cmashark

what's this 1500 DA?

formul89

My '89 Formula 350 weighed in at 3,350 with half tank of gas and no driver. It was pretty light as far as f-bodies go.

The intake tube angle plays a small part, but the Corvette should always be a step ahead stock anyways. Can't have the ponies outrun the thoroughbreds!

8388

A blower

cv67

OK, Mic help me out here. Wev'e pm'ed before. 89 A4, 3.07.Stock except for some porting to the runners, plenum, base and a 2.5"exhaust w/Delta Flos. K&N, power coupler,160 stat, bypass, airfoil. Massaged the T.B.no frisbee -Before mods, 15.0 @89.9mph(2.24 60'):after mods 14.80@92.4(2.0 60')These were made at LACR (2700 ft) 70ish degree weather, 160ish temp. Small burnout, no detectable wheelspin. Left it in drive. Left from about 900 rpm:any more pushes it through the lights. I know elevation hurts (a friend w/a Crossfire runs side by side every time-He ran identical times at this track. At Bakersfield which is 800 ft he dropped to 14.3), but what am I doing wrong? 8 degrees timing, new 24lb Bosch, hi flo cats---I'm stumped!!!

Edit:had a compressionand leakdown check done. No issues or low pressure. 0No 7 was 10%less. Big deal

kopbet89c4

I thought descreening the MAF and advancing the timing from 6 to 9 degrees really helped me so far! I never knew it would help me take almost tenth off my best ET and increase the trap by about 1.5 mph.

Mad-Mic

i would check your plugs and fuel pressure. remember though, for every 1000 DA is 1 tenth and 1 mph.

there is no set parameters i could tell you that will open your car up. i can't just say copy mine. 12 degree timing, 45 psi fuel pressure, (stock pressure regulator btw) 18.5 psi in the rear tires, .047 on plug gap with this plug only. i wish i could. thats when you need to do small adjustments here and there and if it don't work turn it back to where it was. timing is critical. timing is critical in these cars due to the computer. 2 degrees either way from max setting and it falls off noticably. i never had to play with fuel pressure due to it holding at 45 psi on the stock regulator. AF Ratio at the dyno pulled 12.9:1. right where i wanted it.

one thing i continually do is keep my car in the best tune as possible. i change the plugs twice a year need it or not. check the wires and change if necessary. change cap and rotor every plug change.

playing with launches. taching the rpm's up as much as possible for maximum launch. knowing how to roll slowly on the gas pedal if it's a slick track instead of stab and jab racing. playing with air pressure here helps alot.


run in the coldest air you can! this equals lower DA and quicker times another thing i do is completely cool the car down with ice on the intake. the idea is launch at 130-140 water temp. this is good for 20-30 rwhp. compared to 200+. shifts are much harder also

takes alot of seat time. if you only goto the track once a year then by the time you end up going back your tune up is shot. might have a burnt wire, plugs might be gunky black from a rich setup, and thats why your running slower times. it's hard to pinpoint it behind a computer screen

keep playing with it

kopbet89c4

I was pinging or "pung" once at 10 and even more so at 12. What did you do so your L98 didn't ping at that time? I know I always run 93, but its scary when you can hear those noises after you advance it like that! 9 does it for me so far...

cv67

I hear ya...
All tune up parts, sensors are new. MSD coil, wires, rapidfires @.40, fuel pressure I haven't checked in awhile. Car does crank for awhile before catching, come to think of it. Always has. Didnt' want to put in AFPR yet as I put 24lb injectors in. As soon as I get a slight exhaust leak (broke a stud off on the manifold) fixed, I can dyno it. Are you manually shifting? If I leave it in "D" it shifts just as the power falls flat...Tire pressure was about 22 lbs.

Mad-Mic

1st to 2nd 4900 2nd to 3rd 5100

Mad-Mic

that i can not explain.....lol some cars i've read like -2 degrees some like +12 degrees or more such as mine.

cv67

I dont' even know if mine will rev that high I'll try loading it up more and manually shifting next time

hippy

When my car was on the dyno it didn't do sht to move the timing any which way. I tried 6, 8 and 10 no difference.
I ran 13.1 at 105 with the stock cam and heads. I sure wish I would've invested my intake money at the time on a vigilante instead as that 13.1 would've been in the 12's as my 60' was a blistering 2.01.

Vic'89

DA is a measure of the air. The colder and more dense air is better for ET's.
For every 1000', my Vette runs +- .10 in ET.

At 2000 DA, I am running about 12.75 , at 0 DA I run about 12.55.

Also , another very important factor in maximizing ET's is to have the coolant temp at 160 degs. On occasion, I have run at 190 - 200 degs coolant, and My ET's go 2 tenths higher.

Vic

formul89

If these are the Delco Rapidfires and you regapped them, take them out. I always ran Bosch Platinum for years with zero problems and the car always ran best with them. I tried the Rapidfires and had nothing but rapid-miss-fires.

Mad-Mic

Bosch platinums are junk. after 6k in miles they are done.

i'll keep my AC Delco Rapid Fires any day over Bosch junk

hippy

Please don't tell that to my Bosch platinums that I've had in my car for the last 4 years and 25000 miles.

bigcityvette

Cold air intake or k&n with cut air filter lid, modified maf, 58 mm throttle body, t/b coolant bypass, LPE Super Ram intake and manifold, clean injectors or replace with ford svo 24 lb injectors, adjustable fuel pressure regulator, under drive ASP crank pulley, update cap, rotor, coil, wires, plugs, 1.6 rocker arms, hooker 2149 headers coated 1 3/4" then a front y pipe and a corsa cat back exhaust with a high flow random tech cat converter and a computer chip to top it off.

ZBrink

Wow...you guys went so wild with my little thread here that its taken me 20 min to go through all of the information. I think I have some good ideas now but I will of course take any more good ones. Thanks for all of your input and help!

Vic'89

First thing, make sure your car is in GOOD tune.

Do you have any baseline numbers ? ET's or Dyno ?

Vic

game on

Do not waste too much money on bolt ons.

My opinon, cool the engine down with a new chip, fans on sooner, some timing changes. Cost you around $350-400 to do this.

Waste of money with other aftermarket parts. Power comes from the heads/cam. Exhaust without heads/cam, little or no difference in the seat of the pants feel.