Intercooler2

iTrader: (24)

Made/making some big changes trying to hit mid to high 11's just bolt-ons. Last two that I don't have are 1.85 ratio rockers or FAST 92/92. Which one is worth doing? Any kind of gain with the rockers worth mentioning?


Also if I do rockers what other parts are needed for the install? New pushrods, valve cover gaskets, springs, retainers? Any concerns with piston to valve?

What about the FAST? What is required to slap it on?

03Sssnake

iTrader: (20)

Stock Cam there should not be any piston to valve interference with 1.85s. You will want hardened pushrods and some better springs, you may also consider the TI retainers to lower mass in valve train.

Intercooler2

iTrader: (24)

Suggestions on springs?

03Sssnake

iTrader: (20)

On the stock cam, you could use the Z06 yellow striped springs, and or if you want something better look at comp 918s or PAC 1218s. Both of those are good to .600 lift.

david vericker

iTrader: (1)

I have a complete Comp Pro Magnum 1.85 roller rocker kit that is just setting on my parts bench.The rockers have less than 3000 miles on them.My present stroker cam has way to much lift for 1.85 rockers so I went with HS 1.7 roller rockers.If you are interested in the comp 1.85 rockers shot me a PM...I will let the entire kit go for 40% of the original cost.

Intercooler2

iTrader: (24)

PM sent

teke184

iTrader: (5)

should see a solid 10-15hp gain with the rockers, between the increased lift (main contributer) and the small decrease in friction on the valve.

the fast should show some gains, but not sure how much you'd get for the money. might be better off getting the 90mm LS6 upgrade from TPIS.

03Sssnake

iTrader: (20)

Teke is spot on. I would not expect any real gains from the fast on a bolt-on only car. H/C car, different story.. You already have the LS6 intake and ported TB, so I would call it a day.

Intercooler2

iTrader: (24)

What is this:

90mm LS6 upgrade from TPIS.


Well I am doing full bolt-ons only for my car so I thought if putting the FAST 92/92 on would gain me 10 RWHP it might be worth it. No mods left but that one or possibly a 85 MAF and 85 MAF lid. Guess the rockers are the end of the line.

teke184

iTrader: (5)

the jury is still out as to whether there is power to be gained from he FAST on a stock engine....particularly over the ls6 intake.

it's possible to gain a little power, but its possible to lose power in the low end at the same time.

and for the $900 cost (intake/tb...minus $300 from selling your ls6) that's a hard bill to swallow for only 5hp.


but if you have the means....i say DO IT!!! dyno before and after too. you'll make a good amount of friends by providing the information.

i wish i could afford to dyno my car before i put the ported FAST on it. but having to drive 3hrs to get to a tuner, not to mention the cost associated with the dyno...it just isn't possible.

ss.slp.ls1

iTrader: (36)

For the price of a fast 90/90, you could buy a cam kit and yield much better results. The LS6 intake is a nice peace, stick with it until you have a big cam. I suggest that if you don't want a cam now, get the 1.85 rockers, hardened pr's, but get some 918 springs, as suggested earlier.

Intercooler2

iTrader: (24)

My goal was to get there without ever going inside the engine like cam or heads. Gotta find the +1 HP's here and there and maybe lighten later if I don't get there.

ss.slp.ls1

iTrader: (36)

You will find that the more hp you make, the more $$$ it will cost to make additional hp without touching the cam and heads.

david vericker

iTrader: (1)

Reply sent.

Alt

iTrader: (6)

If you pull the trigger on that FAST, let me know what you plan on doing with your ls6 manifold. I can save you shipping and I'll just pick it up since you're not too far away.

Intercooler2

iTrader: (24)

I got the 1.85's off David. Advice I have gotten says keep the LS-6 so that's what I am doing.

Intercooler2

iTrader: (24)

How is everyone doing lash when going 1.85's?

Spizmo

iTrader: (1)

I looked at the 90mm upgrade from TPIS a while ago and all they do is cut off the stock TB mounting flange and glue on their enlarged flange that matches their oval 75x90mm TB. With this setup, and taking the screen out of the MAF, they said it made 18.5 lb-ft and 32.3 hp over the stock LS6 setup. There is an artical about it in the December 2005 issue of Hot Rod mag. if you can find it. The car they tested it on also had a TPIS-ZL15 cam on it. If I remember right, when I called for a price I think is was around $849 for everything.

405HP_Z06

iTrader: (11)

The following instructions were originally developed for Crane roller rockers but works equally well for any adjustable stud mount rocker arm.

http://www.vincihighperformance.com/...TRUCTIONS.HTML

One turn on the rocker nut from zero lash equals .042" lifter preload. If your using stock lifters, I would recommend 2 full turns.

Intercooler2

iTrader: (24)

Seems kind of complicated but sure it works. Hope I can get a socket on the crank bolt to spin it over unless someone has a better way of turning it.