96capricemgr

iTrader: (1)

Good point, if someone shifted at the 5800rpms Comp lists as the top of the range for that cam it would decimate MPH because you would not get near the top of the power curve.

With untouched heads I would expect it to want 62-6300 easily and with good ported heads 6500 for sure.

Snkebait95

iTrader: (16)

First passes id launch at 3-3500 rpm and shift at 6k and would net around 14-13.8. Then by launching at 5k rpm and shifting at 5800-5900 i got down to 13.5s. I thought Shifting around 6200-6500 might bend a rod or something on a stock bottom end? Is that false?

SexyTransAm

iTrader: (6)

with my cc503 on the dyno it was still making power at 6200 with stock unported heads.

trilkb

iTrader: (4)

what was your 60' on that run?

And you still havent answered what rpm it was shifting at.

If it was a 2.1 or higher then thats your issue. Knock it down to a 1.8 or so and your looking at a high 12 second run. 1 tenth on the 60' means about 2 tenths on the 1/4. So a 13.4 with a 2.1 60' would be a 12.8-ish with a 1.8 60'.

I would expect since its a 6 speed thats lowered, the launch is your problem.

I would ditch the lowering springs for stockers and do the lca relo brackets.

But everyone still needs to know what rpm it was, this effects a cc503 hugely.

Snkebait95

iTrader: (16)

I said where i was shifting above, around 5800-6000. On the 13.5 run the 60 ft was a 1.90

Puck

iTrader: (17)

5800-5900 is way too low. Try shifting at 6300 and see what happens. I wouldn't go too far past 6300 on a stock shortblock too often though...

Also, like stated, in a lowered car LCAs and relo's help a ton. I wouldn't be surprised if the back of the LCA is higher then the front.

Snkebait95

iTrader: (16)

The back of the lca is higher than the front lol

pancho toco loco

iTrader: (8)

Also remember most lt1's tachs are off by about 200-300 rpms. So your 5800 could only be 5500, thats 1000rpms short of optimum... Thats a big difference

trilkb

iTrader: (4)

My bad i missed the 2nd page somehow the first time.

You just need to up the shift point rpms. More times then not a 6300rpm shift isnt going to do damage anything, but of course some people just get unlucky.

Snkebait95

iTrader: (16)

Also, my cat and y pipe arent welded so theres an exhaust leak. Do you think un hooking that next time would be a good or bad idea?

Snkebait95

iTrader: (16)

That 1.9 60 ft was by launching at 5k also.

CamaroRacing12

iTrader: (5)

shift it at 6300rpms if u arn't in the 12's there is something wrong with the car and/or tune

pancho toco loco

iTrader: (8)

Well Id get that taking care of. Sometimes a loud leak can cause false knock. Not the standard but it has happened. Like said before shift at a higher rpm. You can spin a stock short block to 6600rpms. I wouldn't do it everytime I drove the car but under racig conditions I would. I mean how often are you really rev'ing the **** ut of your car? Like I said before between the factory tach being off by on average 300 rpms during wot in th upper rpms and you shifting at 5900 your leaving alot on the table. Go out and try shifting when you feel the car nose over. Where that rpm is try shifting just before that. Thats how I set my rpms on my car. Its way above factory shift points for a stock cam but then again how many bolt on lt1's trap 108 on a 80 degree day with 1400ish DA

gregrob

iTrader: (8)

I highly doubt the car picking up 9mph by shifting a little higher. Unless the tach is way off and he's shifting at 5500ish. I would put a shift light on it. Read the plugs, look over the tune, give it a tune up etc.

Snkebait95

iTrader: (16)

Ok heres what ill do in the matter of two weeks and see what happens...
-swap in a 3.73 rear end
-buy some adjustable lcas
-maybe even put my stock springs in the rear for the day
-get the y pipe and catback welded

Puck

iTrader: (17)

I can see close to 9mph gain if he is shifting a cc503 car at an indicated 5800.

That means he is short shifting at the most 5700 on a cam that will easily pull to 6200, even on stock heads. He should be shifting above that, at 6300+...preferably 6500 if he thinks his engine is in good condition.

I'm sure his tune also is leaving some potential on the table, but shift each gear almost a full 1,000 rpm early and see how much mph you drop .

quik95lt1

iTrader: (7)

that wont bend a rod...........i took a stock crank/rod combo (w/ARP bolts) to 7000rpm for four years and never broke a thing .......

yea thats no good lol

holy high rpm lol....

yea something doesn't seem right.......i mean if the DA was 7500 feet it kinda makes sense but other than that i figure that should be a 108-110 mph car all day long.......even if hes short shifting i dont see 8 mph........gotta be something in the tune...........