Low MPH with Hotcam
Low MPH with Hotcam So I had my car at the track for the first time in over a year. Over the winter I installed the LT4 Hotcam Kit. Anyways my times aren't impressive at all with my horrible 60' times. However I just installed a new clutch last week so I'm still getting used to it. My issue is that I feel like my mph at the end is extremely low for a bolt on hotcam car. I thought that even with a bad 60' your mph should still be fairly normal. So let me know if you think it's ok or if something is wrong. The car is a 97 z28 M6. I'm shifting at 6100. Mods: lingenfelter CAI, 93-95 style Mac mid tubes (better version than the 96-97 style) borla adjustable exhaust with flap completely open, hotcam kit with the 1.6 rockers and all, madz28 Tune, founders LCAs and Adj. panhard. Running on 285/40/18 Goodyear Eagle F1.
Here's my timeslip, I'm on the right (D21):
Here's my timeslip, I'm on the right (D21):
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Do you know your race weight? That will also play a big part in your MPH. If your race weight is around 3700-3800 that'd put you right at 330-340 HP, which isn't at all bad for a Hot Cam bolt on car (especially with mid-lengths).
Those 18" tires are not good for drag racing, the 285 tire is almost 27" tall. Do you still have 3.42 gears? You should be going through the traps in 3rd gear not 4th. If you have 4.10s then of course use 4th and stay out of 5th. You're picking up 24 mph in the back half which is good. You need to work on the 60' time, but you know that.
Did you race at that dump 'No Limits' in Morocco IN.? What was the density altitude?
Did you race at that dump 'No Limits' in Morocco IN.? What was the density altitude?
I raced at Lucas Oil Raceway in Indianapolis. The elevation is 700 I believe. Not sure what the DA was or how to find it. I raced July 19th at around 5pm. I don't know my exact race weight but it has no weight reduction whatsoever. Still have the spare and jack in it even. Plus me which is an extra 160. I'm going through the line at the very top of 3rd literally right as my shift light is coming on. Yes I do still have stock 3.42s. Also, I'm pretty positive I set the valve lash correctly. I followed Shbox's guide and have that nice low sewing machine sound without any abnormal knocking.
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With you in the car I would guess the car weighed around 3800 (give or take 25 lbs depending on how much gas was in the tank). That puts you around 340 to the wheels. That really is pretty good for a hot cam only car.
are you suuuuure its a hotcam? my 93 m6 was faster than that bone stock (albeit 3.42 gear). it went 8.0's @ 81mph iirc. no weight reduction, and i probably weighed around 160 back then.
see if you can put it on a dyno somewehre and see whats going on.
see if you can put it on a dyno somewehre and see whats going on.
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Even with your heavy 18in wheels and no weight out of the car you should only be around the 3600 area. DA was around 1700ish for you that day and time. ET corrects out to 13.7x's at around 106mph. I'm gonna say something is a miss. First off Id be shifting higher then 6100 with a hot cam. Im programmed to shift 1-2 at 6250 and 2-3 6150 stock cam auto. Being a stick car Id do a few test runs and hold the shifts and see where the power falls off then shift just prior to that and set your light accordingly. Id say a hot cam would want to be shifted around 6400ish. From there Id start working backwards from the plugs to wires coil to opti. My car ran great last season and at the start of this season was running fine then the opti died, new one in and I magically picked up a .15 and over 1 mph in the quarter. So you nvr know whats going on
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Verdad Gallardo I shift my hotcam at 6k, tried 6200 for a few runs and saw no increase in trap speed. When I had the LT4 springs with 1.6 rockers I had valve float at 6k, better springs cured that. IMO the LT4 springs are no good for the hotcam with 1.6 rockers. The tall tires are knocking your 3.42s down to 3.23s or so. If you get any extra $$$ some 4.10 gears will work good with the hotcam.
Here's a link to a Density Altitude calculator, just enter the track, date and time info.
http://www.dragtimes.com/da-density-...calculator.php
Here's a link to a Density Altitude calculator, just enter the track, date and time info.
http://www.dragtimes.com/da-density-...calculator.php
Last edited by guppymech; Jul 23, 2014 at 08:58 PM.
car had about 3/4 tank of gas.
It just seems weird though, i read about all these bolton hot cam cars running like 110+and I'm nowhere near that.
Also, plugs and wires are new but i don't have any symptoms of the opti going out, hopefully thats not the case.
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I'm positive its the hot cam, i installed it myself as the whole kit.
car had about 3/4 tank of gas.
It just seems weird though, i read about all these bolton hot cam cars running like 110+and I'm nowhere near that.
Also, plugs and wires are new but i don't have any symptoms of the opti going out, hopefully thats not the case.
car had about 3/4 tank of gas.
It just seems weird though, i read about all these bolton hot cam cars running like 110+and I'm nowhere near that.
Also, plugs and wires are new but i don't have any symptoms of the opti going out, hopefully thats not the case.
Couple things. If the car hasn't been on a dyno, that is the easiest way to find your power peak and where you should be shifting. I think a hotcam properly set up should peak around 6000 to 6100? You should also be running a 4.10 gear and if you want good ET and MPH you need better tires. Get yourself some 16" wheels and BFG DR's, or go crazy and get 15" wheels with Hoosier QTP's. Probably would soften the blow on a 10-bolt, but use at your own risk. I'm sure weather conditions played a part in the lack of power as well.
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From: Valencia Ca
I would guess to be right around 3800-3850 lbs. With a trap of 103 you're right around 330-340 RWHP. That is where I'd expect a bolt on hot cam car to be.
Gotta know some cars are really optimized meaning suspension set up right weight, etc etc. Give them real good air and they turn times that make you wonder if somethings wrong when it may not be. Not everyone tells you all they do
Theres a user I think called Neat whos running 11x at close to 120 wiht the hotcam but hes had hundreds of passes and has been through the whole car head to tail.
You need gears. 3.42's are just too tall for that cam. 4.10's are perfect. I used to shift 6300 on the tach which was about 61-6150 actual. Gears will be a HUGE improvement.
Looking back on my old timeslips, I used to run 10.4-10.5@1000' at MIR. That was on a 1.7x short time with 275/40/17 Nitto DRs.
Looking back on my old timeslips, I used to run 10.4-10.5@1000' at MIR. That was on a 1.7x short time with 275/40/17 Nitto DRs.
You need gears. 3.42's are just too tall for that cam. 4.10's are perfect. I used to shift 6300 on the tach which was about 61-6150 actual. Gears will be a HUGE improvement.
Looking back on my old timeslips, I used to run 10.4-10.5@1000' at MIR. That was on a 1.7x short time with 275/40/17 Nitto DRs.
Looking back on my old timeslips, I used to run 10.4-10.5@1000' at MIR. That was on a 1.7x short time with 275/40/17 Nitto DRs.
Bone stock in 96, mine ran 8.7@82 and 11.3 in the 1000' and 13.5@104. It was one of the fastest stock ones back then.
Back in 98 or 99, there was a local guy that put a HOT cam in his Camaro but still had 2.73 gears(A4), it was slower than when he was stock. So it can happen. Once he changed the gears, he was finally happy because the car pulled like it was supposed to.
i know this... still dont see a 3.42 hotcam car trapping the same as a stock 3.42 car. the thing should have another 40hp once it gets moving at the top of 1st gear over a stock car. a converter would help more than swapping gears on a hotcam'd auto.
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A full bolt on car with a hotcam should be trapping 108+. He has issues somewhere.