So I got my Vortec heads installed, along with the SDPC TPI base and Edelbrock Shorty headers yesterday.

Stock runners and plenum and a not so great YPipe.

I have been doing alot of datalogging with the Moates software and it dawned on me this morning that I can compare a couple of WOT passes and calculate the amount of time to accelerate from X mph to Y mph.

Here is the breakdown:

'89 GTA 350/700R4, 24Lb injectors, K&N, Cat removed, ARAP Bin.
Accelerated from 51.1 MPH to 91.1 MPH in 9.7734 seconds. This was during a 1/4 run which resulted in a 14.7@93MPH

Same car with CatBack, Vortec Heads, Vortec TPI Base, Headers.
Accelerated from 51.1 MPH to 91.1 MPH in 8.5097 seconds. This was on the road last night coming back from the shop that installed the heads. I have a small exhaust leak and still needs to be tuned.

That's a difference of 1.26+ seconds...

What do you guys think of this? Is it accurate? Anyone use this method to determine gains and then prove them? I will probably be heading out to an 1/8 mile track on Friday and if I can I will head out to a 1/4 mile on Saturday but I was psyched by these numbers...

What do you all think?

 

A lot of the general accelleration times vs. speed depend on the road driven. If you drive the same road several times before and after a mod, make temperature and atmospheric pressure notes, average the runs, then compare with like runs from before and after, then you'll get a real idea of the gains you've gotten from your mods.

That being said, unless you were going down a hill the second time, 1.26 seconds is quite a gain on a moving run!!! Now, if your gears/trans/cam/intake are all set up together, and can still get off of the line equally to your previous runs, you should see a nice drop in ET. Good luck.

 

Yeah I realize that this is not the most accurate method of determining gains, but as I was looking over my data logs it just dawned on me. I did the calculations for fun.

The weather was different, no doubt, but like you said 1.26 second difference at those speeds is quite significant.

Either way I will be heading to the track in the very near futur to time it.

This just got me psyched is all...hopefully not for nothing!

The road was flat. On a side note.

My brother has just built and installed a pretty stout vortec headed 350. He booted it behind me and I could no longer pull on him. If we went long enough I beleive he would have started catching and eventually passing me but between 3500-5000 we went about even.

We estimate his car to run very low 13 and possibly high 12s so I was pretty pleased with that as well.

 

I'm sure there's a formula that someone could use to figure out your gain in the 1/4. Can't you do a 0-100mph run, that would be easier to guestimate with?

 

Moates software does that automatically for you. I will give it a try tonight. It has a 3 mph trigger and then it starts calculating elapsed time over distances.

It's pretty accurate, came within a 1/10 at the track.

The only problem is wheel spin.

I got the car back last night so I haven't had the time to do all this.

In the end, the track will be the true measure of performance. I am just psyched is all!