Bye Bye thirteens

[ed hess]

So last nite I only got one run in.
Seems either a check valve failed or the return valve failed between the cell and the street tank. Havent looked to see which yet. But the cell emptied itself into the tank while waiting in the lanes. Truck died as the lane started to move forward after a long wait. So i ended up missing that run.

Anyway the only changes i made to the truck were all tire pressures at 28 psi like my tuner told me to do. As well he had me do what he calls a dry hop before pulling to the lights. Basically like a small launch, but just spin them enough to get the water off without heating them up, which would make the street tires slippery.

He watched and told me I was still spinning all the way thru the 60ft so suspension mods and drag radials will be next.

Results
Rt .041 <--- using the new nhra light system. But still pretty damn good.
60ft 1.76 best I ever saw on the old motor was 1.8x
1/8th 8.050
1/8th mph 83.01

¼ ET 12.74
MPH 105.79

I told my tuner I would do the the rear suspension mods but im not doing the front end till I get to the point where I can get the left front tire up. Then after I get a photo of it I will. I figure this would be a pretty cool thing to have.

Since the old motor seemed to avg 13.7 I guess you could say im now halfway there!

Ed

 

[ed hess]

forgot to add one thing.

I launched at 14 lbs <---thats not a typo, of boost and ran only 15 lbs base.
No controller yet for higher boost.

Still not sure what controller to get.

also it spins so much i cant figure out where the 1-2 shift is looking at dm

ed

 

[pattyfun]

hhmmmm
I think you should avoid the water box if you're running treaded tires. It will always drip down and/or spin to the surface and cause traction problems. Just a thought.

 

[smeagol]

Have you tried launching with lower boost, just to see what the results were?

My old sy, couldn't launch over 4psi, or I had 1.9x 60' times.

There's lots to tuning 60', not just getting good tires.

As far as tire pressure, Mike Vielhaber did a ton of testing. Not saying your local guy is dead wrong or anything, but Mike had some impressive results with his truck.

Playing with front ride height, via torsion bar adjustment has a big impact.

Personally, I'd run higher tire pressure in front - we have a LOT of weight up there in a Sy. Testing will reveal what's best... I don't think there is a single correct answer as too much comes into play - weight of vehicle, tire model, suspension setup, ride height, and so forth.

I've done 1.68 on a set of Sears radials, set with 30-35psi front, high 20s rear. I've done 1.62 on a set of Nitto drag radials, with pressures in the 20psi range all around. I don't think one time bests are saying too much.

 

[TURBO TY]

greddy makes a sweet boost controller . it is called the PRofec e-01 boost controller. it list for 680.00.
www.greddy.com

 

[Captain Morgan]

Ramchargers has a boost controller thats cheap and works very well from what i hear.

 

[E-Rue]

im gonna have to agree with brian....... in my sy i have to launch with 3 or less psi to get good 60ft times. i ran a 7.5@90 in the 1/8th on low boost. thats with a smaller cam than yours, some L35's and a PT52. even with the 11" ZR1's out back, i still spin badly on anything more than 3psi at the line. im not sure how these other guys are launching with so much boost and not blowing the tires off. doesnt work for me at all.

although your 60ft times really dont seem that bad......

e

 

[sytyguy]

Touching a little more on what BG said about tire pressure.....I read the writeup about Mike V's experiment with tire pressures. Having done a good bit of lightening up on my truck, I decided to do the same tests and see what tire pressures gave me the best results. Here are the results of my test:

The Test

I found 2 mailboxes on a long straight road with no traffic (I live in BFE, so these are EVERYWHERE). These 2 mailboxes don't have to be an exact distance apart, just a good bit (say 1/8 or 1/4 mile apart). I got up to 50mph and at the first mailbox, I let off the gas. I coasted until I reached the 2nd mailbox, at which time I recorded the mph by gauge and DM. I changed tire pressures (more in front than rear) until I reached the highest speed at the 2nd mailbox. I did about 8-9 different pressures/tests.

The Results

On the first test, I was at 28 mph when I passed the 2nd mailbox. This was with 32 psi in all 4. Next, I tried 2 psi more in front & 2 psi less in rear. Speed at 2nd mailbox was 29 mph. This told me that there was indeed less stress on the drivetrain and the truck was coasting easier (but I was skeptical that it could have been driver error - letting off a little late). I kept doing tests and getting a little more speed, until I tried 39 front/28 rear. At this pressure, I passed the 2nd mailbox at 34 mph....a 6 mph difference from test 1. I tried more in the front and less in the rear, but it started slowing back down at one point.

My pressures may not work for other trucks as I have reduced the weight of the front end substanitally, difference in tires, difference in wheels, etc....The trick is finding what works for YOUR truck. I haven't verified any traction testing, but I plan to take these results with me to the track next time and spend a night just trying different tire pressures and observing the 60 ft times and trap speeds. Should be interesting. I will post what I find here.

Michael

 

[hamrhead]

Yup. What Brian said about launching - LESS boost. I tried launching with 13psi once or twice when I was running 12.0's, and the damn thing just spun like nutz into 2nd gear. After that I tried more like 3-5psi and improved my 60's.

With my current motor I launch around 5psi and can haze 3 drag radials, but managed some 1.6x 60's so far (so far = 2 whole runs down the 1/4 :roll: ). I have a 3000 stall and ZR1's w/ BFG Drags- 275/40/17 Front and 315/35/17 rear. No suspension mods right down to the original shocks.

Just got the head gasket fixed and everything seems to be good so far!! Maybe hit Atco soon.

 

[ed hess]

i might be a maniac but:

The way i see it, its easier to launch at full boost like im doing unless i get a boost controller that can limit boost on launch. But being a nut i figure the way i will approach this is fix the traction proplem so i can launch with everything i got. I mean the big shots do it that way, at least i think they do.

Fixing the traction problem from what ive learned is going to consist of drag radials, shocks in the back that limit down travel, rear sway bar, caltracs, and shocks in the front that can limit up travel.

That looks like about something around 1500 give or take. This inlcudes the 500 for the oem wheels i found. Nittos look to be around 139 each. might sound like a lot, but not when i look at how deep im in allready.
Then boost controller is probly gonna be 200-500. egt meter arrived today for tuning. That was 270 or something. no dobut theres gonna be more stuff. Like a tranny unless this holds up but i dont see how it possibly could in the long run.
So any way get past this part and then i can start doing some tuning with higher boost levels. I know that end the end of this eventually there is an 11 sec timeslip!

 

[ed hess]

mike
you postded while i was typing that. Surprised to see you smole the drag radials. So do you have a boost controller so you can launch with lower boost. Otherwise its gotta be a pia trying to watch the gauge and the tree at the same time. I would think thats impossible and still get a good reaction time.

also were you using the drag radials when launching at high boost?

Im not totally sure from what you typed?

There has to be a way to launch at high boost so you can use all the bottom end torq coming out of these builds.

ed

 

[smeagol]

Very few combinations on radials are going to allow for leaving the line with that high of boost Ed. Tony launched with high boost, but he had monster drag radials all around as well, and a suspension that allowed for some weight transfer.

When i had Nittos all around, i once left 3 tire tracks 75 feet long, with a 10-12psi launch. There was * NO * traction available at that point.

How do the big shots do it? Perfect chassis, perfect suspension, monster slicks that are warmed up, perfect weight transfer.

Our trucks have many shortcomings compared to real race cars for full 1/4 mile racing.

 

[ed hess]

brian

So with that i guess the only way to launch while still using as much power as possible would be to get a boost controller that can control separately for launch. Then keep testing various boost levels till you find the best "controlled base boost for launching". not to be confused with base boost as set on a wastegate rod.

Also i would think all these other things would help but also would need to do the above.

ed

 

[Will_in_China]

1.8 60' leaving line at 18lbs and bald all seasons.
Of course this is all useless info because I'm at 5800ft which fucks up all the data and makes it useless.
Gald I could contribute!


-w

 

[smeagol]

Best solution for consistent launch boost & RPM

External gate with low base boost spring (Innovative stuff)
Innovative boost controller, with input from brake switch

MSD 2 step rev limiter


with this setup you can launch with whatever boost you like, as well as whatever RPM you like. it isn't cheap, which is why few people have this setup.

Or you could put an external wastegate on your intercooler plumbing, but that *can* be bad for the turbo.

I hate the watch the boost gauge method of launching, but there aren't many serious racers here if you haven't noticed. By serious i mean competing in points competitions, who have *made* money in organized racing events, and in a consistent fashion.

As far as leaving with full boost - good luck... there is a LOT that comes into play here, and you'll be hard pressed to find someone who will leave at full boost on radials. One key is that you must have a linear progression of power - typically a LARGE turbo, and a motor geared towards higher RPM, so you don't have a BOAT load of torque down low. Also, our gearing isn't the best for a good turbo launch. Buicks have great gearing, hardly any change it. Go compare our 1st gear ratio to a Buick's.... going to a 350 or 400 tranny gets you back to a taller first gear, which is better for our buildups IMO, but you lose the OD.

tuning tuning tuning.. you'll have to find out what works for you. Honestly, if i was you, and serious about best consistency, look into some big drag radials - 275 front, 315 rear, on 17" rims. Doing the external with a good controller will help you fine tune, but you are talking about another $1000. Also, if you are running a 15psi base boost spring, no controller will be able to control it below 15psi. keep that in mind.

 

[hamrhead]

mike
you postded while i was typing that. Surprised to see you smole the drag radials. So do you have a boost controller so you can launch with lower boost. Otherwise its gotta be a pia trying to watch the gauge and the tree at the same time. I would think thats impossible and still get a good reaction time.

also were you using the drag radials when launching at high boost?

Im not totally sure from what you typed?

There has to be a way to launch at high boost so you can use all the bottom end torq coming out of these builds.

ed

No boost controller. I run an external wastegate on my crossover and a bleeder valve to adjust boost. I try to stage before the other car and stall out the converter watching the boost gauge on my pillar. Try to shoot for about 5psi before I let it go, but I'm not bracket racing so R/T is of no real concern to me.

When I tried launching with high boost(like 3 years ago), I was still running the stock wheels and tires, so I'm sure that had alot to do with it. When I say stock , I mean from the factory. So yes, the tires were old and dried out a bit. :roll: Maybe when I go next time I'll try a little higher launch? Shit, I just have to get there...

 

[steve-o]

howdy,

thought i'd throw my .02 in here. compared to many of you, i'm a noob so hopefully you all won't flame me too much. i came up with an idea for a cheap dual stage boost controller. i not sure if it'll work though so let me know what you think. sorry if it sounds confusing.

my concept consists of two regulators plumbed in parallel in a dual port config. i was thinkin that by splicing in a air solenoid(s) that will switch the regulated pressures to the wastegate (the "top" end port). you can switch between the two pretetermined boost settings that the regulators are adjusted to.......have i lost you guys yet? in other words you'd be turning one regulator off and turning the other one on..... by means of a switch in the cab or even wiring it into the brake lights. so do you think that such a gismo could work or do you think i'm smokin crack here? ...just an idea.

was browsin' through mcmaster-carr's online catalog and found that they sell a veriety of air/liquid soleniods. many are two-way and some are three-way, they all have different "flow" ratings, but most all dc versions run off 24v. theres gotta be a way to make them work on 12v......i hope. most are reasonably priced and made from different materials there are sooooo many to choose from and don't know which one(s) would be best suited for this application.

thanks all

 

[smeagol]

kinda like this

http://www.turboxs.com/Dual Stage Boost Controller.htm

 

[SY1373]

Sounds like your truck will be a monster when tuned. I know you are not looking for 1.7X and 8.00 (1/8ths) - I have consistently done this with stock EVERYTHING (7.80's and very low 12's documented on numerous timeslips - with a little help). With my stock setup 8 psi yielded best 60' & et. I have never had the "problem?" of spinning the tires thru second.

Watching the boost gage and tree is not as bad as it first appears. Stage first and when the other lane stages (or prestages), start building boost.

Buck

 

[FLSY2730]

Sounds like your truck will be a monster when tuned. I know you are not looking for 1.7X and 8.00 (1/8ths) - I have consistently done this with stock EVERYTHING (7.80's and very low 12's documented on numerous timeslips - with a little help). With my stock setup 8 psi yielded best 60' & et. I have never had the "problem?" of spinning the tires thru second.

Watching the boost gage and tree is not as bad as it first appears. Stage first and when the other lane stages (or prestages), start building boost.

Buck

You have gone 7.80s on stock everything?
What did you do to it , high boost?, shed some weight?
Just curious.