Low MPH with Hotcam
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From: Crappy Stupid Liberal Washington state
Are you taking into account for the possible weight of the car? Weight WILL affect trap speed
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From: Raleigh, NC
Mine was right around 3570 with me in it back when I ran those times, and with the CAI, catback and shorty headers was 295rwhp. Trapped upper 104s to low 105s in the heat, solid 106s in good air. 1997 Z28 M6 with stock-sized wheels/tires, nothing removed except spare and jack.
A hotcam/bolt-on car should make at least 320rwhp and I've seen a few make in the upper 330s and low 340s.
So yeah, unless there is a few hundred pounds of lead wheels weights in the car, the driver is enormously huge or has no idea how to drive or both, something is amiss. Even a heavy convertible LT1 f-body with these types of mods and a sub-200 pound driver should trap in the 108s if everything is working correctly.
If the OP is interested in seeing the 108-110 mph trap speeds commonly associated with properly tuned hotcam/bolt on LT1 f-bodies, I would suggest he get with a tuner who knows LT1s, put it on the dyno and see what sort of power it's making and why. Everything else in this thread is just speculation.
A hotcam/bolt-on car should make at least 320rwhp and I've seen a few make in the upper 330s and low 340s.
So yeah, unless there is a few hundred pounds of lead wheels weights in the car, the driver is enormously huge or has no idea how to drive or both, something is amiss. Even a heavy convertible LT1 f-body with these types of mods and a sub-200 pound driver should trap in the 108s if everything is working correctly.
If the OP is interested in seeing the 108-110 mph trap speeds commonly associated with properly tuned hotcam/bolt on LT1 f-bodies, I would suggest he get with a tuner who knows LT1s, put it on the dyno and see what sort of power it's making and why. Everything else in this thread is just speculation.
I'm going to try to get it on a dyno in the next few weeks. I had the car mail order tuned by madz28 or mad tuner whatever their name is. I had read a lot of good things about them with hot cam only cars so i figured that would be a good tune to go with.
Probably losing at least 1mph or more on that 60' alone.
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From: Crappy Stupid Liberal Washington state
I don't know how everyone has such a lighter car than I do. I weighed mine last week and it tipped the scales at 3950 with me in it (I am a pretty big guy, just over 300 lbs). Without me it's obviously just over 3600.
I would see around 12.8 @ 104 1.6 60'. Somewhere around 3800 lbs. I never saw 320 on the dyno. I think the numbers HellTeeOne is talking about aren't as common as he thinks, at least for us A4 guys.
a Hotcam, Mid-Headers, Tune M6 car should trap around 108-110.
Last edited by kinglt-1; Jul 31, 2014 at 11:09 PM.
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From: Raleigh, NC
IMO, there are too many variables with A4 cars (type of converter, etc.) to closely equate dyno number with given trap speeds.
Most full bolt-on/hotcam M6 cars I've seen dyno at least 320, with most in the mid-330s. The most I've seen a hotcam/bolt-on/stock heads car dyno through an M6 is 345, solidly in CC503 territory. I was surprised to see that number.
I've seen 320+ through A4s more than once with the hotcam also, so the difference isn't that dramatic.
Either way, the OP's 103-104 mph trap speeds point to around 280-300rwhp through an M6, depending on how much the car weighs. With his mods he should be 30-50rwhp higher than that IMO.
Could be a multitude of things causing that. I'd hit the dyno and see if it were me. Could be the tune is off (not particularly likely IMO), could be a fuel pressure or spark problem, could be the lash is too tight, valve float from the crappy springs that come with the hotcam kit, clutch could be slipping, anything really.
Having the same Madz tune as Wallj I'm inclined to think it is not that. His 1/8 mile performance is suffering from the tall 18" tires turning his 3.42s into 3.23s. Any cam needs steeper gears to really perform. Gaining 24 mph out the top end with the long pull in 3rd tells me there's power there, just can't put it to work out of the hole.
I agree he should be trapping 108+ but don't solely blame his engine when there are many other variables that are not optimized for 1/4 mile work.
Last time at the track I picked up 1.5 mph from powershifting vs not, my HP didn't change. With a M6 driver skill plays a large part in the numbers run.
I agree he should be trapping 108+ but don't solely blame his engine when there are many other variables that are not optimized for 1/4 mile work.
Last time at the track I picked up 1.5 mph from powershifting vs not, my HP didn't change. With a M6 driver skill plays a large part in the numbers run.
Last edited by guppymech; Jul 31, 2014 at 01:10 PM.
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From: centerville, ohio
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the springs in the hot cam kit were designed for LT4 heads using sodium filled valves (lighter). Using the solid LT1 valves are heavier and those springs are weak under those use conditions. A better set of springs to allow 6400 RPM shifts would help...so would gears and a tire
this assumes there are no tune or other mechanical issues affecting performance
this assumes there are no tune or other mechanical issues affecting performance