dr_hunt Posted May 12, 2007 Share Posted May 12, 2007 Nice! Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted May 12, 2007 Share Posted May 12, 2007 Very nice. Well actually it's insane. I tried searching and couldn't find the answer, Aprox. what compression ratio are you running? Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 12, 2007 Author Share Posted May 12, 2007 Very nice. Well actually it's insane. I tried searching and couldn't find the answer, Aprox. what compression ratio are you running? 7.5:1 Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 13, 2007 Author Share Posted May 13, 2007 I uploaded a video to uTube of the session (not as exciting as ZGad's drag race vids, but...) Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted May 13, 2007 Share Posted May 13, 2007 Tim, Congrats Bro!!.. that is awesome! Like scottie said.. the tires will be screaming hehehe. How does she feel on the road? What tranny are you using behind the ole L6? Quote Link to comment Share on other sites More sharing options...
slownrusty Posted May 13, 2007 Share Posted May 13, 2007 Simply incredible! The backfire at the 4 and 5 minute mark scared the bee-jeezus out of me! What were the final numbers? Tim, just so that you know your car has always been an inspiration for me! Congrats! Yasin Quote Link to comment Share on other sites More sharing options...
big-phil Posted May 14, 2007 Share Posted May 14, 2007 What are those backfires from? I have had some of those at 20 psi between shifts? car is an inspiration! 600 whp, now thats what I want. Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 14, 2007 Share Posted May 14, 2007 YOU DA MAN!! That pretty much re-ignited my faith in the ol' straight six. Stroked with N42? I thought N42 has a smaller chamber than P90? How do you get as low as 7.5 CR? What's the reason for using N42 instead of P90? Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 14, 2007 Author Share Posted May 14, 2007 YOU DA MAN!! That pretty much re-ignited my faith in the ol' straight six. Stroked with N42? I thought N42 has a smaller chamber than P90? How do you get as low as 7.5 CR? What's the reason for using N42 instead of P90? The pistons have a BIG dish in them - see below. My N42 has had a fair amount of work done to it, it flows really well, and it works just fine for me so I don't see any reason to change it. (I don't want to start another N42 vs. P90 discussion ). The backfires are from the rev limiter - when it cuts fuel, it dumps a bunch of oxygen into the exhaust, and if there is unburned fuel in there it ignites. Interestingly, at the end of the session, my exhaust was very noticeably quieter than when I started - I think the backfires must have reshaped the insides of the muffler somehow. The effect was there for the last three runs which made the most power, and the datalogs don't show any appreciable difference in turbine inlet pressure, so - bonus! Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted May 14, 2007 Share Posted May 14, 2007 i knew if anyone could make power out of an l28 it was gonna be tim way to go tim, you still live down in dearborn? i cheated and went to the dark side and put in an rb engine Quote Link to comment Share on other sites More sharing options...
PETEW Posted May 14, 2007 Share Posted May 14, 2007 Wow! Those are some very serious #'s I feel like singing a song.....Did you ever know that your my heeeerrrrrroooo! Your everything I wish I could be. OK, I'll stop now. Good job on those HP figures. I wanna hear how she is on the street. Quote Link to comment Share on other sites More sharing options...
TimO Posted May 15, 2007 Share Posted May 15, 2007 Way to go Tim. Huge numbers on street gas. Gotta be a record!!!! Congrats man. Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 15, 2007 Author Share Posted May 15, 2007 Well, I see that the second guessing has begun on zcar.com, so maybe I need to add some additional details... For the first several runs, I was running way richer than I had been when I street tuned - the culprit was later found to be that the manifold air temps were considerably higher on boost than what I was seeing in the real world - like peak temperatures of 132 degF vs. 94degF on the street. This was not being compensated for. My initial target for AFR was 10.5:1 and the car was in fact running down in the 9's for the first several runs. If you do the math this makes sense given the temperature difference. The first run netted "only" ~501rwhp. The reason for the rich target mixture was because of the high exhaust temps that I was seeing with leaner mixtures, as was discussed not long ago in this forum. For the next several runs I was slowly dialing fuel out in order to get back to something sensible, and then after talking it over a bit with the dyno operator (owner of the shop), decided not to worry quite so much about the exhaust temps that I was seeing, and tried leaning out a bit more to see if there was any more power there. There was. The next to last run was the one that I posted, and it was in fact 11.5:1, verified by TWO different, seperately calibrated wideband sensors. There was a spot just after boost hit that went a little rich (~10.6:1), and both widebands correlated very well. The last run was leaner still, running closer to 11.8:1, but still had the same rich spot just after the onset of boost. this run didn't net any more power, and had slightly higher EGTs than the one before it, so I went back to that cal and called it a day. As far as fueling goes, I'm running Ford Motorsports 150lb/hr injectors, derated to a base pressure of 32psi. So, when derated to 32psi, they should be flowing 128lb/hr at that base pressure. My old 72lb/hr injectors went static at around 20psi and 7000rpm. I was running a base pressure of around 50psi on those, btw. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 16, 2007 Share Posted May 16, 2007 awsome Tim! now.. being a 280z owner.. I used to like the bumpers when they were on the car.. but when I removed em I fell in love with the no bumper or 240z bumper look. why are yours still on? Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 16, 2007 Author Share Posted May 16, 2007 awsome Tim! now.. being a 280z owner.. I used to like the bumpers when they were on the car.. but when I removed em I fell in love with the no bumper or 240z bumper look. why are yours still on? Simple - I live in Detroit. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 16, 2007 Share Posted May 16, 2007 I think the backfires must have reshaped the insides of the muffler somehow. I wish my backfires could do that! Quote Link to comment Share on other sites More sharing options...
zguy36 Posted May 16, 2007 Share Posted May 16, 2007 What were your peak EGT's during those runs? I just installed a pyro and am wondering what is considered unsafe. Great numbers by the way. Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 16, 2007 Author Share Posted May 16, 2007 What were your peak EGT's during those runs? I just installed a pyro and am wondering what is considered unsafe. Great numbers by the way. Pretty friggin' high... on the best run, EGTs peaked at ~1750 degF The last run peaked near 1800 degF with 12:1 AFR. I was kind of freaked out by this, but the dyno operator/shop owner assured me that this was common for the Grand National guys, and also on a couple of other high output turbo cars he had tuned, which were all holding together just fine. The car did hold together and put out some good numbers at those temps, although i don't know if I'd want to hold it there for long periods of time... Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted May 16, 2007 Administrators Share Posted May 16, 2007 Tim, Where were the EGT sensors located? Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 16, 2007 Author Share Posted May 16, 2007 Tim, Where were the EGT sensors located? at the turbine inlet, directly in the flow path Quote Link to comment Share on other sites More sharing options...
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