First time track results

[ponchopwr70]

Well I went to the dragstrip for the first time last night. What alot of fun that was. I borrowed a set of bfg drag radials 235/60/15 on corvette wheels, they didn't hook to well. My first pass I went 105 at 13.01. my fastest time was 12.95 at 105. The car was pretty consistant 13sec and 105.It would smoke the tires off the line and when i catch second it would chirp. I still need some practice and better tires, here is how my best time slip goes

R/T .301
60' 1.978
330 5.446
1/8 8.321
MPH 85.30
1000 10.825
1/4 12.955
MPH 105.46

I don't know what the car weighs has to be around 3700 with me maybe more. has a 26" tire 3.55 gears th350 2400stall 388chevy 10.8:1. Let me know what you guys think. I should do better with a 275/50/15 m/t drag radial, but i can't afford rear rims and tires right now. I'm just happy a finally got to go to the strip.

[BA.]

I'd think that was unsuspectingly fast for a Lemans. (in a good way) Overall, that's a good run!

I'd bet that it weighs more than 3700 with you in it though.
Depending upon your weight and whether you have alum. heads on the motor, you could easily be at 3900 with you in it.

[ponchopwr70]

I weigh 190lb, my engine is iron block iron head sb chevy. I have all steel body panels,huge iron front bumper, the chassis is also boxed, (I know that added some weight.) I wish the scale was open last night that would've helped a lot. So I guess I did for a street car.

[69boo307]

considering your engine, I think you're leaving some on the table and could use a bit of tuning. I run about the same or a little faster with less compression and cubes (357, 10.6:1), but otherwise almost the same weight and specs.

[ponchopwr70]

69boo307 thanks for responding, I've always liked that car it looks nice, your cam is bigger than mine i have 235 @50 507lift and 108 lobe seperation. You also have a higher stall too. How do you like the m/t drag radials? I'm debating on getting a set for my 17's or just buy some 15's with drag radials. My timing and carb could be holding me back to. I have 13 intial and 33 total (anymore and it will ping) my car is a holley 750 vacuum sec. with 73 jets in front and 80 jets in back with the weakest spring in the secondaries. Thanks.

[vcho455]

Your Lemans will weigh in closer to 4000 than 3700. My 69 GTO weighs 3780 with me in it. 1970 was the first year of the door bars and the larger bumpers. You'll lose about 50lbs due to the cheby. Your 60 ft times are high. Get some of the TA performance No Hop traction bars. Set them up with proper pinon angle, and you can get your 60 fts down into the 1.7,s on your 235 slicks. That should put you well into the 12.70's. Our 64 GTO does with Les Schuab 255-60 15's. Great fun to pull up to the pro lanes with the street tires and blow some people away.

[ponchopwr70]

Thanks vcho455, I borrowed the 235's from a friend so I'm going to buy my own set next year. I might get 275/40 m/t drag radials for my 17's or buy a set of wheels with 275/50/15 m/t. I'm going to look into those no hop bars. Last weekend I went to the track and ran 12.98 at 106 with 1.99 60ft time on nitto 285/40 street tires. Here are some pics of the launch.

[ponchopwr70]

I weighed my car this week end at the gravel bank. The car weighs 3500 without me and I'm close to 200 so race weight would be 3700lbs

[ponchopwr70]

Took my car to the dyno friday. My first and second runs were the same and my third was higher due to the fact we let everything cool down. For some reason the third run didn't graph right though. So my first run I have a graph and the corrected numbers are 318hp and 315tq at the wheels. My numbers where higher uncorrected though. On the third run I saw the screen and it said 328hp and 345tq(uncorrected). All in all i thought these numbers sound low. What do you guys think? My engine info is on my ptgarage page.

[BA.]

The two mysteries here are the head spec's and timing specs. (and whether it's curved well)

What kind of numbers were you thinking of? 350hp? 375?? I dont' think you're too far off unless those are some kick ass heads. 350 at the wheels seems attainable to me with a real good tune. Of course, I'm just speculating.

[ponchopwr70]

The heads are new castings of the old camel hump heads. They are 2.02intake and 1.60exhaust. The chambers are now 68cc's. I don't know what they flow or runner size. They have been ported quite a bit and everything is polished. The exhaust bends in the heads were made more gradual. But these heads are still 30 year old tech. I'm sure there are way better heads now. My timing is 14 intial and 34 total all in at around 2800 I belive. Also my air fuel ratio was at 12.7:1 the whole time. I guess its reality setting in I was just expecting 350-375 hp. My power curve was pretty good though. I will try to scan it in this week. Anything you guys think I can do to make more power besides the obvious new heads?

[ponchopwr70]

Heres a pic of the exhaust ports

I think my next step is to tap into the exhaust and see how restrictive it is. I really don't want to spend alot to get more hp but I still want to see if I can free some up. Any ideas?

[ponchopwr70]

Here's my dyno sheet.

[BA.]

I used to have several sets of the old Double Hump heads. 461, 461x, 462 and uhhh 962 or something.

Anyhoo, I recall reading in a magazine back then and the port sizes were in the 155cc - 170cc range.
Great for mid-range, or small cubes and higher RPM's, but maybe a little lacking for the 388 and cam.

Oh, I just checked out your times again, and that 60' is just a little soft. Not sure if it's a traction issue or the weight and 3.55 gears.

[ponchopwr70]

Well I have some upgrades I've been contemplating to get my car faster in the 1/4. I was wondering if any of these sound like they would be worth it or if I should just save my money. I want the car to still have good manners on the street. My list goes as follows-

1. 1.65 roller rockers (I have 1.5 rollers now) $210
2. 1 3/4 headers (I have 1 5/8 now) $550
3. Better exhaust (crushed and bad bends, proberly make my own, going to do this anyway)$200-$550
4. 3000 converter (2400 now) $400
5. Drag radials with 15's or 16's to fit over new brakes $500

Or should I just leave well enough alone because I'm also getting brakes and some suspension pieces, and still need a paint job. If I made these changes what would I expect?

[DJ Mabe]

Stall convertor and DR's are gonna get you your best improvement in the 1/4. If you are changing the stall, I would go higher than 3k. You'll need at least 3500 to get that car out of the hole like you want it too. Do the rockers, headers and exhaust at a later time. Those three combined will not help as much as a stall and tires will. WIth the stall and tires, I would expect 3tenths or more improvement.

[streetk14]

Well I have some upgrades I've been contemplating to get my car faster in the 1/4. I was wondering if any of these sound like they would be worth it or if I should just save my money. I want the car to still have good manners on the street. My list goes as follows-

1. 1.65 roller rockers (I have 1.5 rollers now) $210
2. 1 3/4 headers (I have 1 5/8 now) $550
3. Better exhaust (crushed and bad bends, proberly make my own, going to do this anyway)$200-$550
4. 3000 converter (2400 now) $400
5. Drag radials with 15's or 16's to fit over new brakes $500

Or should I just leave well enough alone because I'm also getting brakes and some suspension pieces, and still need a paint job. If I made these changes what would I expect?

If you are looking for the best dragstrip numbers, I would go with a 15" drag radial, or even better, an E/T Street style tire. They will hook better than a drag radial, and are DOT approved. They are not a very good tire for much street driving, but then again neither is a drag radial.

I think the 3000 stall would be a good choice, and will help your 60' times. The stall and some slicks will be a great improvement.

The exhaust sounds like a good idea, especially if yours has excessive kinks in it. Do a 2.5" system with a good crossover (x-pipes tend to make a little more power) and some good mufflers.

I would not go with the larger headers for your current engine. The 1 5/8" headers on the car are more than adequate for your 350-375 hp.

I also would not recommend changing the rocker arms. Changing the rocker ratio will really only help if your engine is under-cammed. I think your heads are probably the chork in the system, not the cam.

I think the rockers and headers would be a good upgrade AFTER you add a good set of aftermarket heads that can support the flow. At this point, you would be wasting money IMO.

Hope this helps,
Andy

[ponchopwr70]

Thanks for the input guys. I kinda had a feeling my heads were holding me back a little, These heads were ported alot by my engine builder. But there proberly is more to heads than just porting and polishing. For exhaust I was thinking of running 3" to 2.5" x to my flowmaster 40's 2.5" to flowmaster tails 2.5". I already have the mufflers on my car. Thanks again, any other suggestions?

[streetk14]

Thanks for the input guys. I kinda had a feeling my heads were holding me back a little, These heads were ported alot by my engine builder. But there proberly is more to heads than just porting and polishing. For exhaust I was thinking of running 3" to 2.5" x to my flowmaster 40's 2.5" to flowmaster tails 2.5". I already have the mufflers on my car. Thanks again, any other suggestions?

Your exhaust idea sounds fine. As far as head porting goes, more is not always better. You can do more harm than good with a poor port job. It would be interesting to see some flow bench numbers for your heads, but as you said, you don't have any.

I've always been into proven parts. That's why I am willing to drop the money needed to pick up a good set of CNC ported, flow bench tested heads. You know what your getting, and what they will be capable of. They do cost $$$, but are the best money you can spend on your engine IMO. If you are on a budget, you might be able to pick up a nice used set of heads for a good price. I've always been an AFR fan, but others may have their own opinion of what's best. Let us know how the project goes.

Andy

[ponchopwr70]

Well I made it back to the track on Friday. I have an all new best. I ran 12.64 at 107 with an 1.86 60ft. I ran in street trim with 285/40-17 nittos. The only changes I made were 3000 stall from neal chance that foot brakes at 2800 and flashes to 3500 and 1-3/4 headers with 3" x-pipe exhaust. I still need drag radials. I did change my springs and brakes earlier this year but I don't think they made a difference.