mark kibort

going to do some basic tests to see where the ole car is at.
one of the tests, will be a run, right after the power is removed from the battery to see the effects on power on a "non adapted" computer.
just cleaned my K/N with the solution in the cleaning kit, but used no oil this time.

mk

Thaddeus

I'll be interested to see the results!

heinrich

About freakin' time

mark kibort

I think the car has been feeling a little soft, ever since we slipped the teeth and re timed the car. I retimed it again with a new belt soon after, and then it felt faster, but we all know how inaccurate the butt dyno is! anyway, before the slipped tooth, we dynoed the car at 316 to 320hp with the dual throttle body from Tom. the gains were only 3-5hp peak, with some interesting gains in the midrange. anyway, i also wanted to calabrate the Mustang dyno with the dynojet.

so, the car has been pretty consistant on my runs from 60 to 100mph at 5.8 to 6 seconds, down from its best of 5.7 seconds when it was at 335 hp and 335ftlbs at the rears. where those 15ftlbs went,i dont know. the compression is still the same and the mixture is still in range to i imagine.

we will find out in about 2 hours!

part of me thinks by making the timing correct on the passenger side, i changed something going the wrong way hP wise. the marks never really lined up perfectly, so now, its closer to the mark , but on the other side of that straddled tooth.

MK

mark kibort

Good news, the engine is in good shape still. 323hp (thats actual not SAE on a 80degree 29.90 pressure day) SAE HP was 322.
Bad news, flappy dont seem to be working. connected, vacuum connected. Hope its not a computer connection or issue.

ive attached the dyno run 2 years and 2 full race seasons ago. (pretty close, except flappy was working)

Interesting for those of you that wonder how long it takes for the computer to adapt, the two runs are about 4 min apart, earlier run was pretty hot. (water at the white line, as the dyno guy turned off the big fan without telling me. ) next, i pulled the battery positive, and then reconnected after a min. and did a run. NO real hp diff, and mixture seems to be close too. (a little leaner after the reset) im still wondering about the adaptation part of the computers. effectively, sure doesnt seem to be much of any.

Mark

heinrich

HO-LY SHE-ITE Batman .....

Tony

Strong old bird!
IMHO..You definitley have some factory voodoo going on in that motor somehwere.
S4s dont put those numbers to the wheels on a regular if AT ALL basis!..
thanks for posting them!

Thaddeus

Yes, there's something going on there.... you don't think Porsche cooked the books on the original record land speed run, do you?

Nahhhhhhhhhh...

John Veninger

Why don't you post an the SAE graph like everyone else does?

Scott M.

Nice numbers Mark.

Can you scan in the corrected numbers?

My basically stock 89GT w/ rmb and 120k miles did 309 rwhp/307 rwtq, corrected... so yours is interesting to say the least.

Scott

Bill Ball

"Yes, there's something going on there.... you don't think Porsche cooked the books on the original record land speed run, do you?"

Mark has done some external mods, to which the car responded rather well, so this isn't exactly as Holbert drove it. It may have been a bit hotter than your average 5-speed S4, but I did just over 165 in my unmodified AT at a higher altitude than Holbert's record run. 171 is attainable by a 5-speed S4.

pewter82

Hobert car is now supercharged? it says 86 928 electricsupercharger on the dyno....

and how does Scotts 326HP GT put down 309 RWHP? I've been told a 346HP GTS will put down in the high 280's to the 290's RWHP I can't imagine that Porsche engines have such a variance in the actual power.

jason

Scott M.

Jason;

I goofed, it is 307 hp and 309 tq. That was on a mobil Dynojet 248C. The 89GT ran a 303 rwhp/310rwtq on Autothoritys Superflow, a 303/301 on a Dynocom, and many 300+ runs on various G-techs.

mark kibort

I dont think its too far off, as my 85 bottomend 5 liter was mated to euro intake and euro 2 valve heads, and was breathing through a 2"x1.75" AFM flappy door and put down 293 hp at the wheels. (and not even the hottest of the euro cams, only the 1982) if that 5 liter bottom can make 293hp, i would think with 4 valves and a 3.5" diameter MAF, that 25 to 35hp could be lurking.
certainly, the GT style cams (or probably better said, the 1985 cams fit for the S4 prototype, equal in lift and close to duration to the Later to be seen, S4) would put down the extra power as well. We havent seen whats in side yet, but we have seen the cams. it is a strong old bird, no doubt. I just get a kick telling folks this car hasnt had a bolt turned on its engine since it was put together in 1986!!! (i forget to tell them, the car only has 30K orignial miles)

I think the remarkable thing about the Holbert car is 4 racing seasons, and still kicking, not the 10-15hp over some of the other 928GTs out there.

mk

mark kibort

so, the flappy works when vaccum is present to its feeding tube. However, i have no vacuum to the solinoid. So, there is the problem. went to the vacuum source and found that there is a little one way valve that allows the vacuum booster to fill the vacuum storage canister, and that runs the flappy. the little valve seem to be allowing vacuum , but not enough to meter at the Y where the main vacuum line out of the little valve, meets the vacuum canister and flappy solinoid lines. took the valve, rinsed it with brake cleaner and it seems to be better now. i can hear vacuum when i pull it off the canister or the flappy solinoid. now, have to see if the computer is telling the solinoid to do its thing.
tommorow ill make some noise.

definitely a reason for some lack of speed and time at the track. thats 800rpm where im down about 25 to 30 ftlbs of torque (ie 4000rpm to 4800rpm)
its one of the reasons that my 60-100 runs have been slightly slower, particularly from 60-80mph. Now i think i know why

MK