I recently went to the track with my new motor , it has a little over 1000 mile son it now. The mods are as follows.
383 5.7 rods,10.3:1 compression, AFR out of the box 190 heads, 224/230 XE cam w/1.6 rockers,Hooker LT headers,3 inch Y,Flowmaster cat-back (duel out type),3.73 rear gears,M/T Sportsman Pros, Stock ram air system w/baffles removed in hood, stock maf, stock T/B,Stock weight of 3639 w/me,vig 3000 stall, 160 deg stat.
The tune was done by PCM for less through the mail and it runs slightly rich at times but at WOT the O2 readings are in the 930 range on both sides.
this is what it ran:

60 foot....1.72
1/8.........7.96
1/8mph..86.32
1/4........12.49
1/4mph.108.89

I made 5 passes and they were all in the low 12.5s high 12.4 range, the mph I showed was the best mph, the DA at the track was 2162 feet that day (very humid).

The only thing that puzzles me besides the mph is that it would hook pretty good and the at the top of first and second it would spin the tires and then rehook before the shift. I verified this with bystanders.The rear would jerk out slightly on the spins but not bad enough to worry about control I called it squirmy the day.

The car down low feels very very strong, I have raced on the street from a float a few 03 Cobras when I race them I tear away init and then they stop the progress at a few cars , me in front. I raced a modded Z06 (exh,headers,intake and RR) and he couldnt pass me til 120. (he runs the 1/4 in 11.86 @ 117) These races were all on the street from about a 30 float.

Why is my car down on the top end?!!!?

 

I think these things are part of the problem. That's a real conservative setup for a 383. Put the car on a dyno w/ wideband and see what you fuel & HP/TQ looks like.

If you want to do some comparative driving, I’ll be out this Saturday night.

 

Where ya hanging out at? I may head that way.

 

I agree...you're setup does seem too conservative for a 383...you need let it breath a little more...

 

What I would be looking for is..

RR adjustment...
degree cam in....(not much you can do about it now, but did you)
do AFR 190 heads flow well out of the box...(read they don't)
getting any knock retard...good gas next time...
any exhaust leaks...
vaccum leaks...
check fuel psi....
ring gaps...(not much you can do about it now, but pre-fit)

Your gonna have good low down power, stock rod length with a stroke. Why did you only go with 10.3:1 CR?

 

Oh yeah, your shift mph. A4's do not shift by rpm, but by MPH so if it is off, like let's say it is programmed to shift at XX mph with a 4.10 gear vs a 3.73...let's just look at my little example.

Let's assume a 500 rpm slip. Your rpm reads 6200 in the car.

4.10 vs 3.73
35 -- 39
66 -- 73
107 -- 118

Could be more or less slippage and what about tire height?

Does the car feel like it is shifting way to early?

Maybe the programming is correct but to much slippage was figured in?

Precisely why I bought LT1_Edit.

 

That weather isnt helping at all. Get the car dynotuned and get those shift points down, that will do a lot for you in the end.

 

The compression is on the cons side I went with the 18cc dish pistons which claim a 10.5 with the LT1s 58 cc chamber and a zero deck, I am not zeroed. The cam was not degreed with a wheel, I just lined up the dots. Rocker adj is ok. No exh leaks.
Car pulls good vacuume at idle. I did suspect a leak when it was first started so I sprayed around with WD 40 and found nothing.
The ring gap was set by me by hand on the tight side. I staggered the rings as I always do.
The heads were flowed by a local machine shop and flowed 254/203 cfm @550 lift, This was with an exh pipe and clay on the intake. These same heads ran a 350 with a cc 305 cam to 113 mph. (in my 93 T/A). I had the heads guides and VJ checked while I had the block being machined for the stroker.

My intentions with this motor was a 400 rwhp torque monster that would see the track about 5 to 8 times a year. which is why I went with the small cam. I am planning on moving up in cams here shortly after my track runs, but wanted opinions.

 

On the shift thing, The car shifts itself (unless I hold it past it manually) at just a tick above 6000, the M/Ts in the rear are 26 inchers.

 

To let you in on my thinking, How much would about a 1/2 point of compression and say a 230/236 XE cam w/1.6s improve it? (of course assuming the shortblock is sound, will do comp test this weekend)

 

With everything correct, you want it to shift by itself.

Try shifting at different rpm's.

I know when I first built a combo a few years back, I thought it would pull hard up to 6500 rpm, so I set my shift mph's based off that. I then dynoed my car and found out it made peak at 6200 rpms.

I then took it to the track before I changed the program and me shifting 300 rpms earlier than what the program shifted at (6500), I picked up 2 tenths and 1.5 MPH just from that little difference.

 

I personally think that small cams can be very powerful. You would be surprised how a smaller cam with heads that dont flow outrageous numbers can run really hard.

A combo I built a couple of years back ran the times in the sig.

388"
12:1 CR
heads flowed crap, 258/168@.600
cam was small, 226/236 .534/.561 on 114 ls (n2o grind)
broken main cap, broken piston
stock exhaust(from 3" y-pipe back)
some weight reduction, (a/c del, sway bar, bumper crap)
stock rims, stock most stuff
boltons

If that combo was in my car now, I am confident I could have gotten it in the 11.5's easily with more tweaking and a rebuild.

Idled great, held great vaccum, never a problem.

IMO

 

perry were you running @ thunder valley or where?

and where are you 2 going to meet up this weekend? I may have to meet up too, Im wanting to build a new motor so i'd like to check your 383 out

 

So should I stick with this cam and just try to tune it a little better and drive it a little better? I was thinking of pulling the heads and adding the slimmer head gasket to give a little more compression. My true goal at the track with this car is to dip into the high 11s natuarally asperated. I know that is posible but I like the high moh (at least 115) to go along with the E.T.

Right now a rollbar is really out of the question as the wife would throw a major fit (she gets her thrills driving it occationally).
Is the car running bad or do you guys think it is just s little low for the combo or OK?

 

Zac I'm not sure yet if I'll be able to break away sat eve. My 5 year old has a wrestling tournament and it may take all day if he does good...lol