Lil Blacky’s official TVS build thread(long post)
#151
Senior Member
Thread Starter
That’s what I said. It will hold at 3k while the gas is all the way to the floor. At the staging lane with the line lock all I have to do it floor the car and the rpms will hold as high as they will fo(around 3k) then let off the button to disengage the line lock. I didnt say I would go past 3k.
#157
Senior Member
iTrader: (1)
I'm not trying to be a douche here, honestly just trying to understand this. I thought 2-step limits rpms by drastically retarding ignition timing/reducing torque and I also thought the primary purpose was to get as much exhaust gases flowing as possible to spool up a Turbo. So in the application of drag racing without a turbo is the 2-step primary function to limit the torque or amount of pre-load on the trans? Say in this case if you didn't have the 2-step what would happen? Would the rpms actually go over 3k and overload the line lock or engine? Or would it hit an equilibrium point close to 3K with maximum pre-load?
#158
There are several types of Rev limiters today. A standard rev limiter limits max RPM by either cutting out fuel, spark or both. Also used by manufacturers since the very early 90's to avoid over-rev in neutral or park only
A two step as in its name has 2 adjustable RPM limits. One for launching and a higher one for shifting to avoid over rev. Again this can be achieved by cutting out spark or fuel.
For anything but a turbocharged engine it is preferred to cut out fuel to avoid backfires and the rinsing down of cylinder walls.
For turbo applications, the first stage of a two step or better known now as an anti-lag system shuts down the ignition only at a slower rate than a rev limiter or by retarding the ignition timing. The preferred method today for turbocharged engines is to retard the timing so much that little power is made but the burning process continues even as the exhaust valve is opening, aiding in turbo spooling. Rather than a cyclic pop or miss you get a random pop or explosion.
If your NA or supercharged, I wouldn't recommend an anti-lag system to avoid unnecessary exhaust system strain.
A two step as in its name has 2 adjustable RPM limits. One for launching and a higher one for shifting to avoid over rev. Again this can be achieved by cutting out spark or fuel.
For anything but a turbocharged engine it is preferred to cut out fuel to avoid backfires and the rinsing down of cylinder walls.
For turbo applications, the first stage of a two step or better known now as an anti-lag system shuts down the ignition only at a slower rate than a rev limiter or by retarding the ignition timing. The preferred method today for turbocharged engines is to retard the timing so much that little power is made but the burning process continues even as the exhaust valve is opening, aiding in turbo spooling. Rather than a cyclic pop or miss you get a random pop or explosion.
If your NA or supercharged, I wouldn't recommend an anti-lag system to avoid unnecessary exhaust system strain.
Last edited by Henry3959; 01-03-2018 at 10:10 AM.
#159
Senior Member
iTrader: (3)
Originally Posted by jdbaugh1
I'm not trying to be a douche here, honestly just trying to understand this. I thought 2-step limits rpms by drastically retarding ignition timing/reducing torque and I also thought the primary purpose was to get as much exhaust gases flowing as possible to spool up a Turbo. So in the application of drag racing without a turbo is the 2-step primary function to limit the torque or amount of pre-load on the trans? Say in this case if you didn't have the 2-step what would happen? Would the rpms actually go over 3k and overload the line lock or engine? Or would it hit an equilibrium point close to 3K with maximum pre-load?
#160
Senior Member
iTrader: (1)
What HGT said. In my Nova it would allow me to hold the rpms just under what the converter would launch at, and then allow me to have a top end rev limit to keep from overrevving. In the newer cars you can set the rev limiter in the computer so it's not as big of a deal.
#162
Senior Member
iTrader: (3)
Originally Posted by chevygirl2006
What nova said and ya mine is going to be on the same button. And there’s a kill switch to turn it off and on when you want to use it.
The Cobalt I just hold the ebrake and let the computer do the high limit and wot box do the starting line stuff.
#163
Senior Member
Thread Starter
Motor is ready to go in. We are just waiting on the transmission to get here from Ohio. It’s in a car we bought. The shipping company was supposed to pick it up dec 26 and 2 times after that and they keep giving us the run around. They canceled the pick up and now we are looking for a new driver. So motor going in is being delayed because we don’t have the trans. We are putting both in at the same time to make things easier.
#164
Senior Member
iTrader: (3)
Originally Posted by chevygirl2006
Motor is ready to go in. We are just waiting on the transmission to get here from Ohio. It’s in a car we bought. The shipping company was supposed to pick it up dec 26 and 2 times after that and they keep giving us the run around. They canceled the pick up and now we are looking for a new driver. So motor going in is being delayed because we don’t have the trans. We are putting both in at the same time to make things easier.
#170
Senior Member
iTrader: (1)
3k stall isnt real high for a 4 cylinder. gm actually had a converter for the old 3 speed th125 that stalled at 3000 for a weak 4 cylinder, i think it was a 2.0l ohv from the 80s. that converter can be put into a 4t45e as a budget high stall as long as you change the lockup strategy from pwm to on/off. 4200rpm would be good for the track, but a pain for street driving.