Well today was it. I got to the track at 10:00 this morning.I'm ready to try my new setup. I own A 95 Z28 Conv. M6 with 38k on the clock. Last year I decided to mod my car, No muffler and CAI. this was going to be the baddest car on wheels. To start with I bought a 383 short block w/ splayed caps topped it off with LT4 heads that flo 275I @ 550 and 185E @550 C.C. 305 Cam SLP 1 3/4 Shorties 30psi injs Mor CAI Stock 3.42 Gear.After the dyno tune the car made 346RWHP 354RWTQ. I was told that this would be enough power to run 108 to 112 MPH at the track. well after my first pass the car went 103 then 104,and 104 again. the tears started coming down at this point what did I do wrong. It seems to be a proven combo. the air temp was 60ish with very low humitity and no wind to speak of. Just a perfect day

R/T .627 .982
60' 2.565 2.370
330' 6.336 6.107
1/8 9.330 9.107
MPH 82.15 82.01
1000 11.89 11.663
1/4 14.063 13.82
MPH 103.75 104.28

These are two examples of two passes on 275/40/17 comp T/A 's not to be confused with D.R. 's...................Any Advise.....Joe

 

Well their might be more issues that tell the whole story.. In example my car at 3700lbs w/ 308rwhp trapped a best mph of 109.55 through a 9" w/ a avg of 108.7's or so.. i'm a 6 speed also so your power should have brought you to the tune of 113ish on a good weather day.. Now what is the altitude of the track? exact weather? baro? humidity? just because it don't "feel" humid don't mean the air is really there.. who tuned your car? whats your AFR? Any k.r? lots of ?'s you should be making more power than that especially being a 383.. What C.R are you?

 

what are you shifting at?

 

If you bring down that 60 ft it will definently help your times out. As well as bring your mph up. Less distance your spinning the more you will have to gain the mph.

Bring that 60ft down to atleast 1.8 and you should be close to 13.0...

Then again i just noticed in your times you need GEARS

Edit: your an A4 no converter

 

humm that is interesting, I ran a 13.50 @ 104 on my car with basically headers and 4.10's in hott FL air. Try some drag radials, only thing is that wont help your MPH.

 

did you get the car reprogrammed? you could be getting a lot of knock retard too. to be honest and im not trying to upset you more but guys with stock short blocks and the heads/cam combo you have are making as much power as you are. the cc305 is a really small cam for a 383.

 

Get some drag radials! When I tried to run on regular radials, my trap speeds would be 5 to 10 mph slower than with DR or ET streets, simply because I couldn't hook up through 1st and 2nd... Your best 60' is still almost 2.4 seconds! _LOTS_ of room for improvement there.

 

Something is definately not right to only make 346rwhp and trap what my car did with only shorties and a cai. I wouldn't be happy trapping even under 120 with a 383. But you do have a rather small cam in a 383.

 

fix the traction problem first. then see what it runs. I run 1.79 60ft 8.19@82mph 1/8 with stock heads/ cam/bottem end.

 

Illusional T/A : I don't live in Boise. I live in chicago so appx500 ft above sea level C.R. is 10.1 to 1. and i wanted a C.C. 305 Because it looked to be a good cam for a Blower later down the road. Also I shift the car at 6000RPM indicated.I do not Have a scanmaster. but the people that tuned the car used a wide band O2 and showed no knock w/93 octane. I most likely spun the tires at the gate as well as 2nd gear but not enought to hurt my MPH by 8-10 or so. it doesn't seem possible that a sticky set or tires will get me the 8-10MPH that I'm looking for but I'm sure it would help some..............Joe

 

What springs and rockers are you using?

 

Also the weighs 3800Lbs with me in it 1/3 tank of gas and some stereo stuff in the truck

 

You need to shift higher than 6k rpm with the cam, you need to find out where the cam makes the peak power on your dyno graph then shift 300-400 rpms after that so it stays more in the power band of the cam.

 

If I'm not mistaken Chevy 1.6 (Silver) and i told the builder to use the springs that go with the 305 Cam.....

 

One other thing about my passes. the car barely pulled fourth gear. It's like I could have finished in third. Now maybe a 4.10 would help to pull more rpm's on top but it would have hurt my 60' time. also somebody replied to my thread. saying they lost 5-10 MPH from D.R. s to street tires is it Possible to get that kind of gain if so I'll order tires this week............ joe