Stepping up to 150 shot

[MattD]

I'm gonna go ahead and step up to a 150 shot. I've got colder plugs on the way and I can turn my timing down with the Diablosport. Anything else that I should be prepared for?

 

[ZmanM3]

More Power!!!!!

 

[2007 GT/CS]

I'm gonna go ahead and step up to a 150 shot. I've got colder plugs on the way and I can turn my timing down with the Diablosport. Anything else that I should be prepared for?

What are you using now?

 

[psfracer]

What are you using for your fuel system? BAP?

Confirm your a/f with either your wideband (if you have one) or the dyno, I ran a fuel jet .003 larger then called for to get 11.5 a/f. On the 150, use the best gas you can get--at least 100 octane--cheap insurance and your plugs will live longer. I stuck with the stock gap with the 125 shot, but when I went with the 150 shot, I gapped them down to .035.

What tires do you have? If you have some good dr's, then great. If you don't, then don't bother, you just going to spin the tire anyway unless this is for 3rd gear and higher.

Lastly, make sure you have a window switch. I made literally 175+ nitrous passes squeezing right out of the hole (auto, aftermarket 3000 converter), so I thought I didn't need one. When I went to the 150 shot, I had probably a good 20 passes or so, maybe more, then this happened:

 

[matt texass]

psf wat exactly happened im just curious

 

[psfracer]

I still don't know exactly was caused the nitrous backfire. The engine still turned over, but alot of stuff above the clyinder heads were destroyed. Hood, windshield, intake manifold, fuel rails, etc. No fire though, so I was lucky. I think something held an intake valve slightly open, and the combustion traveled from inside the cylinder into the intake manifold, then boom!

 

[ZmanM3]

I still don't know exactly was caused the nitrous backfire. The engine still turned over, but alot of stuff above the clyinder heads were destroyed. Hood, windshield, intake manifold, fuel rails, etc. No fire though, so I was lucky. I think something held an intake valve slightly open, and the combustion traveled from inside the cylinder into the intake manifold, then boom!

Man that sucks! I am glad you are ok though. So looking on the bright side, are we going to see a rebuild thread? And a thread about what happened and what you found?? Again the important thing is that your ok and no one got hurt!

 

[don_w]

Man that sucks! I am glad you are ok though. So looking on the bright side, are we going to see a rebuild thread? And a thread about what happened and what you found?? Again the important thing is that your ok and no one got hurt!

I'm pretty sure all that info is about 6 months old now... his rebuild is done and he's running low 7's with the Whipple now.

 

[psfracer]

Man that sucks! I am glad you are ok though. So looking on the bright side, are we going to see a rebuild thread? And a thread about what happened and what you found?? Again the important thing is that your ok and no one got hurt!

Yeah, this happened at the Hangover Nationals at LACR on 12/31/2006. I have since gone with a whipple and the car has been running since late April. I just wanted to make sure if MattD went up to the 150 shot---that he not follow in my footsteps by not having a window switch and squeezing right out of the hole. As far as what I found---as long as you use the best gas you can get---engine wear due to nitrous seems minimal. Here are some of the tear down pics I took in my garage when I pulled the motor. Over 60k miles and the bearings looked pretty good I thought.

MattD--once again just make sure when you run the 150 shot that you use the best gas you can. If you look at the last pic, you can see how thin the piston is from the top to the first ring land. You need to make sure you do not have any detonation so your plugs and pistons will survive.

 

[Yoggie_Bear]

I am moving up from a 75 shot to a 100 shot. Can I use stock pugs with stock gaps, if not what do I need to gap them too. Has anyone done this before?

 

[psfracer]

I personally would use HTO's, stock gap for the 100 shot.

 

[Yoggie_Bear]

yea i think the HTO would be better but, what did you ues?

 

[ulev1st]

So how much power can a stock bottom end take before the rods let go? I have the Whipple but I also have a Zex wet kit that I've never even turned the bottle on yet..I'm afraid the bottom end won't hold it..The car isn't completely tuned yet cause the stock clutch started slipping on the dyno..right now it's at 440 to the wheels with the clutch slipping. I have a new Ram dual disc to install once the ARP flywheel bolts get here and we can finish tuning it..(if the belt stays put). Is it safe to hit the spray on a 75 shot on top of the blower or just hold off until I can afford to build the bottom end first?

 

[psfracer]

Damn! How much boost are you running now? My first thought was, if its not enough, just up the boost and not worry about the nitrous. Detonation is what kills these motors, when in doubt, run the best gas you can (100-104-109) while racing.

I have no experience squeezing with a supercharger. Greg does, maybe he can answer some of your questions.

 

[psfracer]

yea i think the HTO would be better but, what did you ues?

That is exactly what I used, Hto plugs with stock gap for the 100 shot

 

[MattD]

What are you using for your fuel system? BAP?

Confirm your a/f with either your wideband (if you have one) or the dyno, I ran a fuel jet .003 larger then called for to get 11.5 a/f. On the 150, use the best gas you can get--at least 100 octane--cheap insurance and your plugs will live longer. I stuck with the stock gap with the 125 shot, but when I went with the 150 shot, I gapped them down to .035.

What tires do you have? If you have some good dr's, then great. If you don't, then don't bother, you just going to spin the tire anyway unless this is for 3rd gear and higher.

Lastly, make sure you have a window switch. I made literally 175+ nitrous passes squeezing right out of the hole (auto, aftermarket 3000 converter), so I thought I didn't need one. When I went to the 150 shot, I had probably a good 20 passes or so, maybe more, then this happened:

Sorry for the late reply. NOS's kit comes with a window switch so that is covered. I'm spraying between 3200 and 6300 rpm.

The tires I used were M/T's drag radials. They were wore out and I ended up taking too much air out of them. My best 60ft of the night was a craptaculiar 1.79.

I made 9 nitrous passes and my mph was never any lower than 112 and the highest was on my best pass of the night which was a 12.05 @ 113.77. The nitrous was actually cutting off before I crossed the traps so I believe that changing to a 28" tall tire will help me out a lot. I'm ordering a set of M&H's soon.

I'm using the stock fuel system with a little bit richer jetting than what was recommended for a 150 shot from NOS's techs. I pulled 5 degrees of timing out with my Predator and had no pinging issues all night.

Excuse my ignorance, but what is BOP?

 

[MattD]

Oh yeah, sorry about your car.

 

[don_w]

Excuse my ignorance, but what is BOP?

BAP = Boost-a-Pump

http://www.kennebell.net/accessories/boostapump/boostapump.htm

 

[SGT4ME]

What are you using for your fuel system? BAP?

Confirm your a/f with either your wideband (if you have one) or the dyno, I ran a fuel jet .003 larger then called for to get 11.5 a/f. On the 150, use the best gas you can get--at least 100 octane--cheap insurance and your plugs will live longer. I stuck with the stock gap with the 125 shot, but when I went with the 150 shot, I gapped them down to .035.

What tires do you have? If you have some good dr's, then great. If you don't, then don't bother, you just going to spin the tire anyway unless this is for 3rd gear and higher.

Lastly, make sure you have a window switch. I made literally 175+ nitrous passes squeezing right out of the hole (auto, aftermarket 3000 converter), so I thought I didn't need one. When I went to the 150 shot, I had probably a good 20 passes or so, maybe more, then this happened:

Ouch.............

The Boom part is what keeps me from doing the Nos.............

 

[F00Mustang]

I'm having the same problem with running out of gear. I'm not only shutting off the spray before crossing the lights, but I'm tapping the rev limiter too. I'm going to also try to find a 28" tall tire so I can clear the traps at the top of forth.

I'm still using the stock wheels for the track, so I'm trying to find something that will fit them with a tall tire.