Introduction/ Turbo GM Truck Project

[gearmesh, inc.]

If you ever get to having to do something with those valve springs, check into a camshaft company called Cam Motion @ http://www.cammotion.com/.

These guys make turbo specific cams and matching springs to go with them. I have seen a few turbo cars that have switched to their cams from the typical off the shelf N/A grinds and picked up significant power increases. The specs for their turbo cams look weird as compared to N/A cams. Intake durations are longer than the exhaust durations. Exhaust valve opening is delayed some so that on the exhaust stroke the piston actually starts heading up some before the exhaust valve opens. This gives more of a "kick" pulse to spool the turbo up quicker and harder. Lobe separation angles are even wider in order to eliminate overlap. Overlap with a turbo setup will result in reversion and dilution of your intake charge. Think of overlap with a turbo as EGR on steroids since the exhaust is pressurized up to the turbo.

[Magoo]

Originally Posted by Foose04

Hows the stang running Magoo?

Sorry just saw this man, the stang has been "under construction" for the last two years essentially. It's out of fuel and I haven't taken the time to upgrade the fuel system. I'm going to convert to E85, just need the bigger injectors and pumps. Haven't really driven it much in the last two years, maybe 1000 miles total. Shouldn't be much longer though hopefully before it's back out breakin hearts

Originally Posted by Carlrx7

ive always 'heard' rumors about, beware the 10 second talon, nice to see it does exist.

It is just that, a rumor.

Originally Posted by Silver-Dollar

How do you like these? Have any problems wth balancing? Looking at picking up a set from tire kingdom.

They are garbage, they're a cheap ass tire for a reason. No traction and they burn up pretty quickly.

[Silver-Dollar]

Glad I didnt spring for them yet.

[Foose04]

Update: True-Trac is in and I love it. It's nice knowing the rear is actually trying to move the truck foward.

Also, even though i'm 600+ miles away from home this week, my friends talked me into dyno'in the heavy chevy. Made three pulls.

Couple issues kept me from better numbers. These include a maxed wastegate spring at 10psi on the dyno. Not sure why, but I can get 11-12 on the streets, but only 10psi on rollers. Also had some HPtuners problems. Truck was shutting down at 130MPH (5700rpms) not sure why since my fuel cut is set at 6300. The throttle % just closes up though, so I have to figure that out.

First pull was in third gear to see how it looked.
Netted: 490HP/469TQ

Then 4th Gear:
Second pull: 506/525TQ
Third: 528/528

Over all, very happy with the truck at this boost level. I would have been more then happy though to take it to 15psi area if the wastegate would have played along. Maybe next time

Slapped little video together: http://www.youtube.com/watch?v=MeZFdAHAaHY

[jmd]

nice.

[toslow]

Congrads bro. Not sure if you tried to text me but my phone is down.

[Silver-Dollar]

Maybe the load difference from street and dyno causing the difference in psi. Got to factor in pushing 4300lbs through the air @ 100+ mph.

[Foose04]

Originally Posted by Silver-Dollar

Maybe the load difference from street and dyno causing the difference in psi. Got to factor in pushing 4300lbs through the air @ 100+ mph.

Thanks guys, and thats a good point silver. I know the truck makes more power on the street as well. I was only using 81% injector on the 528/528 runs. I'm around 98-100% on the streets with the extra 1-2psi boost pressure.

Ow well, its worthless if you cant put it down right? I'm really limited with 20's, but with my brakes I can't go smaller. Plus this is my DD, it has to stop somewhere. So the 275's are getting swapped to 305' nitto 555r's. Maybe it will hook in second at the track??

[minytrker]

Nice numbers. Thats pretty common to see 1-2psi less on the dyno unless you its load bearing. Sometimes you can cheat and strap the vehicle down really tight and get them to make the correct boost.

[bambooi]

Nice numbers!

[gearmesh, inc.]

Nice numbers out of just a little ole 4.8 liter mill. Since your truck is a limited edition of sorts, I was expecting to at least see a factory limited slip unit when I took the cover off......NOT! Just a plain open carrier! WTF?

Good to hear you can get some power to the ground now. Keep us posted.

[Foose04]

I been giving this some thought, looking for opinions. Can the old little 4.8 handle a few pulls to clinch the 600HP mark for nothing more then shits and giggles & maybe a few track runs later on.

Current setup made: 528Hp/528Tq

600hp Plan: remove the Kenny bell boost a pump, install another walbro 255, install stronger wastegate spring, turn timing down to around 15, and turn boost up till 600hp is reached.

Thoughts and or opinions?

Some guys pointed out the ls6 valve springs being weak. How can I tell on the dyno when there not staying shut? Also, still have stock head studs, gaskets, and rod bolts. Any one push these to failure, assuming tune was correct?

Other fun stuff, the true-track and 305 DR's hook awesome, even first gear. However, truck isn't track capable AT ALL with this 5speed nv3500. It refuses to shift into 3rd after a hard 2nd gear pull. This trans only has 25k miles on it, running GM fluids. After the HP is made, some kind of transmission swap will be done, either stick or auto.

[gearmesh, inc.]

Sounds like time to go auto! The dyno may show a little less horsepower with one, but you will be faster.

You can build up boost against the converter before you launch. Then you can see if those new drag radials can really hold!

[bwelch]

you should call out one of these lightnings in the skreet from a roll

[AverageJoe]

Why wasn't this done at Showzone where you got your baseline numbers?

[Foose04]

I sent you a PM Gerald.

As for the dyno, I was at home on leave (ohio) when a few high school buds talked me into dyno'ing. Plus when people ask how much HP the truck makes, it's hard to say around 500HP without having a dyno sheet to back it up. The truck will see Showzones dyno before to long, but will be up a few PSI from the dynojet pulls.

As for running some fords from a roll, I don't mind. I hear most are 10 second rides around here, so they prolly don't want to beat up on my little chevy aways.