I have a great fuel system (1/2 inch fuel line, 140 GPH pump), stock GM powder rods with ARP bolts, 5140 forged crank. I also know I have to run 112 octane. Will hyperutectic pistons survive a dual stage 250 shot???

 

A buddy broke a ring land at 575rwhp, so going dual stage you may or may not be able to get into the 600hp area. It's a gamble I going to be taking to at least 550rwhp and maybe higher.
Robert

 

Yeah...I agree with Robert..if you split up the hit...or only hit it above say...4000 rpm...that will help alot. And it also depends on the mods and power level you currently at. But I personally believe they will handle that if set up right. Id say try to limit TQ to 650 or less and HP to 650 or less as well and you should be ok.

One of the NX/FJO mini controllers would help a bunch as well.

 

only one way to find out. film it please

 

Your on borrowed time with a 250rwhp shot on the stock hypercrap pistons. Its not that an Ls1/6 stock bottom wont handle 600+rwhp, its getting it all via the violence of nitrous. Id do it with a progressive controller to limit the torque spike as suggested.

 

Yes like he said progressive controled wouldnt that be best for that big of a shot? Im going that route and was just curious of how much better it would be to go that way rather than 2 stage with a 200+shot.

 

More fine tuning ability. I like my dual ws and a first gear lock out for second stage. 1st stg on at 3000rpm in first gear, 2nd stg on at 4100rpm in second gear, and a 3rd stage on at 5100rpm in second gear also. I have a vette, so have to watch IRS, shafts, drive shaft, trans case, 3rd member case, along with allowing the bottom end to live. I will probably stay with this set-up cause I know it and how to make it work. you can do the same with a progessive 1 or 2 stage set-up.
Robert

 

Roberts may i ask how your running your 3 stage ? are you running a controler? What do u mean by dual ws?

 

my buddy did it in a bolt on 02 Z, 150 shot off a window switch, 100 shot on a button...put down 566 rwhp at the dyno with the clutch slippin a little...it's not a question of if, it's a question of how long

 

I use a MSD pill type window sw on first stage. A MSD rpm activation sw, pill type, on 2nd stage, tied into 1st stage ws so it shuts off at same rpm, with a wot sw (special 3 terminal) on shifter (pics in my web) to lock out second stg in first gear. Now my third stage is being reconfigure and I may be using a progressive controller and a direct port, but right now it's a dry hit and prob continue with another rpm activated sw. third comes on in second gear also (tied into shifter wot sw) and all stages shut off at 6400rpm and I shift at 6500. It seems complicated but really is all automatic and very tunable. I can run any one stage, or two stages, or all three.
Robert

 

It can handle it but you need to have your tune exactly right, run race gas, progressively controlled would help, and take other safety precautions.

Good luck!

 

Yep, stock clutch won't last long, I upgraded to the aussie clutch. I have about 150 passes this summer from small hits to big hits and broke nothing or ruined any clutches. I sold my stock clutch and it's now in a Camaro and he races. I chose to upgrade early on, cause stocker I could feel it slip on hard runs.
Robert

 

That is alot of stuff. and thanks for the info Roberts

 

I grenaded a piston and 8 rods on a 200 shot. made 623 RWHP and 763 RWTQ though.

 

i don't think the eutectics will last long on a 250 shot,progressive or not.just my $.02

 

You are absolutely right....they wont last long, no question about it.

 

he had a Spec Stage 3

 

if you have a bone stock motor that makes 300 rwhp and you run an actual 250 shot split up into two stages that keeps the TQ down around 525 at each point each stage activates and the total HP is around 550 rwhp that motor will last a LONG time as long as you are using the right octane and tune.

If its a cam only car that makes 380 rwhp and you use the above kit set up in the same way...or better yet progressively to make 630 rwhp...I believe it will still last barring any malfunctions. The key here is to keep the TQ down.

On a motor with a large cam and heads making 450 rwhp + the 250 shot....now you getting up there and anything goes.

But operating under these conditions leaves little room for error with those hyper pistons....or anything in the motor for that matter.

BTW this isnt just theory here We had a heads and cam car that made 680 rwhp...stock bottom end. He made right at 400 rwhp on motor with an NA tune and right around 390 with the good gas and some timing pulled. He was spraying close to a 300 shot. It was raced regularly from 550 to 680 rwhp over a years time in various configurations.
It finallly had a mishap becuase the owner diluted the race gas with 93 octane while driving it around all night looking for races and didnt have enough octane for his next race...which was from 40 to 180+ mph and it melted a valve while spraying DEEP into 5th gear. The pistons where not damaged. He upgraded to a 408 after that. Even making 650-680 rwhp his Tq was generally kept in the 600-650 range if I remember correctly. Tq management in the name of the game and you have to realize the limits and the stresses that happen with big TQ.

For instance...1BADWS6 obviously had catastrphic damge occur. But look at his TQ. Its insane . But the HP was a mild 623. With a properly setup dual stage you can make 623 rwhp without exceeding 575 rwtq. That nearly 200 ft/lbs LESS that a single stage kit coming on at 3000 rpm.

With something like the FJO progressive setup with the rpm based control you can set you goals on paper first to where you want to limit TQ since that is really the deciding factor in piston failure. If we set 575 ft/lbs rwtq as out maximum goal and use the rpm mode on the progressive and spin the motor to a mild 6000 rpm you can achieve 656 rwhp at 6000 rpm. Thats not a whole lot of stress on those components and the motor will live. If you had a 400 rwhp motor previously...then it would still take a 256 shot to achive that HP goal...but its progressive with rpm.


So dont be afraid of big HP #s...but you have to have it setup correctly.

 

On my car stock everything other than exhaust and lid and fuel pump hit 530 RWTQ At 4000 rpm on a 150shot are you saying thats my limit do to tq spike?
but then if i proggressive controle it the TQ spike will be slim to none?

 

Ws6, what he's sying is if you want your lower end to survive limit the torque peak. If you want more, another stage coming in right about your torque peak or right after. So, 530 peak at 4000 then it will start dropping, then add another 75hp shot at 4200rpm, then another 75hp shot at 5100rpm. Now you have a long linear torque curve rather than a monster spike out of the hole that will continue to drop. Spread the torque out and you will in fact win more races. People can mot believe how hard and long my car pulls for a stocker. Hope this helps clarify things. Thanks Al for taking the time to explain so well and in depth.
Robert