I igure as well also, but am changing rear gears any ways and have the 3.7's already. Im going to take the jet kit and a few bowl gaskets so that I can tinker with that as well. Befor I had the 4 hole spacer I had a 1/2'' open which didn't seem as crisp on the bottom end but did seem to have more top end that the 4 hole, so this makes me wonder what effects the 1'' open would have.

 

Congrats on those numbers. 12.75 on street tires shows a lot of potential. I saw your PM but we can talk about that here. From my experience, on drag radials, going from 3.08 to 3.73 gears took 5 tenths off my ET. Like Amorget said, reducing 60 ft times by a given amount will lower your ET by twice that amount. I would think the gears and drag radials would get you to a 1.80 short time. That should get you into the 12.30s. 107 mph is enough for a 12.3 ET.
What was the DA when you ran? You can search for it on Dragtimes.com.

 

Were you at Alaska Raceway Park? I just checked the DA there Sunday at 3PM (just to pick a time) was 28. That's pretty low (low is good). Last time I raced, May 17, the DA was 1,000. It will affect your numbers, so you should keep track of it.

 

Thanks. It's Alaska race park, I will track the altitude density, if you don't mind a little elaboration on da to help me understand what I'm looking at. I was working up to a better launch, not trying to spin the tires, which after the second run I figured I could have revved it higher( I'm happy for 2nd ever run). I figure you'd want to be on the verge of spinning but not spin. Id also like to try jetting up and down for the best mile an hour( I know my carb is not set up ideal yet). I also think with some practice my etc would be better. I've got both a blower(mp122) and also a custom cam from Straub(non blower cam) that I can add later on, I'd like to hit 11.99 or better naturally aspirated. My plan is to get the best et I can with the 3.7's and the current cam, then maybe switch to straub cam to see if it picks up any time( would be an interesting comparison). After that if I can get traction maybe try the blower. It was definitely fun. How much does the density affect you? Say from 28 to 1000? Did you pick up any mph with the gear change?

 

A DA change from 28 to 1,000 would probably add .15 to my ET. Overall, in Jersey, we see -1,000 to 2,000. Over that range of 3,000 DA units, my ET will vary 4 tenths with no changes to the car except running very thin secondary metering rods in the -1,000 conditions to richen the secondaries.
With a goal of 11.99 you've got to put drag radials on there. Put a line lock in too so you can heat them consistently. I have a 3,000 stall converter in mine. Eventually you might want to try that.
You have an interesting plan with the Straub cam and the blower, separately. I will definitely be interested in your results.
3.08 to 3.73 maybe added 1 mph for my car.

 

When I was ordering parts, I wanted in the 10 to 1 compression ratio range, I found it to be cheaper to order a short bolck with the shipping charges on each individual part versus the shipping on the short block plus the parts assembled were right around the same as I could buy them individually(actually save $600 buying the short block). I coppied a build that afr had on their web site shooting for 500 horse except using a 400'' instead of a 383'', except I wanted the compression a little higher than the 9.5 to 1. I bought the short block from cnc-motorsports and thier web sit said 10 to one, but when I got it, the pistons checked out with more cc's which put the compression at 9.2 to 1. I didn't sweat it as there was another build on afr's web site that was in the same power range with 9.2 to 1 making 500 horse with a little smaller camshaft. I had already purchased the camshaft from comp and decided to run it any ways which put my dcr pretty low @ like 7.3 and as a result I figured the low end would suffer some, it will still roast the tires, and after the stall converter theft(long story) and actually getting the 2400 rpm stall in that I'd bought the bottom end was tons better, add the fact that I'm going with the 3.7's it should have plenty of low end. about 15 months ago I talked to chris and he spec'd me a cam that he believes will make more power with more low end torque so I bought the cam shaft. Last June I was on my way back from Wasilla and was approached by a zl-1 camaro on the high way who wanted to race, so from 70 mph we got after it and he slowly but surely pulled away rightly so with more power and better gearing he should. So I got home and started the usual Ipa desert, well about 5 or so beers away and dicking around on ebay I was looking at blowers and superchargers. Well maybe it was 9 or 10 beers away, cause I sure didn't remeber bidding but woke up the next day to an email that congradulating me on my victory in the auction on the mp122. So my plan was to squeeze the best time I could out of the current combo and with gears, tires practice and tuning I think that I can atleast hit low twelves, maybe my carb is spot on, maybe better but the only way to know is to try. Then I have the custom cam by Chris and if things play out right I'd like to run it after I've squeezed every thing out of the current combo just as a comparison and if I can find the time, maybe this summer, but if I don't get the chance then this winter it will be a toss up as to weather I go with the blower or the custom cam. I've pretty much tapped the car fund out with fixing the damaged fender, replacing both the front and rear bumper and replacing the rear diff, and the car weither it be with the blower or with the engine naturally aspirated needs larger headers, plus with blower, i'd need to buy a different camshaft, distributor and boost gauge. gkull has me convinced that I could retard the camshaft and try the blower, plus the blower is hinged on weather or not I can get traction naturally aspirated with the 3.7's and wide tires. Sorry for the long story.

First time on the strip with your vette what did you turn?

 

Very first pass was 13.98 at about 97 mph. Differences now vs then(best pass 12.15 at 110):

headers & Magnaflows vs manifolds & stock type mufflers
ported Vortec heads vs unported
225/232 .510/.550 roller vs 218/224 .469 flat tappet
RPM Air Gap vs Performer
3.73 vs 3.08
3,000 stall vs 2,500 stall
drag radials vs street tires
Approx 100 lb weight reduction (spare tire, all A/C equip, etc.)

 

Had you raced before? That's quite an improvement. Who ported the vortecs and what did they flow?

 

I raced a lot years ago, 70s to early 80s. At that point I was bracket racing a 69 Camaro with a 427 and powerglide, on 10.5 inch slicks, running 10.70s at 127. That was fast for 1982. Then I stopped for 25 years while my kids grew up.
As for the porting, a guy at a small shop in Virginia did them. Flow data only showed about 20cfm increases but it took about 2 tenths off the ET.
All the other work in my Vortecs (cutting valve guide bosses, screw in studs, opening up for 1.6 rockers (not using them now), surfacing, 3 angle valve job) I got done for free at my brother in law's shop. So I didn't mind the $700 for porting.

 

For sure, sounds like they work well. I look forward to going next time off work.

 

For me, next time to the track, don't worry about your carb. Hot lap it if you can and get as many runs in as you can. Until you can put down a consistant time I think track time is more important then messing with your carb. Once you are able to run within a couple tenths and 1 or so mph then start messing with the carb. That is how you'll be able to tell if you are making an actual improvement or not the best.

 

I figured getting a consistent run was the priority, I thought along the same lines if you can't produce the same numbers then you can't improve.

 

You here any thing about t tops needing a 6point cage at 13.49 or faster? When I went through tech, the inspector said that and that they'd kick me off the track if I ran faster.

 

You need a helmet at 13.99 and faster. Don't need a cage until 10.99 but you do need a bar at 11.49

That is at least if they are following NHRA rules. The track can say whatever they want.

 

This is ihra.

 

Looks like they might need to update their rule book, according to this thread the requirement for t-top cars at 13.49 was removed in 2005:

http://www.thirdgen.org/techboard/or...lbar-cage.html

The person who posted those rules is a very respected drag racer on Thirdgen.org I doubt the IHRA has added back in the requirement.

Here is the IHRA rule book. I did a search for t-top and found nothing interesting

http://www.bluetoad.com/publication/?i=186944&p=1

You *might* want to consider buying an IHRA rule book and bringing it to the track with you. If they complain ask them to show you the rule. Bet they won't be able to find it.

 

I only have experience at NHRA tracks where T top cars are considered hard tops and therefore the bar requirement starts at 11.49. Also, convertibles with the removeable hard top are considered hard top cars and don't need a bar till 11.49.

 

awesome idea, I will do that. Like I said the tech inspecter told me that and also told me that The tech inspecters on the track would pull me off if I ran any thing faster than 13.49, but they didn't.

 

I turned a 12.64 at 107.77 today on one pass and a 12.66 at 108.88 on the second pass there was a third pass that I missed second on. I left at little higher rpm than the last time when I turned a 12.75. The only changes I made was traded the t Stat to a 160, added 2 degrees timing and installed a shift light/tach since my factory tach went out, light came on at 5900 and didn't check the rpm in which I actually shifted. I left at 1300 rpm on the 108.88 MPh. The D a I calculated at 172 feet. I don't think that's too bad for driving 50 miles on 87 octane running a 2400 rpm stall and 3.08 gears all on skinny street tire. What do you think?

 

If you were on drag radials today you would have gone 12.2s. That means 11 sec potential in cooler air. Get those tires.
I was racing today and my best time was 12.44 at only 102 because I was on the brakes and lost since I was dialed 12.45. I was running 107 mph on earlier runs.
Congrats on those new bests.
BTW. The DA here was 1900.