Intros and set up..

[Super73]

I figured I'd post my set up and what it has done so far.

Forged LS1 with 4L80E
11.2-1 compression
243/250 @ .050 108/110 cam
Ported stock casting heads
Edelbrock 1 3/4 stepped 1 7/8 98-02 F-body headers
Stock computer / Harness from a 99-02 F-body
3,200 rpm stall
Stock 12 bolt with 3.73's and a posi

Truck made 409 to the wheels in the video but now makes 428 through the mufflers. I started putting the N20 on it last night with a buddy.

Truck weighs 3840 with me in it and has 59% front (2260) / 41% rear (1580) weight bias.

As far as suspension goes, it's got the stock control arms both front and rear. I am running a 350lbs 14.5" spring in the front along with comp engineering 3-way adjustable shocks and 2" drop spindles. Rear has 3-way adjustables as well as classic performance 2" lowering springs.


Video
http://73-ls1.com/63truck/sac_10_27_07_low_res.wmv



Dyno
http://73-ls1.com/63truck/new_tune_11_27.JPG



Shaun

[Yukon Jack]

Truck sounds great, video was fun to watch. What kind of power will the nitrous be adding?

[Ron 586]

Sounds good. What RPM are you crossing the line at. I know you could stand 4:10 gears but it would be baaad with 4:56 gears in there. Of course if it's going to be on the street you are probably about right. Thanks for posting.

[57sailplane]

hey super73,

ron586 brings up a good point. by my calculations you could be runing 12.1 with the right gears. if everything is perfect..
what is your rear tire dim. outside dia is preferable if you dont no how about tire size like (255r15) and what gear are you in when going through finish.

[Super73]

Thanks for the comments..

Agreed there could be some gearing changes. Right now I'm going through the traps at 6k rpm in thrid, but reving the motor to 7,400. Tire is a 26" tall 275. It dead hooks right now at the track with the 3,200 stall. Before I do gears, I have a 4,200 stall coming and switching to 315/60/15 (30" tall tire). I feel upping the verter right now will really help it out of the hole.

I know if it shifts in to thrird like this I'll be even lower. So what I'm going to try is running it out first and second then locking the converter about 6,800. This should put me back down around 5,900-6k and allow me to cross the traps at 7,000ish at 112mph. Basically keeping second in the power band longer and using the lock up as a third gear.

I'm also making new brackets to adjust the height of the front mount on the rear control arm. By my figuring, the truck has about 80% anti-squat. Thats why it's squating in the rear. If I raise the front eye, it will increase the AS and lift the rear frame and pushing the tires in to the ground harder. I also changed some front stuff around to get more travel and store more energy (springs, removed upper bump stop). Sits a little lower than it did before..

From the dyno above, you can see where I added power with a little more tuning and an underdrive pulley.

The next time to the trackwill have the bottle on it. It'll be a 100 shot out of the hole and a 200 will hit once shifted in to second. I will be using my HPtuners cable to basically make a 2 stage. If everything works out ok, I might bring both stages in halfway through second.

I'm hoping with all the changes it goes 11.80-90 on the motor. Shooting for 10.80's on the unit.


Shaun

[57sailplane]

i ran your combo on some calculators and here is what i have come up with just out of curiosity.

with 428 hp and 3840 lbs your fastest calculated time and speed was 12.10ET at 110.70 mph. to get that speed and mph through the traps you would need a 4.59 gears with those 26 inch tires.

now to get an 10.80 et with the 3840 lbs you need 602.49 hp. which gives you a speed of 124.06 through the traps. to get there with the 26 inch tire you need a 4.09 gear. with a 30 inch tire you need a 4.72 gear.

i am no expert just a bench race junky and this is just perfect world calculations and is by no means a solid true statement. just calculated guesstimates but may give you an idea on things.

[Super73]

Yeah, I find the calculators interesting at the least. The one I use http://www.jcalculator.com/?c=1_4_mile_calculator said I'd go best 12.27 @ 111mph based on my 410 rwhp I made previously. I honestly think with a bigger converter (the 4,200 I'm going with) I would have been faster than that calculation.

I wish I could find one that allows you to put in frontal area, weight, power. Just having weight and mph is great, but what about aero...

Keep in mind though, I am going to a 30" tire. So the gearing will be different from your example. On the unit, I should also be making 630ish. I'm hoping to trap closer to the 130mph mark. If I could lock the verter on the unit a 4.88 would be perfect, but I think it will put too much stress on the clutch packs. So assuming 15% loss unlocked a 4.30 geared 30" tire set up would be great on the bottle. But that is going to kill my NA set up..

All these things to look t and figure out

[SCOTI]

7400! Yikes. Is that LS still set-up w/a hyd roller?

About raising the front mounts..... you could remove each mount & flip them side to side. That should raise the C/L & keep bracket orientation correct.

I enjoyed the video. Put that sucker on a diet & you'll be hitting all your goals. Some skinny/lt. weight alum wheels would be a priority purchase for the fronts & knock a good 50# off the nose.

[Super73]

Scoti,

7,400 on a hyd roller and no valve float or lifter issues (stock lifters and stock rockers)..

I thought about flipping them already, but it doesn't give me any adjustability. I already started making the brackets. Radius drilled the 4 holes, so I will not change the wheel base any. As far as keeping them in the right location, I think I have an idea on that as well.. I'll take pics as I do the install..

[SCOTI]

Originally Posted by Super73

7,400 on a hyd roller and no valve float or lifter issues (stock lifters and stock rockers)..

Off the shelf grind or custom?

[Super73]

This cam is an off the shelf that Thunder Racing puts out. It's about as big as you can go on stock heads with out valve reliefs (I have after market haeds and valve reliefs in this motor though). It has been one of the better performing cams for the 346ci class.

It's 243 / 250 @ .050 with .610/.612 lift on a 108/110..

[Custom 68]

Wow Shaun, that is great. I am running a 5.3 in mine and might be interesed in your converter if you are going to sell, but anyway on your suspension setup, what pinion angle are you running? did you change this? When I did m install I lowered my engine as far as I could by making my own mounts so I think I need to change my rear end some to match it seem sto be pointing up too much.
I need to get mine to hook even with less power than you have?
Thanks
Dave

[Super73]

Originally Posted by Custom 68

Wow Shaun, that is great. I am running a 5.3 in mine and might be interesed in your converter if you are going to sell, but anyway on your suspension setup, what pinion angle are you running? did you change this? When I did m install I lowered my engine as far as I could by making my own mounts so I think I need to change my rear end some to match it seem sto be pointing up too much.
I need to get mine to hook even with less power than you have?
Thanks
Dave

Dave,

I'm assuming you went with a 4L60E trans. My 4L80E converter wouldn't work.

What tire do you have on it?

Ohhh, man, he said the P word... You get so many different answers on pinion angle when asked, it's not even funny. Not to say my ideas are spot on, but, this is how I look at it.

From reading different suspension books and things, I'm not sure pinion angle actually has any affect on how the rear tires are shocked. I think by keeping the pinion in phase under acceleration simply allows you to put all your power to the ground and not loose any extra in friction loss through the drive shaft. So by achieving proper phase at launch will net you the best 60' times.

I recently checked pinion angle. Right now it is +2* (pointing up 2* from being phased with the trans out put shaft). When doing the math to radius drill my new LCA brackets, for every 1" of movement up with the front mounting hole, the pinion would change 1.1* This got me thinking, if the pinion is up 2* and the truck is squating 1-2" on launch currently, the pinion is almost in perfect phase right now. When I change the A/S, I will probably have to adjust pinion angle to get it in to phase again.

[Custom 68]

Sorry Shaun, I didnt read all your first post till now. I missed the 80 tranny. I have provisions for the 80 but yes for now I have a 4l60e. It sounds like you have studied this rear suspension stuff quite a bit. I need to try to understand more so I can make some adjustments. I too had read the pinion "the P word" angle does not help with traction or weight transfer but wasnt sure. I need to adjust mine some is there anyway to change it short of cutting the saddle off the axle and rewelding it? I thought about moving my front connection of teh trailing arm but mine would need to move down to get the desired effect on the angles and from yoru post that woulld be going the wrong way to help with with the anti squat.
right now i have 275 60 15 tires and will be changing soon and thought about the same size you mentioned.
sounds like a great setup you have
thanks again
Dave

[SCOTI]

Originally Posted by Custom 68

.... I need to adjust mine some is there anyway to change it short of cutting the saddle off the axle and rewelding it? I thought about moving my front connection of teh trailing arm but mine would need to move down to get the desired effect on the angles and from yoru post that woulld be going the wrong way to help with with the anti squat.

They make pinion shims (wedges) for the trailing arm saddles. Stock car products has them in their product listings.

[Super73]

Dave,

Scoti is correct, They sell wedges that will allow you to adjust pinion angle. But depending on your truck, your center of gravity could be higher or lower than mine. If it is higher than mine, then you will have more A/S then me right off the bat. Check out this link from pro-touring.com Norm and others do a great job explaining it. http://www.pro-touring.com/forum/sho...ight=antisquat

[Custom 68]

I will do some reading on that site thanks for the link. Now I thought the u-bolts wrapped around and went thru the saddle area. I have not looked close for a while but wont they interfere with the u-bolts? I have helped my buddy do his 1st gen camaro and with leaf springs we did just shim them. I will do some more looking and reading before making any changes.
my motor is the iron block but I installed it very low and slid as far back as would fit with custom mounts I have a 2.5 inch drop in front and I believe 4.5 rear. spindles only in front and springs plus .5 inch lowering block (plate) in the rear I bet our AS is close my center of gravity may even be a bit lower than yours but I bet close. I have not even weighed mine since the conversion

[Custom 68]

ok just an update (2 minutes later) I did find the truck arm shims you talked about...That is great.
They were on stockarmproduct.com
I will see if I can find some local or just order them. I am going to work on this some!
This new section is great.

[SCOTI]

Originally Posted by Custom 68

This new section is great.

Agreed! This section is a cool addition.

[CyanJaguar]

this is a free calculator(it can be quite accurate too)

that takes into account gears, windspeed, frontal area, transmission, tires, cg, converter, rpm specific hp/torque .etc

http://www.maxracesoftware.com/etavbwin.htm

to the OP. NICE TRUCK. thats exactly what Im trying to acheive out of my 64. what are your 60 ft times???

say I dont do anything exotic to the suspension but just add some drag radials on a 10 inch rim, something like 315s? how will I hook???

[SCOTI]

Originally Posted by CyanJaguar

this is a free calculator(it can be quite accurate too)

that takes into account gears, windspeed, frontal area, transmission, tires, cg, converter, rpm specific hp/torque .etc

http://www.maxracesoftware.com/etavbwin.htm

to the OP. NICE TRUCK. thats exactly what Im trying to acheive out of my 64. what are your 60 ft times???

say I dont do anything exotic to the suspension but just add some drag radials on a 10 inch rim, something like 315s? how will I hook???

What part of Dallas?

[Super73]

60's are rather weak right now do to the converter being too tight. 1.87 was my best. I'm moving up to a 4,400 from my current 3,200. That should help a bit.

Going to a bigger tire will definately help, but getting the suspension set up right will help that tire even more.

[57sailplane]

thats aw some. thanks cyanjaguar

[CyanJaguar]

Originally Posted by SCOTI

What part of Dallas?

dallas between Addison and Carrolton.

where are you? Im looking for some help with my build.

[CyanJaguar]

Originally Posted by Super73

60's are rather weak right now do to the converter being too tight. 1.87 was my best. I'm moving up to a 4,400 from my current 3,200. That should help a bit.

Going to a bigger tire will definately help, but getting the suspension set up right will help that tire even more.

I see you dont have the tail gate off. Im planning to take off my tailgate, which would make the rear end even lighter, but I'll move the gas tank to the back.

whats the first thing I need to do with the suspension to get the back to hook. remember it will be a street driven truck(weekend bruiser)