Thumper Posted October 20, 2004 Share Posted October 20, 2004 Well I'm going to dyno this thing friday and then run it at the track. I looking for 200hp and 220lb. And at the track I would like a trap speed of 100 and hopefully a 13.99 in time. First my specs. 83' 280zx turbo 5-spd 1g BOV, MSD 6al, MSD Blaster 2, Magnecor Wires, 60mm tb, Custom Intake, Adjustable FPR, MBC set at 10psi, and a 3 inch non-mandrel exhaust. I have also completely stripped the car. It should weight about 2600 without me in it. I weight roughly 150. I have brand new 225/60 bfgoodrich g-force sports on the stock 15x6 turbo wheel. I think I am going to try to keep the air/fuel below 12.5:1 and above 11:1. I can adjust the fpr, the spring in the wheel of the afm, and the actuall arm position in the afm. My timing right now is set at 27deg and I have no problem with pinging. So far on my kill board includes a stock 350z by 5 car links, a intake and exhaust mustang gt by 3 car links, and 4wd gsx who says he runs 13.7 buy a nose. (all with very old 205/60 Cooper Cobra tires). Does this sound about right or what would you change. TIA Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted October 20, 2004 Share Posted October 20, 2004 With that same set up accept the FMU.. I ran a 13.8 @100mph in my 77. As long as you get a decent 60ft I would think you can do it. Good luck. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted October 21, 2004 Share Posted October 21, 2004 Your HP numbers should be right around what you estimate... I'd guess about 210hp to the wheels. However, I say go pony up $10 and get your car weighed on a truck scale, so you really know what's going on there. I'm not sure how 'stripped' it is, but getting an '83 ZX down to 2600lbs would be quite a feat. My '72 240 Z, when it was stripped, which is to say, basically was minus interior (carpet and trim, all it had were two seats and the dash), no spare/jack, tools, and like 5 gallons of gas, weighed around 2270lbs. After installing new carpet, floor mats, spare, tools and jack in the car, approx same amount of fuel, weight crept up to 2320lbs. Stripping didn't really make a huge difference... so I'm wondering how you're accounting for ~300-400lbs stripped from your ZX. Either way, running 13.9 or faster should be no problem if you can launch it well. Quote Link to comment Share on other sites More sharing options...
Thumper Posted October 22, 2004 Author Share Posted October 22, 2004 Thanks for info. At the track there is weigh station right after the ticket booth. I believe its fairly accurate so when I go the track i'll be able to weigh my self. I have just about removed everything you can to remove yet keeping it safe enough to drive there and back, well atleast kindof safe. Hey bastaad525 I know you have done alot of reading on the air/fuel ratio. Was wondering what you run and what you would recommend. Right now my settings are 42 psi with the fpr unplugged, 29 degrees timing on a 83 ecu, BPR7ES-11 set at .045, 10 psi with a mbc, and no pinging at all. I am shooting for under 13:1 and above 11:1. I can't wait intill I can get this into my other z and get an intecooler. 12 psi here I come. TIA Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted October 23, 2004 Share Posted October 23, 2004 Heheh oh no you don't want to get me started about a/f ratios !!! Ah... um... I'll try to keep it short?? (is that possible for me to do? ). My setup - I run an FMU, which only affects fuel pressure when there is boost in the manifold, so my off-boost fuel pressure is stock (32psi at idle/20hg's vacuum, 40psi at idle with vacuum reference hose disconnected). At full boost/WOT I'm running about 60-65psi of fuel pressure. Unfortunately... this creates a pretty up-and-down fuel curve, with mixture running super rich from 3000-4000rpm, just right from 4000-5000rpm, and too lean after 5000rpm. This isn't all the FMU's fault, as the first time I dynoed my car, w/o the FMU or my I/C, running 10psi on stock everything, I saw the exact same fuel curve. I've seen other stock or mostly stock ZXT setups dynoed (talking '81-83 of course), and all showed the same pattern. Your a/f ratio is also probably pretty much the same. That is to say, if you're setup is running as a 'typical' stock setup, you should be at about 10:1 a/f from when boost hits up (unfortunately there doesn't seem to be a way to get rid of this super rich dip as long as you're running stock EFI) until about 4000rpm, then up to about low/mid 12:1 up to 5000rpm, then low 13:1 and it will slowly but steadily lean out from 5000rpm on up. It's worth noting that as a rule, I never revved any higher than 5500rpm... not only for safety but also because after that poing power drops off steadily and rapidly. I'm running what most people would consider to be 'risky' lean right now. The 4000-5000rpm part of my fuel curve is in the mid 12:1 area, and above 5000rpm it's into low 13's. Unfortunately still also running super rich from 3000-4000. I ran w/o an intercooler or FMU at 10psi for about a year, and had almost exactly the same a/f numbers, and never pinged. And there are many other guys who've done 10psi on stock everything, presumably running the same a/f ratios. Whether they were daily driven, at the track every week, or whatever. I've been on the dyno several times, and never a ping, audible or otherwise (pinging should show up on the dyno graph as the power line would suddenly get very erratic). And now, same deal after I installed the I/C and FMU... actually before the FMU, I upped boost to 12psi with the I/C, and dynoed and was running even leaner, 14:1 area, and no sign of ping. I've heard or read of other guys running similiar setups, running lean like this, and never having a problem... many, just like me, ran it that way for long periods of time w/o knowing they were lean until finally getting on a dyno, but never had any problems from it. There are guys on here now who either know they are running lean, or ar pretty sure of it, but have no problems. It's my 'theory' that the L28ET is much more ping resistant (that is to say, it's harder to get it to ping, not just that it can withstand it better) and can get away with running leaner than most people would consider safe and be fine.... there's just too many guys out there running that way with no problems. I originally tuned it much richer on the dyno, but saw a pretty significant loss of power on my graph's from this. Other setup info... I run BPR6EY-11's, gapped at .050", running an MSD 6A. I have timing advanced 2* from stock (22* BTDC at idle). Well... I tried to keep it short the bottom line really is it's up to you to decide how much risk to take. There is a lot of evidence that you can run leaner than what is considered 'safe' on these motors, or even more advanced timing, and get away with it forever, AND make more power for it. But... it's still a risk. I wouldn't ever say... "hey I'm doing it so you should do it too"... I'm just sharing what I've learned. I guess it really boils down to "if it breaks, how much is it going to hurt you?". I would recommend what everyone else here would recommend... run rich and safe. 12:1 at the leanest, seems to be the common oppinion of 'safe' For me... well, now that I have a second car I'm not as worried as I used to be... and I've had enough 'practice' fixing it that I don't worry that it's too big a job for me any more, so don't mind taking the risk and reaping the reward. Another big factor is how you drive your car. I only drive mine once or twice a week, to and from work, on crowded SoCal streets and freeways. I don't (really, CAN'T) ever just get on it WOT and hold it for a 'long' period of time... just really ever get to do short spurts really... if I ever did get on it like that, I probably would break or melt something. I also think I should mention... it's rather odd just how much power I lost when I richened up the fuel curve... from 20-40ft lbs of torque over the midrange power band. Yet, I've seen others dyno while tuning a/f ratios, and only gain (or lose) a few ft lbs or hp, from very similiar changes in a/f ratio. So there might be something else going on with my setup, and I couldn't say "yeah you're gonna gain THIS much power if you lean it out a bit" you might gain very little, not even enough to notice. I recently had a conversation with a guy who used to post here, under the name BLKMGK, who's taking classes (or attending seminars I forget) on the tuning of EFI, and really seems to know his stuff. He suggests that mixture really is secondary to making power, either way you go, and really running rich is just to keep combustion temps cooler, and that timing is the REAL key to finding free hp. I would say, as it is right now, you're probably fine with your setup, barring any 'marathon' boosting like I was talking about. Even for shots down the 1/4 mile, you should be fine (how many others have gotten away with it?). Once you get the I/C in and up boost, if everything else is the same you will be running pretty lean. If just using the FPR... you want to try to at least get your WOT/full boost fuel pressure up to ~60-65 psi. You can up base fuel pressure at idle, then adjust the afm spring a bit tighter to lean out the low/mid range and keep your car from driving like crap off boost. Well.. hope all that helps... at least gave your eyes a workout eh? Quote Link to comment Share on other sites More sharing options...
Thumper Posted October 23, 2004 Author Share Posted October 23, 2004 Thanks for info bastaad525. Unfortantely I could not go to the dyno yesterday. Maybe in the future I will. I was able to go to the track last night and it was fun. My car did weigh 2535 with out me in it and 2685 with me and my helmet in it. I still have half of dash in there, a passenger side seat, some tools, and other little stuff I can remove if I feel like it. My main problem was with my 60'. I could not get them to stay very consistent. My problem is I have very blown shocks, and a broken rear diff mount. So either bog or spin. Although I did not try to slip the clutch because I am not sure what type of clutch is in it and I did not want to worry about it overheating. Well my fastest was 60' 2.056 330 5.721 1/8 8.722 MPH 81.36 1000 11.383 1/4 13.603 MPH 101.20 That was at 10.5 boost and a small spike of 11psi. Fuel pressure was at 35psi with vacuum or with the line attached to the manifold should be about 43 psi unattached. And timing is at an unknown setting I will go see where I had to move it last night after it stops raining. Most of my runs where in the 13.7's with a 60' of a 2.1's. I think with better suspension and rear diff mount I could have gotten into the 13.5's. I can't wait for two weeks the temperature should drop about 20 degrees. Can't wait to get this motor in my other car Quote Link to comment Share on other sites More sharing options...
Mikelly Posted October 23, 2004 Share Posted October 23, 2004 That weight is way to light for an 83ZX.. Something has GOT to be up with that scale. This car has the stock body work, Glass, and factory bumpers??? Those are very respectable times though, and if you cang et that 60ft. time down a bit, you will have yourself a 13.5 second car, no doubt! Good Job! Mike 8) Quote Link to comment Share on other sites More sharing options...
Thumper Posted October 23, 2004 Author Share Posted October 23, 2004 Thanks Mike. Yeah i was thinking at lowest 2650. I did weigh it a couple of times as the night went on and it did loose about 15lbs as the night went on because of less gas. I was at houston raceway park and there was a few dodge neon srt-4's there I was hanging with. They weighed 3150 and 3095. They had sunroof's and aftermarket exhaust other than that stock. And from what I know that is right where they are suppose to weigh. I have stripped all the a/c, heating, and blowing stuff. Remove half of the dash by cutting it. No radio and speakers etc... No carpet or any panels at all. I cut the hood alittle bit for better cooling and to get rid of some rust. Removed the middle part of the front fascia cause it was bent badly. I was at a 1/4 of a tank of gas. The car does have full exhaust, stock body panels, stock glass, factory bumpers, pass side seat, some sound deading, heat blanket on firewall, stock electrical dash, power steering, power windows, power mirrors, and rear sway bars. So do you guys think wrong scale or just light weight car Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted October 24, 2004 Share Posted October 24, 2004 Thumper, not sure if you'll remember me but, we met at Ennis last year when you had the valve train issue. I have the red ZX. The scale was wrong.. No question about it. Mine weighs 3100 and if I'm not mistaken is the same as your car. The 17's and adapters do add on some weight to mine but, not that much. Nice times though Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted October 24, 2004 Share Posted October 24, 2004 i cant see how it was wrong, as i weighed my Z in on that scale and on another and both were within 5lbs of each other. thumpers car is pretty stripped!!!! ill say that. great times man. mike Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted October 24, 2004 Share Posted October 24, 2004 well... that's odd if they are weighing other cars there (the SRT-4's) and they seem to be coming up with the right numbers. I too am pretty shocked to see such a low weight for his ZX, but given his estimated hp (~200rwhp) the weight also jives with his 1/4 mile times. Surely lots of other guys would have noticed if it was off and would be spreading the word. Maybe his ZX is WAY stripped? Sounds like he removed a LOT of stuff... but yeah ... 2500 is pretty light for a ZX. I say still take it to a truck scale or a scale at an equipment rental place. If I remember right, the guy there told me that by law they have to have theirs calibrated like once every week (or maybe it was once a month I'm not 100%). So you know theirs will be accurate. Of course now that you know how fast it is knowing the weight probably isn't such a big issue. Also, if you go to the dyno, you can infer weight from your known rwhp and 1/4 mile time and ET. I'd nudge the boost down a tad bit... anything over 10psi is playing with fire w/o an I/C... not only due to the lean running but also the heat. Jersey was running 10psi on his setup with no I/C, and did mention that as soon as he nudged the boost up past 10psi he started getting detonation at the end of his runs. Either way very good times for a ZX, congrats. Quote Link to comment Share on other sites More sharing options...
Thumper Posted October 24, 2004 Author Share Posted October 24, 2004 Thanks guys. I am actually planning on doing some more weight removal soon just to see how light I can get it. I am not going to remove any thning critical or any support metal just little stuff maybe 50lbs. I will definitely weigh it again after I remove some more stuff. There is a chassis shop down the road that can corner weigh cars so I might get them to do it for me. At the track I put some 104 octane in it just for some fun; that is why i upped the boost a bit. Although when I did my mph never went up. Actually my fastest time was .4 mph slower than my second fastest time. But on the street I am running 9.5psi at 3k and at 6k 10psi. I have alittle boost creep problem, but then again i'm running long lines for my mbc so that I can adjust it without burning my hands on the manifold. Well I keep you guys posted maybe I can get it under 2500lbs Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.