If i were trying to sabotage you i would say that turbo. But I don't need to sabotage you to finish higher dynamically. Historically speaking, you're looking at my taillights. 
either get a better sized turbo or use the bottle. Also take into account cost of exhaust headers for the chassis, which you have but were purchased separately versus the included truck manifolds to flip, which you also have. These put the prices much closer for comparison sake. Are you counting the injectors in the turbo pricing? MAF would have to be purchased for N/A. 2-3 bar map would have to be purchaed for turbo.
other things to think about: tuning for the stock engine on bottle is going to be as simple as nothing and it'll run safely. Tuning for the turbo engine is going to require things to be safe. Yes you can download canned tunes from the sloppy site, but you're playing with a grenade with the pin pulled unless you dial it in to the car.
my vote, considering all of the above background information that not everyone was privy to, is K I S S. Nitrous is the easy button.
poopshovel again said:
SVreX said:
Nitrous is LEGAL in the autocross.
Wait. Did I miss something?
Tom brought up in the town hall that he was disappointed in us for not taking advantage of the fact that it isn't a SCCA autocross so nitrous isn't specifically outlawed.
In reply to MrJoshua :
But it was specifically called out as illegal in the rules up to and including the fact that they said no bottles in car during autocross. Which I accidentally violated because we forgot to pull the bottle, but there was no fuse in the system.
when i talked to tom post meeting he said he had to check with insurance stuff before saying yes
How big is that turbo if it's too big for an LS?
One thing to remember is that even a big turbo will make boost right from the start, even if it's not "fully spooled". And that nitrous spools turbos :)
Patrick said:
In reply to MrJoshua :
But it was specifically called out as illegal in the rules up to and including the fact that they said no bottles in car during autocross. Which I accidentally violated because we forgot to pull the bottle, but there was no fuse in the system.
when i talked to tom post meeting he said he had to check with insurance stuff before saying yes
Sounds like more clarification is needed from the big cheese. I'm guessing NHRA probably has rules against using nitrous in the pits as well-but technically the autocross is a race track, not pits........hmmmmmm.
In reply to Keith Tanner :
I have an hx40 and I have this free.
"Hey gearheads, my turbo is too big!" -nobody
Knee jerk reaction says go with the gas, but with an auto and the right tc a turbo may be better in the drags? Better noises surely.
Of course the correct answer is both. Keeping in mind that I've never challenged before so my experience is zilch and my opinion came from the internet.
Stampie said:
In reply to Keith Tanner :
I have an hx40 and I have this free.
Bring them both.
Can we use the hx40 to spool the cat? Twincharged/nitroused/meth injection ls!!!!!
In reply to Dusterbd13-michael :
I suppose if the only thing you're ever going to do is drag race or cone race it makes sense to use nitrous
However some of us racers go race for more than a few seconds . There boost is your friend. I doubt nitrous would last more than a Lap at some of the bigger tracks where real racing goes on.
( isn't time we start some trash talking? )
Stampie said:
If this is Darth Nader the correct size turbo with overkill intercooler and over sized intercooler tubing is a ~$175 budget hit. I have a free over sized turbo but I don't think it's the right choice. I say turbo and nitrous.
Why go to the expense, weight, and complexity of a cooler? Use alcohol and you achieve the same thing. Plus a lot more tolerant mixture
In reply to frenchyd :
Valid point for most types of racing, but he's talking specifically in the context of the GRM challenge, so drag racing and cone racing are the orders of the day.
Okay, that is a big turbo :)
rslifkin said:
In reply to frenchyd :
Valid point for most types of racing, but he's talking specifically in the context of the GRM challenge, so drag racing and cone racing are the orders of the day.
I was trying to provide the requested arguement. I even added some "trash talk" in hopes to stimulate conversation.
PS I should have put a big smiley face because previous attempts at humor tend to really fall flat.
In reply to NOT A TA :
Go big or stay at home. If ya can't run with the big dogs stay off the porch.
Anybody ever play with proportional (PWM?) control over nitrous so you can vary the amount of boost and make the tank last longer in a setting like autocross? Sure for drag racing you just want it all, but if nitrous is autocross legal then part-throttle nitrous would be nice.
dculberson said:
Anybody ever play with proportional (PWM?) control over nitrous so you can vary the amount of boost and make the tank last longer in a setting like autocross? Sure for drag racing you just want it all, but if nitrous is autocross legal then part-throttle nitrous would be nice.
If you really wanted to get fancy and you've got an electronic throttle, you could map it so WOT on the engine is before full pedal travel and the rest of the pedal travel delivers an increasing amount of nitrous (potentially also scaled based on RPM). That way you don't waste nitrous when the engine alone could deliver more power than you're currently asking for and you retain linear power control rather than an on/off snap of nitrous.
For the scenario you presented, nitrous. Less budget. Invest in torque converter, and cam. More well rounded performance. You really don't need nitrous on an autocross, IMO. The hit to concourse might even things out though.
If you want to make more than 600hp, turbo.
It's all about goals...
Keith Tanner said:
Okay, that is a big turbo :)
I once worked on an HX82 applicaiton that had a 2KG impeller wheel.. It was for a tug boat v16 with 8 turbos..
Nitrous.... to spool that huge turbo!
Regarding biggest mess:
Is a Jet Turbine powered supercharger illegal? I forget the name of those, they used to be used drag racing in the 60s...
dculberson said:
Anybody ever play with proportional (PWM?) control over nitrous so you can vary the amount of boost and make the tank last longer in a setting like autocross? Sure for drag racing you just want it all, but if nitrous is autocross legal then part-throttle nitrous would be nice.
It's quite common to use it this way too in drag when you have big shots and limited traction. I have tuned setups with multiple hits all PWM controlled to keep the car hooking.
Hard to find a turbo too big for a LS that doesn't have a T5/6 housing. You have specs on that beast? You can go 8.x easy on an 80mm T6 with a mild LS setup and just an "ok" chassis.
Oh and if I can't vote both I vote nitrous.
Nitrous on the autocross should be encouraged, with the button on a remote given to a random spectator.
If we're going there...
Who's going to be the first person to recreate the Turbonique rear axle for the Challenge?
