heh) that clamps onto the head and someone listens for knock during the runs. It picks up knock that's not even audible to the human ear. After that, I run it on the street with the knock sensor enabled again which ensures that the settings are safe with different airflow characteristics. I think I have a fairly wide margin of safety, should be able to run a few more psi on the street, but it's capped at 15psi to be safe.

BTW - here's the videos of one of my runs. The only one I got on video. Light puff of smoke was from hitting the rev limiter.

951 1/4 mile - 640x360 (2.5MB)
951 1/4 mile - 1280x720 fast PCs only (21.7MB)
Made about 10 runs, zero oil consumption. Everything's working good!

billgot

Yeah it really does not matter how you launch 60 Ft times will always be around those numbers I had drag radials on my car and got same numbers except for the 2 times I broke an axel.

billgot

Nice video rage quality is great.Shame is that mazda has maybe 100 rwhp and was only a second behind.Your car deserves much better.It just hurts me to see powerful cars suck *** in the 1/4 Mile.

962 kid

good thing thats not a 100 whp mazda

rage2

Mazda? That's a new one .

That was my wife in her 420hp Renntech SLK.