joe flannery

I am working towards running my car at the MusclePalooza event at Englishtown in September. I have yet to take the car to the track. The MusclePalooza event will probably be the first time I drive it on the track.
I have changed the springs in the distributor for a quicker curve. I have a Magna Flow exhaust 2-1/2" stainless steel system. I have a new set of BF Goodrich T/A radials with 255/60-15s . The gears are 4.11 with the close ratio trans. The torque is advertised as 360LB@ 4,000 rpm and the horse is 330@5600. The redline is 6,500 rpm. I see no sense in revving it that high since it peaked about 1,000 rpm earlier. The tach is off by about 150 rpm.
The question is this. What should I shoot for as an optimum shift point ? I figure 5,000 should probably be around the best place to shift. Anyone out there that used to drag their stock LT-1 ? Thanks for your input . Joe

7T1vette

If it is a "stock" built LT1 and it won't rev to at least 6000, there is something else wrong with it. If the valve springs are old/worn out, you will lose the top end. Or, perhaps the secondaries on the carb are not opening completely or linkage is not set properly. If your engine were performing properly, the limiting factor in your car's configuration would be the T/A Radials not being sticky enough to put all that LT1 power to the pavement.

DRIVESHAFT

In general, quickest ETs are typically obtained by shifting slightly above peak hp.
If peak hp is at 5600 you will likely go the fastest by shifting around 6000 rpm assuming your valves dont float.

BKbroiler

You must have meant to type 6,000 when you typed 5,000 as a shift point.

Gordonm

6000 is about the best shift point with iron manifolds and pretty much stock LT1

joe flannery

I'll give the 6,000 RPM shift a try. I thought it was best to shift a little earlier and be between peak horsepower and torque peak in the curve. The engine is in great shape . The car just turned 35,000 miles this weekend. I am sure that I have plenty of tire for a little LT-1 when I see guys running in the 10's on old bias ply poly glass tires with an L-88 under the hood. This is the event that Hemmings Muscle machines sponsors. This is the first time that they will be holding the event in Englishtown . It should be fun.
The car surprised me the first time I really got into it. I was with my son on RT 9w in Alpine. The tach was not working at the time- so I have no idea what I shifted it at. I grabbed second gear and it broke the tires loose so bad it got a little sideways. I really didn't expect more than a good chirp from second. I don't know if it will get loose like that again now that I have new tires on it. The other tires had maybe a 1,000 miles on them. They were from around 1982 . I got rid of them.

morganjd

trust me, those tires do not hook up, the bias ply goodyears are night and day, just run them at 40lbs of air in the rear (yes 40 lbs)You need to walk the car out of the hole, if you spin the tires, you will loose time. A 60 foot of 2.0 will be real good, let us know how it runs

joe flannery

I am a little confused . Which tires are you saying to run 40lbs of pressure in. The factory sticker in the glove box area says 24 lbs. Obviously that is for street driving and the stock type tire. I understand the 40lbs is for less rolling resistance in the front tires. You are also saying 40 in the rear as well , correct ? Should the modern radial be inflated for 40 lbs if it is on the rear of the car or those re pro wide oval bias tires as well ? I would of thought they would be run soft. I only run the stock pressure all the way around . You think it would hook a little better with more than 24 lbs ?
I seem to remember reading some old roadtest in which they added more air in the rear tires and it actually hooked better. I can't remember where I read it -but it is not unheard of .

PRNDL

Never heard of anyone inflating to 40lbs. Typically guys are letting the air out of their tires at the strip, then line up at the airpump to reinflate before heading home.

You probably want to shift at 6k, but as a first timer be careful. Hope you aren't planning to powershift. Especially with a faulty tach. I rely heavily on my "ear" to tell me when to shift, but at the track with a helmet on and possibly a very noisy car next to me I can't hear my own engine. With no rev limiter a missed powershift or even losing traction and not realizing how fast your engine is turning.... can mean a blown engine.










Don't be fooled by that. With modern radials you may still have a real hard time hooking up. I have no idea how those guys launch with repro bias ply tires. I have asked them, and never got a satisfactory answer. I suspect they use some kind of glue.

Solid LT1

Please do all of us Vette owners a favor and hit the Drag Strip before the event to familiarize yourself with Drag Strip proceedure and driving technique. My big pet peeve about Vette owners is that many have no prior expirience before hitting the Strip. Concentration and expirience can subtract a 1/2 second from your ET at the drags, nothing worse than seeing a LT-1 run 15 second 1/4 mile times and being beat by a 289 Mustang.

joe flannery

I agree with everything that you wrote. I have been to the track in other cars. I have had a 68 Charger RT 440 auto 72 Chevelle SS with an LS-5 . The Chevelle was a great car. It ran 13.6 for its best ET. Once I had 108 mph in the Quarter with it . I used to drive those cars to the track and back.
This is just my first time with the Vette. Who knows it may be the Vette's first time at the track too. I want to change the valve stem seals on it before I race. I have heard oil in the cylinders can cause the engine to ping - requiring less ignition timing to stay out of detonation. I also intend to get a real good alignment done just before I go. I want the car to track as straight as possible. I am hoping for say 14.2 at hopefully 100mph flat.
I remember when I ran the Chevelle with the LS-5 , I used to shift it before redline for the best ET. Sometimes you waste timing going all the way to Redlline. That is really the reason I figured I would start this thread. I wanted to know what other guys with the LT-1 have found out. I really would like to try it a couple of times before the Hemmings event.

morganjd

the blue vette was owned by wayne nelson and the silver car is owned by JJ. For the strip only we all run 45lbs in the front and 40lbs in the rear!! With say 32lbs in the rea, what you get is the tire cupping and it burns the outside edges. The way to check correct tire pressure for the repop bias ply goodyears or firestone wide ovals is to do test burnouts aqnd keep adding air untill the burnout marks are even across the tire. Or you can do a burnout and use a heat gun and run it across the tire, the test burnout is easier and more fun!! The 2 vettes above are at the top of pure stock racing, wayne sold the blue one, but JJ still beats on his and just won in june at martin. BTW, the wide ovals are softer than the goodyears, and are said to hook better. On radials, it is a different game, as the sidewalls are stiffer and do not work at high tire pressures, it did not matter when i ran them, they dont hook up. And no they do not add glue or any other traction enhancers, you cant believe how soft the repro bias ply tires are

not a '76

no matter what anyone says, acceleration is a power integral. you want to shift to maximize the area under the power curve. that means going past power peak a bit before shifting...