mark kibort

They are the stock plugs, and the old ones from the holbert car. New plugs coming slightly colder.

remember, during cruise, and part throttle, the 02 sensor is trying to keep mixtures in the 14.7:1 stoich range. dangerous for higher throttle settings, but perfectly fine for cruise. The true test will be after some full throttle runs after the motor is ready for it. My in car 02 AFR meter is regestering 12.5 and richer during the quick WOTs I have done. It will be interesting to see how accurate it is. Before i do too many of those, i want to make sure the mixture is right. no pinging right now either.

mk

mark kibort

any predictions for power?

Im guessing something north of 400rwhp.

90 S-4

367rwhp

mark kibort

Well, i can tell you pretty easily, that thats going to be pretty far off.
put it this way, when going from my 285rwhp to the 335rwhp Holbert car, that 50hp gave me a 5.7 second 60-100mph time, coming down from near 7 seconds. This engine is gaining 1 second just in the 60-100mph range.

We will see.

90 S-4

What I was thinking and should have said, is 367 on a strict dyno & 408 on the more commonly
used type of dyno. Either way it sounds like it picked up a bunch ! & great job on getting done !!

stolarzj

So I just took my car in to have the TBelt tensioned since I don't feel like dealing with it right now and the scary light came on. I took it to Rennsport here in Charleston run by Stan Turner an old time mechanic for race teams and worked for PCNA for a time. We got to talking about 928's and he mentioned that when he worked for PCNA one of his projects was to work on the Holbert car used for the speed run. He said Porsche had him swap in a Euro transmission, they apparently wanted to show the car running right to the red line for the commercial, I should have asked if it was in there for the speed run also. After they were all done with the car he then swapped back in the normal transmission it came with.

If you want to talk with him about the car, I could get you his number at the shop he may have some other interesting stories about the car.

mark kibort

That would be very interesting. I also talked to some of the team on the speed run. they said they ended up using the stock 2.2 transmission after all, due to wheel spin.

mk

mark kibort

whats a strict dyno and what is a common dyno. the holber car ran near the same numbers on both very close apart. 318 on the mustang dyno and 320 on the dynojet. its first dyno run 7 years ago was 335rwhp on a dyno jet, it later fell in the mid 320s for years.

mk

stolarzj

They may have just used it for the commercial, apparently Porsche really wanted to show it going to the red line in the commerical.

mark kibort

Ok folks, more time driving around. it runs great, but for some reason, now it wont idle. (hunting real bad and it will die) anyone know what could cause this?

the good news is that its running real strong other than idle, and i did some more freeway runs. this is going to be the longest 500mile wait of my life! Some folks that know motors are saying, go to the dyno now. any thoughts on that? just a couple of pulls to see where the AF is, what do you all think?

I could change out the cheapo oil and put in the amsoil and go for it. The current oil is very clean. I'm thinking of using it in my BMW when Im done! (kidding)

Anderson and Fan put their engines together, run for a few heat cycles, go to the dyno and its off to the races!

By the way, I did roll into a 3rd gear run to 100mph. (about 5800rpm). .................drum rolll...........
1.9 seconds 60-80 and 2.3 80-100mph. 4.3 seconds!! (holbert engine pulled the car in 5.7 on its very best days, and recently in the 6.2 seond range. Its a monster!

Its got 75 miles on the motor now!

mk

Bill Ball

Did you tighten up the O2 sensor you said was "hand-tight"? How about the vacuum lines?

Hilton

Few likely things for hunting idle issue:

Throttle sensor idle microswitch not working
Idle Stabiliser valve not working
Temp II sensor failed (continuity issue on either pin when put to ground)

Temp II is easiest to check as the others are a bitch to get to

slate blue

There was a discussion on the Landshark list about a year ago about the amount of losses there is in the driveline. There is also a discussion about this topic on 928racing.com Apparently there is a lot of losses in the tyres. I always thought and this is based on what I had read on this board that the losses were about 22% for the manual and 25% for the autos. The Porsche club here uses a factor of 1.32 to obtain your flywheel figure from the rear wheel figure to classify what class you compete in.

I think what 90S4 is referring to is that there is a large difference in dyno figures with the dynojet traditionally having high numbers, Dynopak and Dyno Dynamics are two dynos that give much lower figures. Dyno Dynamics gives the lowest as it factors in the losses from the tyres whereas the Dynapak bolts to the hubs. If you want to get an idea, google dyno dynamics and put the word heart breaker in there

The DD dyno also has a shootout mode that has tamper proof features such as a controlled rap rate that gives consistancy between operators. The member who gave an estimate on trans losses is also on this board but I will let him post his info if he wishes.

Greg


[QUOTE]whats a strict dyno and what is a common dyno. the holber car ran near the same numbers on both very close apart. 318 on the mustang dyno and 320 on the dynojet. its first dyno run 7 years ago was 335rwhp on a dyno jet, it later fell in the mid 320s for years.

mk/QUOTE]

mark kibort

vacuum lines working . fixed that one leak, but you know i purposly had the leak to raise fuel pressure at idle. It made no differene. Ill have it hooked up when we get together.

YES, the O2 sensor was real loose. about 1 full turn. I bet that was it. what do you think?

So, what do you think about a dyno this week. dyno it with the cheapo oil in it? Bill, you want to do it this week?
Ill put another 50 miles on it today. I hope that o2 sensor fixes the issue.

mk

mark kibort

Nah, I hang around a lot of racers and there hasnt been that much differene between dynopack and dynojet. again, personally, I saw near the same HP on the dynopac brake dyno vs my runs over 7 years on the dynojet chassis dyno. H

Rollling friction, I tested this a long time ago. 20hp loss at 150mph and 10hp loss near 80mph (4th gear dyno run) I have this documented. the rest of the losses are in the gear box. generally, its 15% for manual and 20 for autos but thats real general and more of an average. Probably good to use at peak HP values.

mk

[QUOTE=Greg Gray;5717558]There was a discussion on the Landshark list about a year ago about the amount of losses there is in the driveline. There is also a discussion about this topic on 928racing.com Apparently there is a lot of losses in the tyres. I always thought and this is based on what I had read on this board that the losses were about 22% for the manual and 25% for the autos. The Porsche club here uses a factor of 1.32 to obtain your flywheel figure from the rear wheel figure to classify what class you compete in.

I think what 90S4 is referring to is that there is a large difference in dyno figures with the dynojet traditionally having high numbers, Dynopak and Dyno Dynamics are two dynos that give much lower figures. Dyno Dynamics gives the lowest as it factors in the losses from the tyres whereas the Dynapak bolts to the hubs. If you want to get an idea, google dyno dynamics and put the word heart breaker in there

The DD dyno also has a shootout mode that has tamper proof features such as a controlled rap rate that gives consistancy between operators. The member who gave an estimate on trans losses is also on this board but I will let him post his info if he wishes.

Greg