hey gang,
randy had to take another guy home and then do school work so i offered to post this up for him.
went to atco tonight to run in a class with a buddy of his from hs. it was an ok night, temps in the low to mid 80's.
he got in a bunch of runs, i'll just post the two best. when you look at these remeber, he was no where near his best mph(91mph) and this is with a stock cam, stock heads, stock chip, adn stock torque converter.

60' 2.072 2.034
330' 6.121 6.126
1/8 9.543 9.539
1/8mph 70.74 71.90
990' 12.396 12.403
1/4 14.952 14.998
1/4mph 89.54 87.82

on the 14.95 he let the car shift itself and the 14.99 he was shifting but messed up and pulled 2nd way too early. you can see how much less mph he ran and still had a similar et. unfortunately the track was closing so there wasn't enough tiem for him to try again and see what woudl happen if he got that shift right. i think he would have been able to knock at least a full tenth off, if not more.
hopefully we will finally get aroudn to throwing the good torque converter in his car soon. now that he has the cat eliminator pipe on there you can really hear the car fight the stock converter off the line. i expect to see at least a tenth off of his 60ft times with teh new converter and soem more suspension work.

later
tim

 

What are the mods he has done???

 

ok im awake now so heres the mods....

hedman headers 1 5/8" primaries
heman 2.5" y pipe
cat delete pipe
dynomax bullet muffler
edlebrock performer intake
Ultimate TBI mods w/ AFPR
3.73's w/a Torsen posi
boxed LCA's
open element
smog pump delete
TC lock-up swtich
BFG drag radials 235's
TCI line lock

there it is gang...keep in mind im still running a stock chip and my mph was way off last night so it really needs more tunning...love to talk more but the teachers comming my way

 

Congratulations!


The more and more I read about it, the more I'm convinced the exhaust is about the next biggest thing after the cam in terms of limitations... freeflow really helps our engines... about the only thing I can figure backpressure is good for is o2 sensor readings and emissions...

 

ya keep going liek that randy and tim then ya spray er down with a 125 shot of NOS youd be a def low 13 maybe a high 12 if ya could hit it right!!!!!!!!!!!!!!!


Joe

 

well joe, the next two things that will change in that car are the chip and the torque converter. when you are at teh track you can hear the engine note go flat for a second when it fights the stock converter. there is a 2600-2800 stall sitting, just waiting for the time to put it in.
the chipo will depend on if jp has time before he goes back to school. as you can see the mph fell off a lot as the night went on, even though the air got better.

later
tim

 

Those are good times for his mods. He doesnt even have 3'' exhaust. How much time do you think a lt1 cam would knock off that? Im hoping to see 14 with a lt1 cam and 3.42 posi. we will just have to see...first i have to get the stuff then actually drive 3 hours to a track

 

with the converter, cam, and custom chip i think 13's will happen. teh car already shows it has enough mph to run well into the 14's, just a matter of getting the hook and the mph on the same page adn the car should see a high 14.6 or low 14.7. then he is only a bit of power away from the 13's.
he made those passes with 27psi in the drag radials too, bfg says they can go down to 16psi. so he has a lot left there to work with. along with soem V6 springs in front he shoudl be able to hook the power very well and get the through the stock heads.

later
tim

 

wow congrats on the times. i have pretty much the same setup, cept for the lca's (which will be done soon), the 3.73s & posi, and the tires. but i also got the whole 400 thing goin for me . i was plannin a set of 3.73s, but with the th350 now, i dont think that is gonna be a good idea. nice to see another tbi in the sub-15s category, group seems to be growing all the time. oh, and count me in soon enough too......

 

I need to start working on traction and suspension. I bet I could hit 14s or come very close with some gears, posi, and traction. My mods are basically the same as blackbirds. Actually I may run a tad faster than him since exhaust isnt quiet as good as what I will have soon. Im hoping the new valve springs I just installed will help my top end alittle. I need to start looking for a 4th gen 3.42 rearend. I thought 3.73 was overkill on a lo3. Could blackbird maybe be running alittle faster with alittle less gear?

 

Hey I was down there last night also in a messed up looking 69 Camaro running 12's. You guys should of stoped by and said hi so I could show ya a real engine



Kat

 

kat, if you are gonna be back down there in like 2 weeks let us know. when the converter goes in randy wants to get to the track asap.

later
tim

 

the more and more i read your reply, the more i am convinced you don't know enough about exhaust back pressure.

1 5/8" is perfect, unless you want to see your low end torque disappear. that would translate into a slower e.t., because you wouldn't have the same power getting you off the line.

it's not all about the horsepower rating. i'd rather give up a little hp to maintain or gain torque.

 

well, yes and no. 1 5/8 primaries make it easier to maintain a good power badn if the rest f the system is not well matched to the motor. our cars produce enough exhaust gas to create plenty of back pressure. particularly when you take into accoiunt that most of the guys here run shorty style headers, not full length. teh sooner the exhaust gasses are combined into a single tube the less the primary size is important. with 3inch collectors used by most of the systems that back pressure is easily maintained even after the removal of othe rrestrictions like the cat and shortening the length of the system.

later

 

i would think the opposite to be true. the sooner the gases are combined (as with shorty headers) the more important the length of the primaries is. 'course, i could be wrong. anytime i have seen a setup in a thirdgen, going even to 1 3/4" tubes causes a drop in low end torque. yes, you get a better hp rating (read: increase), but at the sake of the low end torque. hp, in my mind, is top speed, not cranking the wheels around.

 

Well I ran with a cutout today, no headers installed... didn't improve my 60 ft at all.. but my final et was proof of the cat's restriction, I instantly pulled 15.7 and continued with 15.7's all day despite crappy 2.3-2.4 60 ft times...

When they fixed up the traction (sprayed some tracbite on a run of mine) I got a 2.24 60 ft and broke into 15.6...

Here's the best run from today,

humidity at around 60%, temps in the 80's

RT .556
60 ft 2.253
1/4 ET 15.679
1/4 MPH 90.81

I did 2 runs with cutout closed and got 16 flat and 15.9 times... traction wasn't there today though, rained really hard night before.

 

i think we have people looking at two different theories of torque application. yes, larger primary tubes will reduce your peak torque numbers. what will increase from a little bigger tube of the same length is the average torque. it is the difference between completely ripping it right off the line and having torque start falling off quickly and not hittin gthe launch as hard but having it pull harder a bit further.
i like long flat torque tables. it makes for more uniform acceleration through first gear which makes the chassis waaayyyy easier to sort out. if a car hits super hard off the line and then falls off you have to play more games to get it to leave the same way consistanly.
either way you are looking to increase the total area under the curve.

later
tim