How do I get into the 13's at the track?

[87blackroxi]

I went to the track last thursday and ran 14.2 in the 1/4 mile. Which I was very happy with. But now I have the itch to get into the 13's!
What would be some mods to consider under $300?
So far I have done:
headers, true duals , magnaflows, vortex ram air, new spark plugs, msd ignition wires, new distributor cap and rotor.
I ordered an msd ignition coil and am going to do the TB bypass. So what else can I do that will help me at the track?

 

[Edmond]

How about eliminating the spare tire and cutting down the PSI on the tires?

 

[C4Tom]

Here are some things to consider:

1. Traction? Tire slippage can slow you down at least a .1 of a second. Tire pressure is critical. You can lower the pressure to gain better traction for launch but, it will actually slow you down at the big end from friction. Play with pressures during multiple runs to see what works best.

2. Air Quality? Hot, humid days can easily add a .10 of a second. High engine temps will slow the car because it heats the incoming air and the cylinder temps are higher, not good. Have you noticed that your Vette is more of a screamer on cool, dry mornings and doggier when it's hot and humid?

3. Shift Points? Auto or Manual? Not sure of your drag racing skills and how good you are at 'reading' the engine. Perhaps raising or lowering your shift points will make your Vette quicker. A good racer can hear/feel the motor... knowing when the HP/Torque is going to peak and react to it.

4. Redline? Some new racers tend to run it up to or near the redline to shift. Most engines will run out or fall over peak HP/Torque long before the redline. Save the redline for testing top speed on the salt flats.

5. MPH? This can tell you about your gearing and where you are making horsepower... not torque. Not much you can do about it for under $300 though.

6. Fuel? What gas/octane were you using? Use the highest octane rating you can find. Make sure that you use an injector cleaner to clean the injectors and the valves. Perhaps use an octane booster. This will keep the knock sensor from backing off the timing and killing the torque when you leave. Of course, this will only help as long as traction isn't a problem.

Hope this helps and most of these are pennies to help.

 

[rrubel]

Underdrive pulleys and an AIR pump eliminator... and drag radials for a good start.
[RICHR]

 

[vetteboy86]

What was your trap speed? I cant believe that the car wouldn't run faster then that with those mods.

 

[Vettefan87]

I think it was around 94 mph... He hasn't said if it was really humid or not down there when he ran. That makes a big difference. You can also descreen your MAF, advance your timing, cut back the electrode on your sparkplugs, and definetly run about 22 lbs in your rear tires.

 

[Edmond]

Isn't it always humid in FL?:L:L:L

 

[87blackroxi]

I did put ther rear tires down to 20 lbs. I Didn't think of removing the spare tire though. Good idea! probably takes some weight off. less weight=faster!

I ran 93 octane with a can of octane booster thrown in. I almost ran out of gas by the time i got to the track so I put 1 gallon of 100 octane in from the track.
Next time I might go for the 112 octane. I was unsure if the old lady could take it being 18 years old and all.

The wheel spin wasn't bad. a little bit more on my second run that my first. but not bad at all.

And the humidity was horrible. It is Florida after all. It was about 83 degrees at 9:00 pm and the humidity was up there so that didn't help at all.

Trap speed was 94pmh. So I am assuming that is about normal?

So what do you think I should do next for the car?

 

[AdvancedAutoCC]

Traction is key and cover the basics...

Get a QUALITY timing light (dialback type) and advance the timing in 2 degree increments until it pings, then back it off 2 degrees. Then buy a set of drag radials and have at it. As far as going further...changing the rear axle ratio would be #1 on my list (but remember you still only have a Dana 36). A car with a mediorce engine and proper gearing will beat a car with more engine and the wrong gearing 95% of the time (I speak from experience). Descreening a MAF on a street car is not a good idea IMO, and the gains will be negligible on a street car.

DO NOT run your fuel low to "save weight".... run at least 1/2 tank to avoid uncovering the fuel pump pickup and causing a lean condition. Also, leaded race fuel does NOT belong in a car with an oxygen sensor (unless you like replacing them often). Use unleaded race fuel instead (100 octane usually available at the track).

$300 won't buy you anything except a timing light at this point.

 

[87blackroxi]

Get a QUALITY timing light (dialback type) and advance the timing in 2 degree increments until it pings, then back it off 2 degrees. Then buy a set of drag radials and have at it. As far as going further...changing the rear axle ratio would be #1 on my list (but remember you still only have a Dana 36). A car with a mediorce engine and proper gearing will beat a car with more engine and the wrong gearing 95% of the time (I speak from experience). Descreening a MAF on a street car is not a good idea IMO, and the gains will be negligible on a street car.

The MAF is a topic I've heard tossed around alot. Some say it makes no difference some say it makes a few hp. So I am still unsure of it.

Gears was something I had considered but would come in a little while once I can free up some cash. But what would be a good ratio to go with? Considering It's primarily a street car that sees the track once in a while. Something like 3.33's?

And how much does a decent timing light go for?

 

[vetteboy86]

You dont have to spend a fortune on the timing light. I know how to set the timing on my Trans Am. Unplug the vacuum line, and have at it. Not exactly sure what the right procedure would be with our car. I know you unplug the EST wire. Would you set the maximum advance to come in around 3000 RPM's and then whatever it falls back to at idle live with it. You would have to do this with the a timing light that has a dial on the back. Some say they set the timing at idle. I am not really sure. I think I bought mine for around 40 bucks at a discount outlet type store.

As fas as descreening the MAF, I dont see how it could be bad, but also do not see how it could improve performance. Just have to go with your gut on that one.

With the gears you really have to choose the right ones. You want a gear that will keep your car in the powerband. Going to high, will rev the motor too quickly, and we know what happens then to the L98. Something conservative, but not too high. I think 3:73's might even be to high for a somewhat stock L98. I could be wrong though. I am not sure what you can get with the D36, I have never really checked into that. I need to start though

 

[87blackroxi]

I think it was around 94 mph... He hasn't said if it was really humid or not down there when he ran. That makes a big difference. You can also descreen your MAF, advance your timing, cut back the electrode on your sparkplugs, and definetly run about 22 lbs in your rear tires.

That was something else i was wondering about. I was under the impression you had to buy cut back plugs. I didn'y know you could cut them yourself. If you have done it, How? What did you use for cutting/ Like a dremel?

 

[87blackroxi]

Underdrive pulleys and an AIR pump eliminator... and drag radials for a good start.
[RICHR]

Something like this?
http://www.madvet.com/shop?frame=3.141.842

I was looking at this wondering how easy it is to remove the air pump. I'm sure the removal process is easy but would it throw any codes or is there anything else that needs to be done?

 

[Vettefan87]

Yup, thats it.

What were you shifting at, or did you just leave it in OD. You should leave it in 1 and shift when the tach reads about 4900 RPM's.

 

[87blackroxi]

Yup, thats it.

What were you shifting at, or did you just leave it in OD. You should leave it in 1 and shift when the tach reads about 4900 RPM's.

Just left it in d and went. I was concentrating on not crashing :L

 

[AdvancedAutoCC]

Spend your $$$ on a pair of drag radials first, Shane. Anything else is going to cost real $$$ to accomplish at this stage of the game, and an air pump eliminator isn't going to make squat for HP, it's designed to clean up the engine compartment. You've already done most of what you can do with the car without spending (relatively) a lot of money. Your main problem is lack of traction and you need to address that first. You said in your previous post that it spun a little worse on the second run. Remember, we're talking about 2 tenths of a second here.. an eternity for a Pro Stocker, but not for your 14 second streeter. Get rid of the spin, and you'll likely pick up at least 5 hundredths on the short time. A general rule of thumb is for every .01 you pick up on the 60 foot, you'll double at the top end, so there's at least a tenth you're losing by wheelspin.

As with descreening the MAF, cutting back sparkplugs is another thing that's hotly debated. I would see the advantage of cutting back your plugs ONLY if you're running an aftermarket spark box (MSD, etc), but that's my own personal opinion (based on 20+ years of drag racing), so take it as you will. T

For a timing light, go to your local Sears (or Sears Essentials) and buy a decent Craftsman light. Should cost around $100 for a dialback. Set timing at idle only (there is no mechanical or vacuum advance to deal with).

FYI about gears.... a long time ago, I had a nearly stock '79 Trans Am with the smogger Olds 403 engine in it. I took it to the track bone stock and it ran 15.90's with only a "test pipe" in place, dead hooked. I changed gears from 2.41 to 3.73 and it immediately ran 15.10 spinning the tires pretty badly. With a set of old worn out oval track tires (couldn't afford slicks at the time), it dropped into the 14.80 range. I added headers and a Holley spreadbore carb and it ran in the 14.50 range (only picking up about 3 tenths). The gears made the most dramatic difference (over a full second in ET reduction). I beat a lot of people with "built" engines in street races, simply because they took the backwards approach to building...spending all their $$$ in the engine compartment while leaving pegleg gears in the back. Save your money for gears... you won't be sorry. For a ratio, I'd use a 3.54 or 3.73. Gears aren't glamorous, but they work.

 

[DRTH VTR]

Spend your $$$ on a pair of drag radials first, Shane.

I absolutely agree with this. I would bet that drag radials would drop you that 0.2 seconds that you want. When I added drag radials to my Z06, it resulted in a gain of at least 0.4 seconds. No lie.

Between a VaraRam and drag radials, I gained 0.6 seconds and 4MPH.

 

[87blackroxi]

Spend your $$$ on a pair of drag radials first

Save your money for gears... you won't be sorry. For a ratio, I'd use a 3.54 or 3.73. Gears aren't glamorous, but they work.

Good info. Makes sense.


But my concern is it's a daily driver. Would 3.54's be ok for daily use? Like on the highway, would I just have higher rpm's? And last Q is what is the average price for the gear swap?
Thanks

 

[Legion21]

87blackroxi, what track did you race at? I'm just curious because I'm waiting for the temperature to drop a little and will be going to Bradenton to get some baselines before I do my Head/Cam. I'm thinking I might go up there in September.


Greg

 

[bobby1]

Do all the above or buy a z06 and go directely into the 12s.