HumpinSS

iTrader: (1)

Hell I run 12.7 with a 1.9 short time with a stock cam no headers and two bolt-ons

4.10 and LM.

PREDATOR-Z

(Maybe it's the "mighty cam" we have)
ShuuuuT, let's keep it a secret.LOL

Ohmyneck

Blah you suck! I'm not at Sea level, in fact i'm 1,100 feet above and with 1/2 tank of gas, bald street tires, and a windy *** day I got a 13.3 @106 with a 2.1 60" If i can get my 60" times down and lower my weight and get tires I might be able to net a 13.1-13.0 depending on if i can get a better 60'. The only mods I have are Dynomouth, and SLP air lid on an 01 SLP SOM Firehawk M6

McRat

I've run 11.8 with less mods. On a 90 deg day.

What has it got to do with spinning a manual car fast enough to take advantage of a huge cam?

I would guess that someone willing to spin their M6 high enough to use the powerband in the TRex will see a significant drop in ET's over a smaller cam.

PREDATOR-Z

No one in particular, I just meant "the times" for such a cam.
I plan to do mid-low 11's with a 216/220, 1.8 rockers, PP 5.3's sage II (race). Stainless works LT's, March pulley and perhaps (and last) a Meziere.N/A and I'll never brake 6400 rpm
and 10's on spray (My cars like drugs)

HumpinSS

iTrader: (1)

was that with the F-body or the Y-body ala ZO6

SMOKIN01TA

iTrader: (10)

yea, but im sure you like to street drive it alot, im just looking for a weekend warrior and track car. so rpms dont bother me that much. and i plan on doing around 10.7 when i get heads and go on a diet.if it holds. if not ill go forged and bump compression and try to beat jasons solid roller time with a regular setup.

My84Z

iTrader: (18)

My cam is alittle different since it is a nitrous grind and will make power alittle earlier but even if I was shifting at 7k it would fall to the lowest 63 64. So I think it should be right in the power band. My cam is on a 114lsa and 6 degrees of timing so I think my peak would be closer to 66 67. I agree spinning it up that high alot would destroy a stock motor but you're not gonna be spinning that high while driving around only when your racing and I don't know about you but when I race I race to win or at least do the best I can wich takes more power. with the right springs and pushrods you should be able to spin safely to 6800 7000 for a while. I have seen many h/c cars last 20k or more shifting at 6800. If I get 20k out of my motor with a big cam I would be happy as I think anyone who races there car shouldn't expect more then 20k out of a motor for racing.

Colonel

You know the problem with a BIG cam in a wide ratio tranny such as T56? YOU CAN'T spin the engine high enough to keep from bogging on the shifts!

You're second gear (1.78) is only .669 of what your 1st gear is (2.66.) If you shift at 7000 then you're going to end up somewhere not too far above 4700 going into second. Cams with peakier (narrower) powerbands exasperate this problem. It's part of the reason that dyno numbers keep going up with bigger and bigger cams but yet the time slips mysteriously don't reflect it.

With an auto car and a big 'ole sloppy stall we can deal with the narrow powerbands alot more effectively.

Just something to think about.

Scalpel

iTrader: (4)

That makes perfect sense.

gator's 99TA

iTrader: (2)

hmm maybe now someone will believe me - thanks colonel! you hit it on the head!

t56 trannys - i love it when idiots talk about not droping much rpms between shifts because they A) powershift B) rearend gears or C) worse they think they are just amazing drivers able to fight physics.

take a look at 4600 rpms. if you arent making killer power there, then you just got sold on a big new cam.

Scalpel

iTrader: (4)

I think you should replace "you just got sold" to "you just got

McRat

You will need more than 7000 to take full advantage of the cam. 7200-7300... IF you are willing. It will probably rip shifted up there.

Colonel

"t56 trannys - i love it when idiots talk about not droping much rpms between shifts because they A) powershift B) rearend gears or C) worse they think they are just amazing drivers able to fight physics."

Let's talk about this a little more so that people can understand what they are seeing if their tach doesn't drop back to only .669 (again, 1-2 shift) of the RPM that it was at the moment of shift initiation. Clutch slippage. The more you slip, the more power you convert into heat (that's power that could have been used to propel your forward.) If you powershift and notice less RPM drop than the theoretcal calculation it is because of more slippage and a SLOW TACH. The factory tach is sllloooooooooooooooooooow. The quicker things are happening, the farther off it is. That can also give you the false impression that extra rearend gearing helps your RPM drop on the shifts. The RPMs rise faster fooling the tach more.

Also, contrary to some people's belief, when you disengage the clutch you are NO LONGER accelerating....I don't care HOW quickly you were accelerating before. If you disconnect the pushing force from the object that is being pushed, THE BEST it can hope for is to maintain the present velocity (and this only works in the absence of friction, drag, and gravity.) So no, this isn't an overlooked factor.

If you remove the clutch slippage factor, your before and aftershift RPM difference will be exactly the percentage difference between the transmission gear you just left and the gear you have just entered. Rearend gearing will not effect this. There is NO getting around this. You're stuck with the same RPM drop unless you change the gearing of the tranny. Word to the wise...choose your cam (and your entire engine combination) with this in mind.

Now of course, extra gearing will help to get you back OUT of the RPM hole you've dropped yourself into. No doubt about that. But that's a bandaid fix way of thinking about it. It's not optimum. And, there's only so high you can go on the rearend gearing before you're forced to shift into another gear short of the finish line. NOT good.

Colonel

Even if you shift at 7500, your RPMs will drop back to only 5017 on the 1-2 shift (not counting clutch slippage.) It'll be a little better on the 2-3 and 3-4 shifts (5475 and 5768 respectively.) I'm NOT saying it's the end of the world that this is the case. I'm NOT saying that M6 cars absolutely shouldn't run this cam. I am only saying that one should be aware of this and ponder it's implications before choosing to run this cam in an M6 car.

McRat

The 1-2 isn't as important as the other shifts. You spent very little TIME there. This is one reason the F-body T-56 is actually better for dragracing than the M-12 version.

With the M-12, you always drop out of the serious power on every shift, and that's why it goes much faster when you over-rev it. The amount of time you spent in the bottom of 4th trying to climb into the power sucks. But it is KILLER for 1/8mi ET's. The F-body version doesn't drop near as much going into 4th.

There is no secret why it makes killer peak HP numbers. All else being equal, you will make more ponies at higher rpm than lower.

But I am not going to rev the stock lower end over 7000. So the T-Rex is probably not the right cam for me. I need the power to start to drop at 6500, so I can shift at 7000 and use the fat part of the curve.

But is sure is interesting. Might be fun with a big-bore forged bottom.

Coach 02 A3 Z/28

iTrader: (10)

Very interesting thinking going on here. Makes me wish I still had my M6. I would dig trying this cam. Maybe I will find out with a A3.

Coach

White Fire

The way I see it, this cam has made boatloads of power but hasn't did jack **** in terms of quarter mile performance.

SMOKIN01TA

iTrader: (10)

that could have alot to do with the fact that 95% of the cars making good power with this cam havent even been to the track yet.

SMOKIN01TA

iTrader: (10)

my car is making peak torque in the 4600-4800 range. ill be shifting it at 7000-7200 range. so i think it will stay in the power band quite nicely for the most part.