Just out of curiousity,how many of you guys would favor having great seat of the pants vs. actual ET gain..say you're running a double pumper carb..has great throttle response,and breaks the tires loose all over the place..basically runs good at the track too..but you put on a vacuum secondary carb,and while throttle response is still good,you obviously don't get that "kick" like a mechanical secondary carb does nor does it break the tires loose at speed like a double pumper would,in fact,you swear the car is slower with the vacuum carb,but at the track,the car ET's better (say .15)what would you do? Obviously,this question is more aimed at the hobbyist/enthusiast who might go to the track once in awhile,not someone thats very serious about ET reduction or getting the best performance.Same with gear too...a ride thats little overgeared,but fun to drive (say 4.10's)..and you find out you could be quicker w/less gear (say 3.73's or 3.55's) Would you give up ET gain for better seat of the pants..
Me personally,I'd take the vacuum carb or anything that proved it self faster..hell with seat of the pants :D

If seat of the pants seems better, but it ET's slower, then you need some recalibration. :D

Seriously, I understand what you are saying.

The best example I can give is I've driven 380 RWHP LS1's and new Mustang supercharged cobras. They don't seem fast, but they are. They are so smooth compared to an older car

Cars like my Nova have nowhere near the traction on the street with street tires and it is a lot more "fun" when I get on it than these new cars.


When I'm at the track all I care about is tuning it so that it goes .01 faster than it did before. On street tires my Nova is pretty much useless on the street and I just enjoy driving and don't mess around like I did 15 years ago when I was younger and dumber.

Originally posted by mr 4 speed:
hell with seat of the pants :D BS. Racing, or just driving, wouldn't be any fun if you couldn't feel it.

I wouldn't be satisfied unless I had a kick in the seat of the pants AND the faster ET. Make enough power to go around.

Tim.

Tim,when I say "hell with seat of the pants" the perfect example would be the double pumper vs. vacuum secondaries..I'll take the ET gain with the vacuum carb vs. the dp's better seat of the pants but a slightly slower ET..

In general I favor real ET gains, but there are some things I don't like. Loose torque converters, for example, improve ET but make your car a real slug on the street. If you are cruising along at 20-30mph with a 3000 stall and you nail the gas, all you get initially is mush...poor throttle response. Same with big cams. The only way to get the car to really move is wide open throttle.

Take a car like the new Honda sportscar for example, what is it called, S2000 or something? Supposedly they rev to 8500 and will ET around 14.0, but owners complained they were dogs unless you drove them in full race mode due to lack of torque. A good example of a car that ET's well but has poor throttle response on the street.

to me its seat of the pants. ive not been to the track yet but the goal is 11.50s. it may very well run that at some point but it still feels like a dog. Dave

Originally posted by Georgia69:
In general I favor real ET gains, but there are some things I don't like. Loose torque converters, for example, improve ET but make your car a real slug on the street. If you are cruising along at 20-30mph with a 3000 stall and you nail the gas, all you get initially is mush...poor throttle response. Same with big cams. The only way to get the car to really move is wide open throttle.Oh really? That's news to me...mine sure doesn't behave like that. Even with an 8" 5500 flash converter, when I stomp the throttle even at 50 mph, the front end rises up and the car responds right away.

Must be all those rect port head combinations that respond that way :rolleyes: :eek: :D tongue.gif .

To me the question is more to the point of what is your package. Auto, w/ full exhaust, 3:73's or less, converter in the 2500 - 3000 range, CI in the 400 - 454 range : vacuum carb all the way, just play with the secondary spring to get it opening as fast as possible without a bog. Stick car w/ big gears - another story. The initial hit of acceleration is good, but I like the pull of a broad RPM range. The one thing about the new cars/trucks is the way fuel injection units come on - smooth power all the way.

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Originally posted by Georgia69:
In general I favor real ET gains, but there are some things I don't like. Loose torque converters, for example, improve ET but make your car a real slug on the street. If you are cruising along at 20-30mph with a 3000 stall and you nail the gas, all you get initially is mush...poor throttle response. Same with big cams. The only way to get the car to really move is wide open throttle.
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Oh really? That's news to me...mine sure doesn't behave like that. Even with an 8" 5500 flash converter, when I stomp the throttle even at 50 mph, the front end rises up and the car responds right away.

Must be all those rect port head combinations that respond that way .
I tend to agree with Todd. My car's converter flashes to 4000. I don't care what speed it's at it just wants to go hard with no hesitation! Even going down the highway at 55 it's instant tire spin. 1st gear is basically useless on the street even with QTP's. Maybe a mismatched combo would be a dog, but with the right combination on the street I've never driven anything more fun than a car high stall converter. However, if ET reduction didn't feel as fast I'd have to go with ET reduction. Seat of the pants means nothing on the track!

Matt

We're drifting off topic here guys.

I'd take the ET gains over seat of the pants any day. Even an ET gain set up would have a decent seat of the pants feel and if you want bragging rights, nothing argues louder than an actual time slip.

And I have to qualify my statement by saying that I don't go to the track much nor will I do so more in the future, but my car's abilities are still measured by the timeslips. And when the wagon is done, by the time slips AND the slolum times..... :D

It's funny, I've already had this arguement with a friend concerning my who-knows-when-it-will-be-finished wagon: DP mechanical vs. vacuum secondaries. I say vacuum because it is more forgiving and adaptive to throttle position and load and my friend argues that he likes being in control of the secondaries and likes the feel of the "kick" they provide. Of course this all assumes you chose the right size carb of either style in the first place.

If I had a spare vacuum Holley the same size as my friend's DP, I'd let him try it to see if he could get into the 12's more consistantly!

Do what I do - run a 750 VS at the track, take it off when you get home and put on a 650DP!

Originally posted by 10secBu:
Must be all those rect port head combinations that respond that way :rolleyes: :eek: :D tongue.gif . smile.gif

Chris, i've been under the impression that the double pumper is quicker, generally.

I mean both carbs rely on the owners ability to tune, but thats the impression i've been given.

Maybe its ride specific.

For sure, generally when dealing with mild stall/high gearing, the slight delay of a vacuum-driven carb is good, to help keep the intake charge velocity up. Should 60' better unless you've spent hours tweaking a DP, on that type of application.

As to Chris's question, donnow. Old Red 'feels' like an 11 second ride. Sure would like the timeslips to prove it!

I'll take the E.T. please.

You can brag about that.

My 68 doesn't E.T. very well, but it feels like a roller coaster. Four speed 4.10 gears, and a rev happy 396.

Its fun, but it encorages you to misbehave, and I'm not that good at avoiding temptation. tongue.gif

My goal for the 72 is 12.0 in a car that from the outside appears stock, runs on 92 octain, and will be driven to and from the track 80 miles away.

Its all about timeslips...I don't have my kickdown hooked up,but all I have to do is ratchet down a gear and all heck and even the tires break loose. I think the overcammed,low compression,under geared cars are the slugs,all my cars that have run good at the track have never been slugs on the street. I've never owned a "strip only" car. Gene,hook that thing up and you'll get the timeslip,if'n ya don't break sumpthin :D

if your car can't handle the DP then don't run it. or you might try not full throttling it out of the hole. :rolleyes: but if ET's are what your into then you will ultimately ET quicker with a DP over a VS of the same cfm. and as far as racing, if your car is geared and convertored for it, you will run more consistant with a DP too. that's what i ended up doing to get a little consistancy into my car, toss the VS off and put on the DP. as far as seat of the pants, you can't tell jacksh!t if you're spinning the tires. so if you're hooking it up, and the seat of the pants feels better, then it should be ET-ing better too. at least i've never had one that didn't work like that. now from car to car it's awhole different ballgame. my 93 Z28 feels alot stronger than my 355 powered Chevelle did, but i was wrong. the Chevelle ET'd a half second quicker, just that the car is so much bigger and heavier the engine can't torque it around like that Camaro, plus the Camaro sits lower which gives you a false sense of going faster. another thing is whether your driving or not. driving my car has never felt as fast as riding in someone else's car, even when the other car was almost a second slower than mine. well, maybe that's partly due to my phobia of other people's driving abilities. :D

Nothing compares to driving at the track. When the car hooks, you know it. On the street it's smoking the tires and shifting whenever.
I do notice the difference in the performance level and the crispness of the motor on less humid days when on the street.
I've never been to the track when weather conditions were optimum, looking forward to that.

I'll be able to tell you what happened. I pulled my 750VS off and put a 650DP in it's place and I can't believe the difference in the "seat of the pants"! The track opens this weekend but it'll probably be next weekend before I make it out. I'll post times then. It would be hard for me to believe it's not AT LEAST .2 faster with the DP.....

Originally posted by 70ss496:
</font><blockquote>quote:</font><hr /> quote:
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Originally posted by Georgia69:
In general I favor real ET gains, but there are some things I don't like. Loose torque converters, for example, improve ET but make your car a real slug on the street. If you are cruising along at 20-30mph with a 3000 stall and you nail the gas, all you get initially is mush...poor throttle response. Same with big cams. The only way to get the car to really move is wide open throttle.
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Oh really? That's news to me...mine sure doesn't behave like that. Even with an 8" 5500 flash converter, when I stomp the throttle even at 50 mph, the front end rises up and the car responds right away.

Must be all those rect port head combinations that respond that way .
I tend to agree with Todd. My car's converter flashes to 4000. I don't care what speed it's at it just wants to go hard with no hesitation! Even going down the highway at 55 it's instant tire spin. 1st gear is basically useless on the street even with QTP's. Maybe a mismatched combo would be a dog, but with the right combination on the street I've never driven anything more fun than a car high stall converter. However, if ET reduction didn't feel as fast I'd have to go with ET reduction. Seat of the pants means nothing on the track!

Matt </font>[/QUOTE]My point is, if you're driving along with RPM's below the stall speed, you have to go to wide open throttle to get RPM's up to where the car really goes...just opening the throttle a little doesn't do much with a converter optimized for drag racing. If you've ever compared the throttle response of a stick shift car to that of an automatic, you know what I'm talking about. If you guys can't comprehend that, I can't help you.

Originally posted by Rapid Robert:
Gene,hook that thing up and you'll get the timeslip,if'n ya don't break sumpthin :D Bob, you know it. For sure the way to an 11 sec slip to to try and break sumpthin on this old clutch car. And I can't 'auto' it due to originality and downright fun.

I'll be tryin'! graemlins/beers.gif ( already have some mad money stashed for the clutch/bellhousing redo)

Gene, what was your MPH again? 117?

117.5 on the 2nd run (12.24) 118.75 on the 1st(12.26). Guess I have to test the suspension limits next time. :rolleyes: Got too much $$ in this thing to beat it mercilessly. Gotta stop thinking about money...&gt;AAAAAAAHHHHHHHHH :confused:

seat of my pants, yeah my wife will have them and MORE graemlins/angry.gif after I frag Old Red shooting for the eleven sixties it should run! graemlins/clonk.gif

...and its a real blast to drive graemlins/thumbsup.gif

Thnx Bro. It is a true "seat of the pants" fun ride. Hey any rat-on-a-stick you can turn up to 7G's is!

I'll get my timeslips and Mrs. will have my SEAT in a BIGASS SLING. Bob will be bustin' my chops, wife will be hounding me on breaking a 22K piece of equiptment, etc etc.

, Aw, ain't life GRAND! graemlins/hurray.gif

The true problem here is traction. I like a good tune vac. sec. also because it gives an eng. what it needs vs what the carb wants. Ya get that car to "hook" and the dp should be the man :D

I donnow GM, I think in a case like mr 4 speed, where you're running through mild stall and 2.73s, i.e. a 1st gear ratio of 6.88, most any engine needs a few moments to crank it up, while flipping all 750 cfm at a 454 at once would make the your charge velocity close to zero.

On the total flip side, when I open it up, I show the 440ci rat around 1000 cfm. WAY too much. And my squirters are tuned ( well I am going to try bigger end carb squirters at the track). So you drop the clutch at 3000 and then roll into it, you net out a 2.15 60'. Unacceptable. You bump that to 3500, you need a bit less roll into it and 60' is around 2.05. Next I'll drop the clutch at 4500, and can probably flip all the carbs open immediately, as the motor will be at 6000 in less than a second ( around 6500 actually), and shifting to 2nd in less than 2. Actually the 1/2 shift happens before the 60', we're shooting for a 1.8X 60'( which should take like .5 off the ET.)

IF the tires hold. Big if.

Sorry, I went off on a tangent.....better get back into my "seat" and get to work!

Have'a great weekend y'all! graemlins/waving.gif

Sometimes a good seat of the pants "feeling" doesn't translate into a better ET..thats my point of this post..

Maybe I'm different than everyone else here, but my "seat of the pants" feeling is totally worthless. Last summer, just for fun, I put on a single plane intake and my buddy's 850 Speed Demon. From the "seat of the pants" feel on the street I would have bet my first born son that the car was faster, absolutely no question about it. Guess what? The car went .4 slower at the track! And I had to work hard to do that well. 60's increased from 1.70 to 2.05 (hooked). I also experimented with different carbs. In addition to the 850 DP, I tried a 750 DP, 650 DP, and a 750 VS. The DP's all felt faster on the street but the 750 VS has produced the best ET's with either a single or dual plane intake. This isn't to say that I know how to properly tune a carb. I dunno, maybe if I did the DP's would be faster at the track. I guess my gut feeling is that in a street/strip ride, where the set up isn't optimized for all-out drag racing, a VS carb is the better performance choice.

I hear ya Chris, it seems that "seat of the pants" is usually a top end thing, but we cannot, however, feel the short time differences. you're no different. How it feels, is not a timed event. We can't really tell.

" It pulls harder", usually means up in the higher R's, and Not that you got 4" of air instead of 2". :D

Short times are unmeasurable biomechanically unless you're a really good bracket racer, and maybe not even then. But we can sense if it pulls harder, say at 5000+.

wtf do I know, biophysicist and all, back to my seat again.!

hmm this is very interesting. Maybe I should take off the Holley 750 VS off the chevelle and put it on my Nova (700DP) and see if my et drops.

For example, I suspect, er hypothesize, that in mr 4 speeds ride , the 750 vs might put that ride solidly into the 12's. Might run 13.0 in bad air, for example. As opposed to the 750 DP. HOWEVER, if we bolted in a 650 DP, it might be a different bag-of-tricks.....hmmmmm?

Brad in your case ( NICE DUECE BTW!), the DP is already smaller-sized.

Well I'm not with the crowd here...
I like seat of the pants on the street.
I like being next to some guy at 30 and nailing it and smoking the tires past him or spinning the tires when the trans shifts...
I think that is cool..
Take that with a grain of salt because I dont race at tracks but maybe once a year.

Originally posted by kjett:
</font><blockquote>quote:</font><hr />Originally posted by 10secBu:
Must be all those rect port head combinations that respond that way :rolleyes: :eek: :D tongue.gif . smile.gif </font>[/QUOTE]tongue.gif

Originally posted by mr 4 speed:
Sometimes a good seat of the pants "feeling" doesn't translate into a better ET..thats my point of this post.. i can back up that statement with my 80 z28 i did alot of testing over the last summer with this car and one thing i found out is just because it feels faster doesnt mean it is faster. case in point. i set the carbs vs spring up by feel (nice smooth transition into the secondary's) and went to the track and to my amazement the car picked up 1.3 mph and dropped my e.t. .15 off my time slip with a spring change only (back to back runs) from the stardard spring to the tall yellow..........but out on the street you feel the secondarys kick open and lag just a bit until the engine can use the extra cfm's. but at the track it provides the better e.t. over the seat of the pants feel.

but of course this is from a rolling speed(lighter spring) to where as from a standing start like at the track you dont feel them kick open.

E.T., period!

I've never had my car to the track so et's don't matter. But when the front end comes up, I get planted in the seat and start pulling on the stick I get that big smile on my face and that's what it's about for me. Dave

JMO's here. The vacume secondary carb is a compromize carb period. Any type of a fuel bog multiplies when the vacume drops. Any serious car would be running a double pumper I would think. Years ago street racing with a vacume secondary carb I realized I couldn't reach my full power potential with merely spring changes. The stiffer springs opened late and never fully opened. The medium springs opened better but never fully opened. The lightest spring bogged with a fast opening but did fully open. My lowbuck solution was a screw strategically placed on the linkage located between the primary and secondaries. I see everyone rolling their eyes :rolleyes: This created some drivability problems untill I got used to it. Without a secondary accelerator pump timing the secondary opening was very important, but now the secondaries were opening completely providing for more power. The car went faster. A double pumper is the only way to go--- if it is geared properly so the rpm drop between gears isn't bad. Otherwise you'd just have to learn to feel the pedal. Adjustments to make for long pedal travel makes this easier. If a vacume secondary carb is used to bandaid traction problems then I wouldn't look at the carb as providing a performance increase, fix the traction problems. Any time I feel more power under my seat I know I've made a move in the right direction.

Its been proven at the track that removing the checkball and or the "old screw trick" on vacuum carbs translate into lost ET and MPH..as much as 2 MPH and 1.5 tenths..

E.T. for sure.

As stated above, fix the traction problems rather than detune your car - it will be faster on the track AND on the street.

A few things that I notice when street cars finally make it to the track:
1)A huge number of muscle cars have malfunctioning or worn out differential posi's. In extreme cases their burnouts are mostly one wheel, with the other tire spinning much slower or not at all. When they leave the line one tire spins and the other doesn't. Since this is something the driver cannot "see", they "think" both tires are spinning. Much lost e.t. potential right there - but "seat of the pants" says that spinning squealing tire(s) means that it is "fast".

2) Spinning is not winning; most guys do not modulate or "peddle" their throttle off the line - this is why so many street cars are "faster" at the track with a vacumn secondary carb, it "does" the peddleing for you (not overpowering the tires off the line).

3) In the car under hard acceleration it can "seem" that the front end is rising - when in fact it is the rear of the car "squating" down, usually accompanied by wheel spin. So it "seems" that powerful accleration is happening, meanwhile in reality the differential was unloading and LOSING traction. See above comments about fixing traction problems. Very few street guys seem to understand how important it it to "plant" the rear tires under hard acceleration. Squating = pulling differential up towards frame, Planting = pushing differential down toward the ground. Instead they blame traction problems on street tires - but I can tell you that I have seen lots of properly set up street cars run sub 2 second 60' times ON street tires. For those who have never experienced it, there is nothing like a car setup to "explode" off the line with instant acceleration.

Thomas

Originally posted by Bomber '67:
E.T. for sure.

For those who have never experienced it, there is nothing like a car setup to "explode" off the line with instant acceleration.

Thomas Ha! I experienced it when I lined up alongside mc71454. Instant bumper! AAAAHHHH! graemlins/sad.gif

Well said Thomas

I don't run my or my friends cars hard on the street........if I want to go fast, I take it to the track as that's the safe place to do it. A 10 second or quicker car is a handful on the street and I have too much to loose to end up in some kind of incident. If it's my fault or not, I'm most likely going to get the blame because of the car.

I take the ET slip and that does all the talking. graemlins/thumbsup.gif

I had a friend who's uncle was goofing off in his car and killed his wife and three kids in another car. Now he's on trial and I thank god I never had any issues or have to live with something like that.

No matter what converter, gear or carb you have, a 500+ hp car is gonna jump when you juice it. :D

Just my .02..........

Gene, too funny - too bad it was Tom's rear bumper that was way out in front of your car smile.gif A hard hooking car is a joy at the track, I know of more than a few racers that love the first 60' of the track the most.

Many street guys with 500 hp just sit-n-spin, there are a lot of high hp street cars with NO suspension tuning at all. Too bad really, they have no idea what fun they are missing out on. I do not condone street racing, but if the road is clear I have no problem having a little fun - but the fun ENDS when other cars or pedestrians are present.

Thomas