Couple Runs, NPB at 11.2

[98Camarod]

Originally Posted by minytrker

Thats my bet also. The springs have lasted way longer than I would have guessed, but you know I was against them from the start.

x2

I've got my old motor that has a comp 230/230 cam, prc duals, cloyes hex-a-just timing chain, melling oil pump, comp lifters for sale if you want that

[OUTLAW]

Originally Posted by Foose04

First want to thank Darryl and Zach for taping a couple runs. I enjoy looking over the video's just as much as I do racing, so thanks again.

Made a new best, that said I've hit a wall and the trucks making the same power even as boost rises. Pretty much at the same power it did with the old 70mm turbo, even at the same boost now 76GTS.

First off I've found couple problems. If you notice in the video's, the truck is pretty damn quiet on the back half and second run. Well my first Jegs brand cutout stopped working and now this one is closing during my runs. It's nearly shut after a pass. My after cutout exhaust is less then impressive press-bent 2.5inch piping and another muffler.

Other then exhaust I think the LS6 valve springs may be opening up when boost is at or around 14-15psi, so there is no gains above that? Thoughts?

Here's the runs : http://youtu.be/aSKJSHVN-rw?hd=1

hey seen you at the track that is 1 fast truck

[Foose04]

Thank you sir, she don't run bad for a heavy weight.

What car you run Outlaw, I wanted to say I met you at some point.

[Foose04]

Well I spoke with the guys over at PAC yesterday, they said their 1518's would handle my application just fine. I decided on those because I really don't feel I need something as aggressive as the duals for a .550 lift cam and stock timing chain. I just need some seat pressure to provide some valve control for another 3-4psi. After that, this setup (short block) is to a point i'd rather not push further.

If I build something down the road and want more seat pressure I have the option to shimming them as most FI cam's still don't have monster lift.

[Audie1]

A lot of good advice given here from some very knowledgeable folks. As a turbo guy I know a thing or two about turbo setups and their problems. Some simple things to check that rob power are vacuum lines. Make sure that they are not cracked or even old. I change mine out every year. Some will seem like they are fine, but when they get hot they can balloon up and you wind up loosing pressure. I use small zip ties and put them on both ends of the lines and make sure they are tight. If your are not making anymore power with the bigger turbo then I would agree with your earlier stated suspicions about there being a bottleneck somewhere. I've never seen your engine setup so I can only throw out some suggestions. Does your intercooler have adaquite sized inlet and outlet ports, is the intercooler large enough to support your engines power level? Is all your piping going to and from your intercooler large enough so that they are not creating a bottleneck? Do you have an EGR Valve, if so is it working and clean (they get gunked up sometimes and can hang open)? Exhaust leaks anywhere between the headers to the down pipe are big power robbers and can drasticially slow down your spool up times. Are your headgaskets good and torqued down correctly? Do you have an automatic trans, and if so could it be slipping? Please don't take any offense if some of these questions might seem rather obvious and simple, as I'm just writing any possibilities down here that I can think up.......Are all your hose clamps good and tight? What type of Boost Controler are you using? Are you getting any boost creep or is your boost steady? If it's creeping then you may need to increase the size of your wastegate puck hole. Do you have a big enough wastegate and is it in good shape and not sticking? If it is not big enough then there is another possible a bottleneck. I would check out some of the simpler things before changing out your valve springs. But stiffer springs and a better cam will not hurt either (as some of the guys already stated). What is your static compression ratio? You said that you are running 20# of boost? What are you gapping your plugs to? I'm running 25+ # of boost and higher boost levels usually require a tighter gap, as was mentioned in an earlier post. On my Buick I run a gap of .032 instead of .035 to prevent the spark from getting blown out. What type of gauges etc are you using to monitor your air/fuel/timing etc? Just asked to make sure you are not getting any knock that would retard your timing. Do you have a knock gauge or audible alarm to sense knock? I'm sure your on top of those things or you would not be running as fast as you are. Just a few suggestions here, you've probably already checked these things, but I'm just trying to pitch in my two cents worth.....Hope you get it figured out though....

[Foose04]

Damn Audie, you pretty much covered all the bases. This should be a pre-flight checklist every time I head to the track.

I'll check and double check a few things and update the forum once I make some progress.

Thanks again for the tips.

[Derek]

Originally Posted by ElecTech

Not really. Their flow numbers are weak on the GM side too. Most buy them because they are cheap and most don't know any better.

[98nbmz]

http://www.ls1tech.com/forums/parts-...l-springs.html

[Foose04]

Well I got the PAC 1518's in from texas speed but haven't installed them... work has been kicking my ass so I took the easy route and finished up the bottle setup so I can use it at the track.

Installed the purge and bottle heater on a switch. Just running a 50 shot, but hope to have enough to trim that .2 off and breaks 10s. I don't know, this fatty truck eats HP...

GoPro Hero is pretty sweet for daytime shots, but pretty rough at night. Over all very happy with hardware it comes with and setup. I'll have that little bad boy with me tomorrow.

God speed to the GM.


http://www.youtube.com/watch?v=gy3CPk15hgk&hd=1

[PapaBear]

Where is this road?

[Matts94Z28]

Next to lincolnville road.

[bambooi]

I installed pac1518s from texas speed too when I had my vette. I removed the ls6 springs asap because of the horror stories...

[Carlrx7]

Originally Posted by Matts94Z28

Next to lincolnville road.

SHHHH, if i hear you, u owe me 5 bucks! just follow the road and drop the money in the 5th mailbox on the left

[chrisheltra]

I bet your chevy forum buddies think your crazy for running a turbo and nitrous on a stock block.

[Matts94Z28]

Originally Posted by Carlrx7

SHHHH, if i hear you, u owe me 5 bucks! just follow the road and drop the money in the 5th mailbox on the left

Pffttt. I used to race on that road back in 03! Some guy who had a blue 350z used to come check it out back then.

[Foose04]

Yeah it's on Carls drag and tune road. I've made about 5-6 runs now, feeling good about the tune.

Chris most the GM forum guys thought my truck would let go 15k miles ago and around 10psi. I didn't know much about the engine and it's limit's, but i'm willing to push the bar for sure. I consider myself ok behind the laptop with tuning, most people told me I'd never keep a 110MPH 1/8 mile talon together for 4 year and 90k miles on a built block I bought used, but I did.

Well see, i'm having fun with it right now and I think thats all that matters.

[Chillerman]

All I know is that truck haul's the groceries pretty darn quick. I hope you get your issues worked out and break into the 10s.

[chrisheltra]

Originally Posted by Chillerman

All I know is that truck haul's the groceries pretty darn quick. I hope you get your issues worked out and break into the 10s.

+1

But I hope I get a 10 first.