408 with 12:3 compression i have a stand alone that will be filled with 116 octane but i can get 100 local and i will be running cats . and 100 is the highest i can get unleaded .. correct ? so will i be fine with the 100 unleaded in the tank

 

have you thought about slowly creeping up on the setup?

 

you can get 109 unleaded from vp..

 

well i was going to get it dyno tuned and wanted to do a 150 shot tune and a 300 shot tune . and i wanted to use gas that i could readily get so i wanted to tune it with the 300 and the 100 octane and the 116 in the stand alone

 

The leaded gas is going to damage your o2's and your cats.You have a direct port i assume?Like gator said make a test run with the 150 pull plug and see what it looks like.

 

I would slowly creep up on it man. I run 110 in my fuel tank and 110 in the dedicated cats are turned off. I would do a 200 shot set your timming @15 degrees to be safe get the right plugs in there. then work your way up to the 250 then the 300.

There have been to many guys on here that jump from a 150 to a 300 and something goes wrong and boom. If you have something wrong with the wiring or a bad relay or the tune is off you have a better chance of detecting it when its on a smaller shot. Then fix the problem. BETTER SAFE THEN SORRY. If you have any questions just yell.

 

sounds good guys but it will only be sprayed on the dyno i wont be street tuning,RPM will be doing my nitrous tune

 

Not a good decision. There's a hell of a big difference in the load on a motor during a dyno pull and during a 1/4 mile pull. If you set everything up to where it looks perfect on the dyno, that tune up WILL burn it up when you run it in the 1/4. Especially with the 300

You need to tune the car on the jug under realistic conditions. On the street, at the track, etc!

 

dyno tuning a nitrious car is a big no no,They can set yor timing and everything else,but like said before you need to run it pull plugs check what they look like and go from there.300 is alot if your off your going to hurt ****.

 

Agree with all above - dyno tuning a nitrous car (with much of a shot) is a bad idea... All nitrous tuning should be done on a track (or equivalent)...

 

Okay guys thanks im new to the big shot. I will talk to my tuner and. Try to come up with a game plan

 

Agreed,

This is what spraying a car on a dyno and then hitting the same shot at the track.
Detonation ruined the bearings and crank.

 

Im just curious as to what the big difference is. Will a 200 be okay for the dyno

 

It's still not going to be "right" when you go to spray it at the track. You NEED to make real world pulls with the car at the track to dial the car in. Tuning a nitrous car on a dyno for anything other than a dyno queen is pointless and dangerous, especially on larger shots.

 

The dyno loads differently compared when the car is going down the track. You have more load when you are at the track with the weight of the car pushing against the drivetrain. The dyno has less load which will most likely allow you to run a little less timing. If you end up tuning it that way then run it at the track like that, then it will go BOOM.

You can hit it on the dyno to see what power is made but if it were me I would be hitting it with a small shot like a 100 or 150.

 

Really good advice here^

Remember your tuning margin diminishes as the shot increase. If you want, tune it for the 150's on the dyno, and then take it to the track and see what the plug looks like. Then you can see what kinda timing, jet spread, and fuel pressure your tuneup is liking, then proceed to up your jet sizes with decreased timing.

 

I just wanted to add one clarifying note. Its not that you cannot spray on the dyno, you just cannot use it as a tuning tool. So If you want your "number" thats fine you just need to get the tune dialed in at the track as said above. Then go get your number if you want it.

I would definitely get with your tuner and see what he wants as well. I think keeping the tuner in the loop is a big part of hitting the goals of a project.

I think the average user would be amazed at the difference's between even a 1/8th mile and 1/4 mile tuneup on a car spraying a large shot. ATVracer is a good example as he and shiz take their time and document very well the adjustments they make as the progress in getting a tune-up correct. Ask them if they would even consider making a full 1/4 mile pass with the tuneup they use for 1/8th mile that they usually run.

 

Or 661ft for that matter...

 

Going 1/4 mile racing this weekend !!

We will pull 2* and make a 1000' hit, check plugs and go from there.

Should go in the 7's if we can keep her together.

 

I'll be spectating.... You and your cohort will be banned if I am not impressed

JK guys! Good luck and I hope to see some good times out of that thing!