88Trans-am

Ok guys, I have built a 96 stock bottom end 350 with vortec heads.
Cam is cc503 218/224 it has an hsr, short heading into single 2.5 inch exhaust. Adjustable fuel pressure regulator set at 45 psi. Wide band is showing 13.0 at wideopen throttle...well I had a buddy help me with some tuning.. And it feels strong as hell.. But 14.2 @ 97 in the 1/4 mile??? 3.27 gear,700R4 tranny with shift kit... I was expecting more of a mid 13 second time... Any thoughts?
Thanks guys

86LG4Bird

iTrader: (1)

Number one culprit is that 2.5" single exhaust. It will limit you to about 250 rwhp, which, depending on your weight and other vehicle factors, could explain that low 14
With the exhaust restriction, sure it will feel strong/torquey.............until it gets over 4k where it should really start making power.

Is the cam a CC502 (218/224/112) or a CC503 (224/230/112) ?

What kind of torque converter? What tires? 60' time? Regardless of power, those are the things to look at, if you haven't already, to get into the 13's.

Orr89RocZ

iTrader: (20)

97 is good for 13's but it should be doing more like 105-108 imo. Whats the car weigh?

I figure you for 300 whp or so which will drive a 3400 lb car to 108-110 in optimal conditions, or a 3600-3700 lb car to 104-107 ish give or take

Could also try more fuel when fine tuning, it may like more. How much timing and where you shifting at?

RyanJB

Did you manually shift it or did you leave it in OD? I lost almost half a second that way. I went 13.7 completely untuned on my Vortec 350 with HSR and LT4 hot cam with 2.77 gears.

88Trans-am

Car is stock stall... Cc502 on the cam sorry. It is stock stall converter. 60 ft times are 2.12. I used a set of cascar slicks..but realized after I was not hearing them up fully..I've done both manual and OD SHIFTING....WHEN IN MANUAL I shift about 5700...overall the car feels strong...I wouldn't think adding more fuel would make it go any quicker... Base timing is at 10 degrees and I don't know how much timing in full I am running..I wad going to start looking at the timing aspect but my wideband crapped out on me at the track....I plan on running longtubes and a stall next year providing the funds..but if like to break 13'a within the next few weeks if I can.

Orr89RocZ

iTrader: (20)

3000 stall and you have it

And verify your timing!!

88Trans-am

I'll verify the timing as soon as I can...but how much am i reallygoing to gain (et wise) with a stall?...I figured the car would be mid 13's with a stock stall no? I could understand my exhaust holding me back some.

Jonesyfxr

iTrader: (2)

A converter will make or brake a combo.

My buddy has a 427 SBC in an 81 Camaro. He had a holes hot converter and was running 7.50's in the eight. I knew the car had more in it, as did the engine builder. He had a BDR (local converter guy) build him a converter. The first run out it launched like an animal and ran a 7.21 just from a converter change!

Get a converter to match your setup, you won't be disappointed.

cuisinartvette

X2
Slicks can slow you down also
Ever notice when they are used on a dyno even some DRs, the #s are lower.

86LG4Bird

iTrader: (1)

Not everything you see on a dyno is relevant for ET's.
Unless you're talking about a 200 hp motor with a stock TC running 15's, slicks or DR's are your biggest bank per buck for ET.

TTOP350

iTrader: (8)

Wow, that's slower than my 89 formula 350 was stock with a tire.. ouch.

converter, trans rebuild, tires and 1 3/4 dyno don headers and atleast 3" exhaust.

Orr89RocZ

iTrader: (20)

Keep working the tune as well. Timing map and fuel can add up a good deal of hp

88Trans-am

Ya...see my problem lol stock l98's with bolt on are moving faster lol
ORR...which timing map are you taking about? Spark advance table?my buddy is helping me out with this tuning, and he had done a great job so far...I like second opinions also...my tranny doesn't't feel bad at all...it was rebuilt before I got the car several years ago..but I have not put many miles on it.shifts firm....I'll look into a stall for sure. Going to get back out on Friday after playing with the tune and I'll post up new numbers...not sure if I will use slicks or not..but I'm running 18's if I use my street tires....

Orr89RocZ

iTrader: (20)

Yeah my L98 with stall headers exhaust went 13.63 at 97 on slicks. Cold weather tho. Bolt ons went consistant low low 13's

Yes i was refering to timing in the spark advance table. You should see 34-36 deg at peak hp rpm at 180-208 lv8 columns for best power on pump gas and basically have all of it in by 3000 rpm or so, with few degrees less between 2400-2800. Thats what worked well for my L98.

Jonesyfxr

iTrader: (2)

The 60ft is killing you. I would have somebody video your launch, from the back side....watching the tires. See what your chassis and tires are doing. It might just be tha way you launch your car.

My body has a completely stock Goodwrench crate motor is an 81 El Camino that 60 ft better than your car.

Tell us your burnout/ stage procedure.

88Trans-am

My stage procedure goes as follows...tranny in first gear, do a medium burnout.bring the car to about 5000 rpm and sort of feather the throttle a bit around that range... Let off brake with tires spinning.. Pull up,stage one foot on brake and one on gas while still in 1st. Bring RPMs up to about 1200 or until the car barely holds on the brakes.. Go a bit before green..... That's it.. I've tried no burnout,burnout and take off in OD. Take off from second...my times are consistent.

Orr89RocZ

iTrader: (20)

With no converter your 60 foot is about right and its going to be dead consistant and really not dependent on burnout or launch technique.

My bolt on stock stall ls1 used to do 2.04 all day long. And run 8.5 1/8 mile all day long. Add converter i went 1.66 and 7.7 1/8 mile

88Trans-am

Well I guess a stall will be what I Get for next year..I'll head out on Friday night and try the timing and fuel..see if I can't break that 13 second mark.thanks for all the advice....keep it coming if there's anything Imaybe missing.

Cheers