gator's 99TA

iTrader: (2)

just like the title reads, at what point are custom nitrous pistons with a thicker crown and relocated ring lands required? it seems many many folks run off the shelf diamond or wiesco pistons in their nitrous motors and running up to 300 shots. these custom diamonds are over 900 dollars. when is it required? thanks in advance.

formulajunky

I am interested in this as well as I was planning a shoot up near 300.

Beaflag VonRathburg

iTrader: (176)

I think the key is compression, cam and how much nitrous. Most of the people on here that run large shots are under 11.5-12:1 with larger cams that tend to bleed off DCR. Once you really start getting up there in cylinder pressure I think that's the time to switch. I don't know at what point, but that's my hypothesis as to the reasoning.

krazy4

iTrader: (5)

The main thing with nitrous pistons is where the rings are located.

Speed Density

iTrader: (38)

How so?

krazy4

iTrader: (5)

I remember reading that at a certain point the rings need to be positioned lower, because of greater cylinder pressure.


Don't quote me, I have never sprayed a 300 shot, just saying what I have read.

WHITE DEVIL

iTrader: (1)

the deeper ringland you have, the less likely you are to lift the ringland. meaning that being on the richer side of things it will puddle and start to pull the ring through the piston to the top, detonation from being to lean will also cause this.

Beaflag VonRathburg

iTrader: (176)

It also has to do with thermal expansion. Having the rings higher up submits them to higher stress. Large shots of nitrous create a lot of heat in the cylinders. With a normal ring package this can cause ring butting which leads to ring failure. Certain things like pistons taper, ring package, and skirt design are very important in designing pistons. I had a conversation with Erik Koenig about this. Here's a thread I created that goes through what goes into designing a set of pistons:
http://lsxextreme.com/showthread.php?p=1731#post1731

krazy4

iTrader: (5)

Better answer than mine lol

gator's 99TA

iTrader: (2)

i know what nitrous pistons are, i wanted to know if anyone believed at what point the custom nitrous pistons are needed. thank you guys

next

iTrader: (9)

My opinion is that at 300 and up you should be on a nitrous specific piston.

krazy4

iTrader: (5)

Around 300 and up.

formulajunky

Thats what I've always thought, My buddy is running 225 shoot and was talking about going to a 300 but wanted to change pistions first, "355" Lt1.

next

iTrader: (9)

Wow, great idea.

fstphx

iTrader: (5)

So full forged (stock block) blue print, balanced, N2O pistons, Hellfire rings, arp studs... How high do you dare go?

Beaflag VonRathburg

iTrader: (176)

300-350. The old white Outlaw car went mid 9s with a 347 using stock rods and off the shelf pistons. Eventually the stock rods distorted and they went to a set of Eagle rods. A lot of people over build their cars.

SLowETz

iTrader: (12)

I'd imagine it's all in the tune(to a certain point), but agree that 300 is getting close to Armageddon on a stock block/4 bolt head.

Never pushed the limits, so dunno "when" is enough to go specific, but we'll be hitting these w/2 or 3 kits(600 total)in an LSx iron block w/6 bolt TFS 235's on top.

JE, custom/one off(13*)N2o pistons...... 12.2:1 dome'd.

Not cheap but neither is peace of mind

Almost a shame to hide these in the motor

next

iTrader: (9)

A lot of people over build their cars???? You really don't know what you are talking about.

Mid 9s on 300 is slow. Hell, I went mid 9s on a stock bottom end 346 with only a 175 hit of gas.

fstphx

iTrader: (5)

I think you and I need to sit down and talk

krazy4

iTrader: (5)

Just agreeing with you.