7000 rpm pop in high gear

[camaroman9]

i dont have any filters on the car fo nitrous. whatever chunk of crap in the line was, it was cleaned out. then we double checked it last friday before we ran the car too. i need a turbo...

[wikd69]

i dont have any filters on the car fo nitrous. whatever chunk of crap in the line was, it was cleaned out. then we double checked it last friday before we ran the car too. i need a turbo...

go ProCharger

[camaroman9]

im probably just going to sit in a lawn chair, drink a couple cold ones and give er the ol staredown. maybe thatll fix it. lol

[John_Heard]

I don't have any other cheap ideas to try... I'm guessing either valve springs or an ignition issue, both aren't cheap to test. Do you have access to an on head spring tester there? I've got one if you want to borrow it sometime.

[blown451]

I would look closely at the ignition and valve springs
are you getting into the rev limiter?
Is your fuel pressure keeping up in high gear ?....If its not you could have a hobbs switch turning the system off and on

[wikd69]

I would look closely at the ignition and valve springs
are you getting into the rev limiter?
Is your fuel pressure keeping up in high gear ?....If its not you could have a hobbs switch turning the system off and on

Ok, I gotta ask...

Whats a 'hobbs switch' ?

[blown451]

This is a hobbs switch .

http://www.summitracing.com/parts/NOS-15750NOS/

I havent run nitrous in a few years but the last time I did all the local tracks said they were manditory ????

We had an issue on one car that the fuel pressure would drop enough down track to kill the switch, then when the system deactivated the fuel pressure would jump enough to turn the system back on ......and so on- and so on- and so on

[supernova]

I wouldn't run a pressure switch on the nitrous system. No control of it, it does what it wants to.
I know it's a safty switch but it can also create lots of other problems. I don't want my nitrous system going off and on at will. I don't think thats a good thing to let happen.

My question is why is the fuel dropping off enough to trigger the switch? Is the fuel system not adequate for your application?

And yes the fuel pressure switch could cause it to pop if it's going off and on down track.

[camaroman9]

Oddly enough, i totally forgot about this thread. Lol. We started all over on our tuneup. By the end, we actually ended up with 26 degrees of timing and 6.5 psi on the nitrous regulator. We went 9.82@127 on one pass before we got it figured out. When we got it figured out, we went 9.83@137 with 14% slippage in the converter.

[bert]

So what was figured out ? I had a sim. issue and found out it was the highside rev limiter in my MSD 7al3 box. Mine would pop at about 7k in high gear but not at the 1st to 2nd shift at 7100. I pulled out the high side chip and no more pop. I needed to go across the stripe at 7500 so I had to up the high rev chip to 8200 from 7600 to keep the pop gone. It was like it would just start to get into the rev limiter early, like not fully in it though.

[camaroman9]

Hell if I know. With the ignition bs we have been dealing with on this other motor, I'm not real sure of what the hell the deal was now. The ignition is retarding 6 degrees at 5k rpm, so who knows. I may have just got lucky on that one pass. In the last week, I have changed distributors, distributor gears, check thrust in the camshaft, made sure the outer ring of the balancer wasn't spinning, checked voltage, timing chain is good bc the timing is stable when the motor isn't under load. I'm just not too sure of a lot of things right now. I have called msd twice. They basically said that it won't go away unless I buy a digital box, starter saver, or crank trigger. I'm thinking I just need to upgrade the box and coil.