I've got a 408 that makes 523/487. Rings are gapped for na .020 I believe stock head bolts. Cam is a 251/259 .624.624 114+3. I know I'll need a stand alone fuel system but if say I spray a 200 shot on the stock bolts would it be ok? With a 200 do I need direct port or just a plate? And I have hptuners so tune wise should the only thing I need to do is pull timing in the areas I'm spraying and use the fuel jets that come with the kit as far as fueling? (Still green at hptuners). And what's the rule of thumb for timing to pull with something like a 200. I've got 27 degrees up top in it now. I know I'll need different plugs BR7EF? I've never sprayed anything but I've played with the idea for a long time. Id just hate to pop a new motor. Thanks.

 

If it was a higher compression setup, say 12:1 or higher I would be concerned about lifting the heads. Granted, I would feel alot more comfortable having ARP head studs, but I can tell you of at least 3 different instances where we have sprayed 200+ on an LS based setup with stock head bolts. (Probably wouldn't hurt to upgrade next time you have the heads off.)

You could use a plate or a direct port at 200. If you plan on spraying more than that in the future I would just go ahead and set yourself up with a direct port. If you plan on going no more than 200 then I would just stick with a plate. We have really nice options for both.

We recommend starting with 2* pulled per 50hp from where the motor makes its most power N/A. You want to go 1 step cooler per 100hp on the plug. A BR7EF plug is good for up to 200hp on a fairly normal compression ratio LS motor.

http://www.nitrousexpress.com/20933-...lb-bottle.html

http://www.nitrousexpress.com/20934-...lb-bottle.html

http://www.nitrousexpress.com/90006-...p-jetting.html

Let me know if you have anymore questions or need pricing.

Thanks,
Garrett

 

What type of intake are you running and what's your fuel system components? Also, you should be able to run 200hp worth of nitrous on that with little problem. You are correct in saying that you'd need to pull the timing in the range that your nitrous is spraying, however, if it's a streetcar that occasionally sees the track and won't be on the bottle all of the time I recommend using a LNC2000 to pull the timing. It's just a much more user friendly way of doing it rather than changing between motor and nitrous tunes. The general rule of thumb is to pull 2* for every 50HP, but even at that, you'll still want to get a few sets of plugs and go to the track and make passes. The only real way to tell where your timing is at with nitrous is to read the plugs, and adjust accordingly. For a 150HP shot, the NGK BR7EFs would be a great plug, but if you move up to a 200, you'll want to go with the NGK BB8EFS, and gap them around .028. If you decided to go much more than a 200 though, I'd recommend doing a direct port for the safety and tunability. It may be expensive, but so is a new motor :-/. If it's your first time using nitrous, I'd start small (150hp on a plate system, NGKBR7EFs gapped at .030, and pull 6* of timing) just to get a handle on the tuning aspect, because with nitrous your tune is everything. Let me know if you have any other questions and I'll be glad to help you in any way I can.

 

As stated by both guys, listen to them. One thing I would def do is start small even a 100 to just get a feel for it. 200 is lot to start on for a first time user. Maybe not so much worrying about the hit but how the car is going to react. Big difference in adding 200 on a car from a roll or dig. Standalone was the best thing I did when I did my nitrous. I ran race gas in it just for the nitrous and makes it just a safer tune.

 

I agree with both the nitrous sponsors; listen to them and you'll be fine. I would just stick with a good nitrous plate setup with all the safety goodies. You'll want to make sure you have them so you don't hurt the motor. The most important thing to remember is to tune via reading the plugs and go from there. Your setup is already stout as ****, and a 200 shot will turn it into someone's nightmare.

 

I'm at roughly 11.5 comp and it's a vengeance ported Fast 102 with all 100mm intake tract and speed density. I have hptuners and I keep the laptop in the car so playing with timing back and forth isn't a big deal. Fuel system is just a racetronix pump and Hotwire kit. I planned on going the standalone race fuel route It figured it would be the easiest.

 

Also what kind of trap speed does a 150-200 shot usually pick up. I know it's hard to give exact but I know I'll have to re gear the car. I'm trapping 129 at 3000 feet on motor.

 

At 129 n/a you won't gain as much mph as say someone who traps 109 n/a. With that said you'd probably see around 10-12 mph on a 150 shot...give or take a little

 

200 in the 14-15 range?

 

I'm sure a 200 shot would be in the 14-15 range, but it just depends