wheelman Posted May 2, 2007 Share Posted May 2, 2007 This last weekend I attended an Auto-X event in Yakima, WA and one of the participants opened his shop so a few of us could do some dyno pulls. The Z generated 274HP @ 5700 rpm and 307 Ft/lbs @ 3500 rpm. The Torque curve is very flat and starts out at just under 250 ft/lbs @ 1500 rpm and rises from there to 307 @ 3500 rpm then drops slowly to about 225 ft/lbs at 6300 rpm The HP curve starts at about 100HP @ 1500 rpm, rises in a smooth curve to 274 @ at 5700 rpm and falls to 250HP @ 6300 rpm. Not quite as high as I figured but I'm still very happy with it. The AFR showed around 13.5:1 until about 4700 rpm and then richened to around 12.7:1 by 5600 rpm and stayed there. I'm happy with that, right in the power AFR range and very stable. The next thing I'd like to explore is what the timing is doing. Find out if the knock sensors are detecting anything and pulling timing. Also experiment with adding or removing a degree or 2 to the base to see how it acts. Doing all this on a dyno gets pretty spendy though so I might have to settle for the Butt dyno. Wheelman Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted May 2, 2007 Share Posted May 2, 2007 I'm on the Butt Dyno program as well. I am going to the track this weekend but that's still expensive (tuning). Quote Link to comment Share on other sites More sharing options...
Challenger Posted May 2, 2007 Share Posted May 2, 2007 Do you know the stock #'s for the LT1? Howd you do in AutoX? Where are they doing autoX in Yakima? Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 2, 2007 Author Share Posted May 2, 2007 The stock #s for my LT1 are 260hp and 330 ft/lbs. It came from a Caprice 9C1 and was setup more for torque at low rpms. Edit: The dyno numbers are at the rear wheel and the stock #s are at the flywheel. I think the general assumption is the drive train consumes 15% so the flywheel HP should be 315 and torque 353. I swapped in an LT4 hot cam which pushed the power band up higher in the rev range. The event was at the SunDome and was hosted by the club I belong to thats based in the Tri-Cities. We usually host 1 event in Yakima and 1 in Packwood every year. The club class I run in is a combination of all the SCCA Prepared and Modified classes so it can include very fast cars. On Saturday there were 6 cars and I came in 3rd. On Sunday there were 3 cars and I came in first. I have a couple videos but I'm not sure how to post them yet, once I figure it out I'll post a link. Edit: Here is a link to 1 of my runs on Saturday. http://www.youtube.com/watch?v=Azjf_6PF2uo Wheelman Quote Link to comment Share on other sites More sharing options...
Bartman Posted May 2, 2007 Share Posted May 2, 2007 Hey Ken, I don't know that I've actually seen pictures of your car before; but it looks great in the video. It looks like you were really laying down a good fast run there. I would really like to get my car on the dyno and see what I've got, but I just haven't gotten around to doing it yet. It looks like autocrossing would be fun to do as well, I think I'm going to try that in the near future as well. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 2, 2007 Share Posted May 2, 2007 Nice video. The car looks really stable and smooth. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 2, 2007 Author Share Posted May 2, 2007 Bart, Yeah, I don't think I've posted any pictures here in quite a while. There's still LOTS of body work to do but it looks decent from a long distance. Those rims don't hurt either, they draw your eyes away from the really rough spots. Auto-X is a blast, if you give it a try be prepared to be addicted from the first run. That run was actually one of my slower ones of the day. My fastest time was a 41.8 second run which is about 1.5 seconds faster than the one in the video. Cygnus1, The car is very stable and smooth. I've installed 225F/250R springs along with the MSA sway bars which really helped limit body lean and the Falken tires make for good handling. I managed to spin it again on Sunday though. There was an off camber corner transition where I came in hot and lifted throttle just as I entered. Shifted weight forward and around she went, almost got the timing lights. Wheelman Quote Link to comment Share on other sites More sharing options...
ProjectSR20 Posted May 2, 2007 Share Posted May 2, 2007 Looking good. I wish I knew you guys were going to be in town. I would have loved to have seen you run to get some inspiration to get me working on the Z again. You guys have any more runs planned around here? Quote Link to comment Share on other sites More sharing options...
piston Posted May 2, 2007 Share Posted May 2, 2007 im not sure how you guys do it but in mine without power sterring, it looks like ill be going into someone else car if i was to do it. in the back of my head when i gun it and turn it on corners, my mind goes negative and think somethings going to break. probably because i built the car and have doubts about it. the chasis just dont seem like its strong enough, but when i think about you guys and alot more horses you guys put out and all the driving and turning, im more confident. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 2, 2007 Author Share Posted May 2, 2007 Piston, I've installed sub-frame connectors and went through the car eliminating alot of rust. There's still rust in there but the major sections have been removed. I've also replaced all the bushings, installed sway bars, coilover springs, camber plates, new struts, CV joint axles, LSD, etc.. So I know pretty much every inch of this car and am confident in it. When I first Auto-Xed it I was concerned about the tranny holding up but it seems to be doing fine. I don't have power steering either and my arms have gotten pretty sore at a couple events. This one wasn't bad at all, but it also wasn't as tight as some we've set up. I consider installing PS from time to time but then I have to take everything apart again, maybe when I rebuild the tranny and/or motor. ProjectSR20, Yeah, It's to bad you weren't aware of the event it would have been nice to see another Z there. As it was there were 3, a 280, my 240 and another Turboed 240. The club normally does 1 event a year up there and 1 event in Packwood all the rest are local to the Tri-Cities. If you want to attend an event the club's website is www.ssscc.org. The full season schedule is there. If you decide to come down for one let me know and we can do lunch or dinner, maybe have a beer or 2. Wheelman Quote Link to comment Share on other sites More sharing options...
piston Posted May 2, 2007 Share Posted May 2, 2007 nice, im always worried about my tranny mount. i would stop and get out and look under my car to see if it still looks good. it does everytime. im just going to bash thing thing with no worries next time, i would hate to get towed home. i cant afford anything to break. my car has no rust issues and its actually a pretty clean straight chasis come to think of it. thats the only thing i can use to help myself drive this thing a little more agressive. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted May 3, 2007 Share Posted May 3, 2007 So is everything else stock in your motor(pistons, heads, injectors, throttle body)? Man I have the hotcam too but I am hoping for higher numers than that, more like 350. I have ported/polished heads, raised compression to 11:1, larger injectors, and 58MM TB. The cam feels pretty good but I think I'm going to be dissapoited when I get to a dyno and at the dragstrip...I want to run 11's all day long in full street trim. So is this enough power for you or are you going to upgrade the heads and cam to something a little more radical? Guy Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 3, 2007 Author Share Posted May 3, 2007 Everything but the cam, valve springs and flywheel is stock. I'm running a stock Camaro MAF which is 3.5" vs the B-Body unit which is only 3". I'm also not running any emission equipment, PS or AC. I have messed with the PCM tuning a little and the AFR was pretty good but I don't know how good the timing is. The heads are iron B-Body heads which are supposed to flow better than the aluminum ones but who really knows and the CR is only 10:1 instead of 10.5 or 11:1. Wheelman Quote Link to comment Share on other sites More sharing options...
Z48LT-1 Posted May 3, 2007 Share Posted May 3, 2007 Wheelman, Your numbers are pretty impressive, IMO. Looks like your tuning has wrung every last particle of performance out of that cam. A gain of 55HP and 23 ft-lbs over the stock 260/330 (which we all should acknowledge may be optimistic) with the few mods you've done is sweet. Have you told us how many miles are on the engine? What about headers/exhaust? Looking forward to getting my lump running and on the dyno; it's a 33K (alleged) '95 Caprice motor/4L60E which will initially have only block hugger headers, true duals, and possibly some 1.6:1 rockers and fresh valve springs. Speaking of which, you didn't mention rockers. Did you use the complete hot cam kit with its 1.6 roller rockers? Did you start out with a mail order tune or do it yourself from the get-go? What year PCM/harness? I suspect I've read all the answers to my questions from previous posts but hope you don't mind updating my memory and putting the whole story together now that you've got the new numbers. Finally, while we're putting it all together, what tuning tools are you using? Is data-logging important to your success? Best -- Gary PS Cold air intake? Throttle body bypass? Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 3, 2007 Author Share Posted May 3, 2007 Ok here is whole break down. 95 B-Body LT1 (iron heads) ~102,000 miles when pulled from donor 3.5" F-Body MAF LT4 Hot Cam Stock lifters High rev valve springs Stock rockers (for now) 15 lbs flywheel Stock Throttle body but bypassed Home built cold air intake with huge K&N filter All emissions equipment removed & disabled in PCM (egr, air pump, etc..) No PS or AC I Started with a tune from PCMforLess and adjusted to work with larger MAF and my T5 tranny. Headers are Hedman Tight Tubes. (Shorty Block huggers, 1 5/8" primarys, 2.5" collector) The remainder of the exhaust is 2 1/4" dual into 2 1/2" single and a Hooker Aero-Chamber muffler. One thing to remember about the original configuration of these B-Body LT1s is they are setup for low end torque so swapping in a hot cam will do more for them than it will for an F-Body LT1. I've also seen data from tests that show the iron heads flow about 20% more than the aluminum ones so again the cam swap will have a larger impact, assuming the higher flow rates are real. Before I dropped the engine into the Z I pulled a main bearing cap and 3 rod bearing caps to check the condition of the bearings. They showed some wear but were in good shape so I waited on a rebuild. I think there are a few places I could gain more power without pulling the heads. The exhaust is a bit restrictive and hurts the top end. Rockers would help and possibly a bigger throttle body but I'm very skeptical that these do anything to help overall power until the engine is pulling a hell of a lot more air than mine ever will. Playing with the timing might gain me some as well, thats my next area of experimentation. Edit: Forgot to mention I use TunerCat and DataMaster. Yes data logging really helps to understand whats happening with the AFR, timing, closed/open loop, etc... DataMaster is real nice but spendy so I use the "demo" version that lets you log for 30 seconds so it can be a bit tedious. Hope this answers your questions. Wheelman Quote Link to comment Share on other sites More sharing options...
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