Guest Cronic Posted May 17, 2004 Share Posted May 17, 2004 compression is 7.4:1 on an L28ET I REAAAALLLY doubt you're blowing out the spark, BUT i always run my NGK's at .028" gap. (6 series). Why have you not put this monster on a dyno yet? with 18psi from a 50 trim it should be making a very good amount of power. Well into the mid 300's. It's true when you retard timing you can run more boost safely, but you will NOT be making optimal power. It would make better power to have advanced timing with lower boost. DSM guys use this all the time the less knock you have the more the timing will advance itself and it will make more power. If you're worried about knock, run higher octane, or drop the boost down a couple psi. I def suggest an FPR if you haven't decided on that yet. And perhaps some secondary injectors? Im using 2x450cc injectors with my setup, and running 20psi on stock turbo with a nice happy rich a/f. Quote Link to comment Share on other sites More sharing options...
fl327 Posted May 17, 2004 Share Posted May 17, 2004 maybe give the z31efi system a shot? Quote Link to comment Share on other sites More sharing options...
Jersey Posted May 17, 2004 Author Share Posted May 17, 2004 525 - i couldn't tell you where the line is between retarding timing and increasing boost. I would think you gained a little bit of low-end responce by bumping your initial timing up to 20* but obviously lost a little on top by dropping the boost back a degree or so. 327 - No NITROUS! LOL. I'm not controlled enough to use that laughing gas and either is Nick! Z31EFI is def at the top of the list of possibilities. Cronic - Why do you doubt that stock spark is being blown out by the 50 running 18psi? With the plugs gapped at .042, we were getting mis-fires at high rpm/boost. Pulled the gap back to .038 and all is good. I would be concerned running a .028 gap that your getting a complete/efficient fuel burn. We're basically still working out the bugs on his build we finished about a month ago, and he keeps breaking stuff but, hopefully soon we'll get to the dyno. Shoot, i just want to get to the track! Maybe this Friday. I am going to have to disagree with you on the "retard timing/less power" issue, unless you're talking strictly of losing bottom end power. Retarding timing will make your off the line worse but, the benefit of running that much more boost on top overcomes that bottom end loss. Heck, once you're off the line and out of first, the R's are always up near 4k... who needs bottom end after the first 1/2 second anyway Just my opinion. I'm not sure what you meant when you said that "the less knock you have, the more timing will advance" since i'm not too familair with the DSM ignition systems. I don't run the knock sensors on either of our Z's as well because i just don't know to what degree they retard timing when sensing knock so, i just let it advance as much as wants too and keep my ears open Aren't we all worried about knock when running the L28ET to the limits of it's current build? We run 93 pump gas and keep the boost level as high as possible without ping. I also think the next purchase for his should be an FPR. It'll keep him safer on top end where i think he's leaning but the down side is that he'll be a bunch rich low to mid. 20 PSI on the stock T3??? Wow, i thought i was majorly exceeding the T3 by running 17psi! haha. I do like the sound of an extra injector or two and possibly have them activate by way of a pressure switch I just haven't really found a bunch of information on doing it. If you want to share some pics/info or your additional injectors, that would be appreciated. Thanks for all the replies and info. Quote Link to comment Share on other sites More sharing options...
fl327 Posted May 17, 2004 Share Posted May 17, 2004 you can get the pressure switches from napa auto parts, or a diesel supply company may have them. They are called hobbs switches, and I used to have pn#s for them. Napa calls em pressure switches, same difference I guess, they are cool they come in different switch on vac/boost non adjustable. I will look for the numbers and let you be the guinea pig for them! I want to run a 25 or so nitro shot, just so that I can claim TurboNitrous! Quote Link to comment Share on other sites More sharing options...
yo2001 Posted May 17, 2004 Share Posted May 17, 2004 18psi and .040"+ you can blow out the sparks. I have to gap mine down to .028" for anything over 23 psi Quote Link to comment Share on other sites More sharing options...
Jersey Posted May 18, 2004 Author Share Posted May 18, 2004 Oh sure 327, make me the guinea pig! ha. My buddy works for Detroit Diesel so i'm sure he can get some pressure switches. As a matter of fact, he's the one that put the thought in my head months ago! On Nicks Z, he's using the '75 (?) non EGR intake which had the cold start injector right after the throttle body, which we since removed and plated off. I wonder if we can use that as a supplementory "high boost" injector, activated by a hobbs? That would real easy to do and i think directly after the throttle body would be a good place to distribute fuel across the cylinders. Someone else has had to have to try this, hope they chime in. Guess i'll have to do my homework on what that cold start would spray with 40-50psi of fuel behind it. Yo - are you running them down to .028 with stock Z31 ignition? I was concerned about bringing them back to .038 when i did but if you think you're getting a complete burn down that low, then i guess i can cut him back a little more. Thanks guys. Quote Link to comment Share on other sites More sharing options...
fl327 Posted May 18, 2004 Share Posted May 18, 2004 cold start injector isnt the optimum place to put an injector, but it could be a place to put ANOTHER injector, once you have one or two in the intercooler piping. I was thinking of running a couple in the injector piping man it just sounds cool. The cold start injector isnt a regular sized injector stock, its a funny little guy that probably doesnt flow any flow, its kind of a dropper to stabalize idle. I would go to a junkyard and grab some RX7 injectors or something and let the rubber fly, bet you its fun. May not be the most efficient way to make power, but hey whatever. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted May 18, 2004 Share Posted May 18, 2004 It's true when you retard timing you can run more boost safely' date=' but you will NOT be making optimal power. It would make better power to have advanced timing with lower boost. DSM guys use this all the time the less knock you have the more the timing will advance itself and it will make more power. [/quote'] okay cool for a while I was starting to think I was the only person who thought this. You guys know me... at some point the question will bug me enough that I'll go down to the dyno and plunk down $100+ just to know for SURE what the case is.... I'm betting I can get more power with more timing and less boost... need to get my adj. FPR so I can up fuel pressure and get a constant air/fuel ratio... make it a fair test ... give me a few months and I'll know for sure. Quote Link to comment Share on other sites More sharing options...
Jersey Posted May 21, 2004 Author Share Posted May 21, 2004 Thanks for the info 327. I'll need to look at where others have placed their addl injector(s). I didn't know that before the TB would be better off then after. I guess better atomization and distribution? I also cant understand why this wouldn;t cause more chance of detonation since there be a good mix of A/F in the intake? Have my homework to do. Anyway, picked up 2 MSD-2222 adjustble FPR's today, one for Nick and one for me (i dont really need it probably with my little T3, but i dont want to fall too far behind ) and installed them both tonight. He was running 32lb of fuel @ idle and nearing ping @ 18# boost. We cranked the MSD to about 40lbs @ idle and can now stretch the T3/T4 up to about 21lb. I think we're going to make a run for the track if the weather hold out tomorrow (friday) night. Maybe slap a liitle 104 octane in there and see how she runs. It's gonna be a shame when he sees my tail lights when crossing the trap Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted May 23, 2004 Share Posted May 23, 2004 wow... I wouldn't have expected such a meager increase in fuel pressure to compensate so much and allow a whopping 3psi more boost!!! It's so odd in some cases it seems like similiar fuel pressure increases have no effect... and sometimes it seems to make all the difference in the world. I remember on my N/A ZX with stock EFI, pushing 10.3:1 compression, it would ping like crazy at WOT above 4500rpm... bumped fuel pressure up TWO PSI, bumped timing down two degrees, and I could take it to 6500 all day long with no problems. On my turbo motor... adding 3psi of fuel pressure didn't seem to make any difference at all (maybe this suggest somethings wrong??), in driveability or on the dyno.... whereas adjusting the AFM spring tension by as little as two teeth on the gear seems to make a HUGE difference... any more than three teeth either richer or leaner and the car runs like super crap. Quote Link to comment Share on other sites More sharing options...
Jersey Posted May 23, 2004 Author Share Posted May 23, 2004 Best run i had this past friday was my best by .022 and 1 mph I ran a 12.866 @ 112.14mph. No traction AGAIN. 60ft was a horrible 2.11. Humid as heck too @ 95-100%. Nick and I ran side by side a few times, but just could not hook off the line. Actually, nobody could. We did get one run in side by side that was fun as heck - My 13.236 @ 111.45 to his 13.291 @ 113.81. Neck and neck the entire way down the track! .055 difference. Video to be posted soon. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted May 24, 2004 Share Posted May 24, 2004 time for some real tires. Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted May 24, 2004 Share Posted May 24, 2004 Thats awsome Len.. and yeah.. need tires now.. Do you have a LSD?? if not.. WOW.. I suggest one.. I put mine in on friday.. WHOLY COW.. it is a whole new car!!!.. At anyrate.. Awsome times and I cannot wait for the vid.. Quote Link to comment Share on other sites More sharing options...
Jersey Posted May 24, 2004 Author Share Posted May 24, 2004 Thanks. You're not kidding with the tires. Last time i went, i promised i wouldn't go back without real tires... broke my promise and suffered! lol. I mainly went to see how my cousins 280 is running, which turns out good. Think i'm going to look into the Hoosier QTP's - 26" for both of us. The tires i ran at the track were 25" and @ 112mph, i was crossing the trap near 61-6200 rpm. T5 w/3.54's. Think i'd like to be down near 5500 and hoping the 26" will do it. NO LSD but we didn't have a problem with the one wheel peel. Always hooked both tires... well, spun both tires i guess. lol. I'll post vids soon on a new topic. Thanks again guys. Quote Link to comment Share on other sites More sharing options...
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