Speedtoys

Is this..really your form of entertainment on a weekend, and others actually out doing so (on topic as well) have to pay a penalty when you and yours dont like -a- thread?


I paid my $32, and it wasnt...to you. I dont need your acceptance, I aint hangin on it to get by.


Im not sayin, just sayin.



That's all I've got to say about it, I sincerely hope that future threads that anyone else may post, that keeps you from your weekend...meet a softer fate.


928 content:

I went out and beat the crap outta mine today...loved it, and didnt **** on anyone else's personal achievement while doing it.

Congrats to an up and coming racer..payin his dues..and in his mind, finding the pair to make a challenging corner comfortable.

justaguy

Jim congrats on winning our silly game. easy for an offshore sailor. Actually it's turn 8 not 10 but you win any way. This was a follow up to a previous thread about max speed thru turn 8 at T-hill. I carried more speed on other laps I think 95mph was the Max-----Min speed at the apex but pulled less G's around 1.95 which means I was faster but the car was loosing grip or drifting through 8. In any event with the traquemate data I have found the maximum miniumn speed thru turn 8 in my car.
Which blew up shortly after that lap, but thats a whole other thread

White Lightnin'

Just following the logical progression of posts... and apparently I'm not the only one that likes 928 content in the 928 forum.

One of the Mods will be moving this to Off Topic soon enough.

BTW, you (and most of us here) are of a true minority of those that appreciate the 928. Even within the walls of Porsche, the 928 was and is the 'red-headed stepchild' of Porsche... unloved, unwanted, unappreciated by most.

To be in such a minority -most of us have developed a thick skin... it may benefit you to do the same.

fraggle

Relax guys I thought it was funny.

jcorenman

I was counting in Octal

And the prompt, of course, was for PICTURES!! Seriously, 2.0G through turn 8?? Holy grip! Holy Cajones!! Where's the video?

So Sean, what happened to the car? Did I miss a thread?

[As for 928 content, that wasn't some son-of-a-veedub that Mr. Finn was driving... ]

928mac

When you zoom in, isn't that sean with a hot dog in his mouth. LOL

White Lightnin'

Pics... or it didn't happen!

mark kibort

If 2g's is the story, you are right, it didn happen!
Based on the distances and arcs of turn 8, 95mph would work out to about 1.2-1.3gs

They must be using the same g meter that Jeff used to tracked his speed through turn 8 at 115mph in the Rx8 street car

mark kibort

Sorry to hear about the car! What a huge BUMMER!!
any idea what could have caused detonation in the one hole, and others were not effected? bad injector?

justaguy

Ok here's what I know.
The 2 gs came from the traqumate data never made it up or geussed at it and no one said it was sustained just the highest recorded number. There were lots of 1.95s recorded at the same location but 2 was max. I was quite surprised by the number myself 1.4 seems to be max G that I can hold for any amt of time. I will post the data as soon as I figure out how. I will post what video I have as well just to up the 928 content. I think my best lap was a 2:07 I had an NCRC transponder in the car so results should be posted on their site or where ever they post them.

The car blew engine # 4 yesterday. We looked down the spark plug hole on cylinder #8 using Kevin Murry's bore scope gauge. Looked like the top came of the piston it appeared to be split through the wrist pin hole but was hard to see. Wrist pin was still there and connecting rod was still there. I have no ideas what happened Car was running strong with good temp and oil pressure and AFR there was no indication of a problem faliure was sudden just shifted into 4th gear on the front straight and KaBoom! Big Smoke Cloud. May have dropped a valve but who knows I will know more when I get it back home and opened up. I will up date when I know something.

Brad, not a hot dog fan by the way. Why don't you stop by my shop the next time your in Edmonton my shop is in Nisku by the airport if you've got nothing to do you can give me a hand to assemble one of the three motors I have in pieces.

Sean

mark kibort

I belive you that you have the data, but the physics doesnt support it, so I would suspect that the data might be skewed by something. I dont even kow if an instantaneous G can be suppored if the sampling rate was slow and you got lucky and picked up some noise. 95mph with your car seems to be about right, and Im sure you could hit 100 if you pushed it, which Im sure you know. (or maybe after we set up the suspension next time I see you )

Wish I could have made it out to see you and the gang. Sorry to hear about it. more work. But, short blocks are cheap and there might be things savagable, or like you said, just bolt in another one

One thing I was going to mention, is really analyse the piston top. if things were melted, thats detonation and that could be the fault of a bum injector. you should be running near 55-60psi with the 24 lb injector ( i supported 320rwhp with 71psi with stock injectors) so, you probably were close with mixture overall, but you never know what each cylinder is doing unless you have EGT sensors. how to fix imbalance is anyones guess. probably a problem with the injector or a real bad air leak, but that should be very obvious.

I would bet you dropped a valve, especialy since you have a little hopped up cam and valve springs can break and so can retaining clips.

IcemanG17

your engine was quite a surprise....the 1st I have ever heard of that type of failure...just flat odd....

Still it was a successful weekend..... two GT3 class wins....two GT3 2nd place finishes and an overall WIN.....not to mention the time trial win too....

In other words...928's rock....

justaguy

yes a suprise and a real drag. It was running awesomely but as every body knows they run best just befor they blow

mark kibort

just so strange that the plug was all mashed up, and that there was a hole in the piston. do you have a picture of the plug? if you dropped a valve, certainly the parts could punch a hole in that incredibly strong piston face! it would take a lot, but it could be done. heat is usually easier to make holes with, so, detonation certainly could be it. BUT, why only one cylinder with all others looking fine and a 13:1 AFR ratio just shown on a dyno that weekend?

another problem with dynos, and their AFR sensors, as I have found , is that the tail pipe reading can be skewed and have a some delay in it. better to screw a wide band into the O2 sensor and take the reading there. just unplug the 02 sensor from the system in the fuse panel (dont worry, i did a dyno run with and without the 02 sensor connected, nothing changed as its open loop WOT.)

If you are 13.5:1 AFR, that means its an average of only half the motor. each cylinder can be off a bit. 13:1 for one, and 14 for another. If near 14, you could be near stoich, and that could give detonation, but in our motor where it is under utilized, that is unlikely. I still am thinking either a problem injector, or a dropped valve.

was it still running when you came into the pits or did you just park it and get towed in?

UGLY!! sorry to hear.

Dont worry, you will be back in no time!

Mark

IcemanG17

the more I think about it....I am thinking it sucked a valve, which caused all the destruction....all of the other plugs had no indication of being lean...... So that is my theory