nitrous use and trans slip?
06-24-16, 10:47 AM
#1
nitrous use and trans slip?
So from my perspective it seems like all the nitrous users put down nice pretty dyno numbers making another 100-200 hp but when they go to the track they barely run quicker than the NA cars.
Im just trying to understand why? Is the trans just not able to use the power well at the track?
Is the nitrous only useful if you are doing a highway pull in a gear or two?
Im just trying to understand why? Is the trans just not able to use the power well at the track?
Is the nitrous only useful if you are doing a highway pull in a gear or two?
06-24-16, 11:12 AM
#3
From my understanding the main issue is putting the power down in the first gears. It seems that most people start spraying late in the 1/4th of miles so you don't see much of the benefit. As far the transmission slipping I heard that is an issue but only with a really big shot of nitrous.
06-24-16, 11:19 AM
#4
https://www.clublexus.com/forums/is-...le-record.html
Check out his thread from the 1/4th mile IS-F record
Check out his thread from the 1/4th mile IS-F record
06-24-16, 11:30 AM
#6
Theres a lot of variables, but usually overall power will show itself in the trap speeds even if the 60 foot and ET is crap. Maybe just something with the tuning and these 150 shot of nitrous not giving a true 150 hp
If a 400~rwhp car is trapping 118-120 in good air you would think some of these 450-550 rwhp nitrous cars would be going towards the 130 mph range.
I believe this car that trapped 133mph was running a 225 shot and making 630 rwhp with ms109 race gas as well
Last edited by sc3dreamin; 06-24-16 at 11:38 AM.
06-24-16, 11:32 AM
#7
https://www.clublexus.com/forums/is-...le-record.html
Check out his thread from the 1/4th mile IS-F record
Check out his thread from the 1/4th mile IS-F record
An RPM switch that sprays from 3k to 6,500 rpm might be a good way to take some pressure off the transmission during the shift maybe
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06-24-16, 01:23 PM
#9
06-24-16, 04:16 PM
#11
Pole Position
Im very familiar with drag racing and what it takes to go faster....just seems like ive seen a lot of guys with nitrous not running any faster than a few of the bolt on NA cars have done in good air 11.9@119-120 mph
Theres a lot of variables, but usually overall power will show itself in the trap speeds even if the 60 foot and ET is crap. Maybe just something with the tuning and these 150 shot of nitrous not giving a true 150 hp
If a 400~rwhp car is trapping 118-120 in good air you would think some of these 450-550 rwhp nitrous cars would be going towards the 130 mph range.
I believe this car that trapped 133mph was running a 225 shot and making 630 rwhp with ms109 race gas as well
Theres a lot of variables, but usually overall power will show itself in the trap speeds even if the 60 foot and ET is crap. Maybe just something with the tuning and these 150 shot of nitrous not giving a true 150 hp
If a 400~rwhp car is trapping 118-120 in good air you would think some of these 450-550 rwhp nitrous cars would be going towards the 130 mph range.
I believe this car that trapped 133mph was running a 225 shot and making 630 rwhp with ms109 race gas as well
I know we're a year removed with different temps but like you said you would think the trap speed would've been closer to 142-43ish...........he couldn't figure it out either
06-24-16, 04:31 PM
#12
I have a 2012 isf and 100 shot, i have a window rpm switch, so the car starts spraying at 3500rpm, I took it to the drag strip, i ran 13.5 without the nitrous, i live in Colorado 6000ft elevation. Then with a 100 shot I ran a 12.5 one second faster, and that's with some wheel spin in first gear, on street tires, my best et was 2.2 because I couldn't get any traction, so if I drop my et I can even run a better quarter mile, I don't ever experience any transmission slip, car runs strong, so for a 100shot to improve 1 second I think is really good. I'm going to buy drag radials and go run again and let you know how it goes
06-26-16, 09:42 PM
#14
Originally Posted by kitabel
As long as your RPM window chip keeps nitrous use away from upshifts you should be safe.
However: if you lift, or short-shift, remember that nitrous doesn't add HP (work over time) but cylinder pressure, and a 100 hit at 3,000 during an upshift is not healthy for friction materials.
There are other ways that IMHO some shops have used (or still researching) to keep nitrous and/or boost continuous through upshifts by reducing power. This should be using the actual shift event (line pressure change, solenoid voltage, shift valve motion, not shift RPM) as the trigger. These include:
1. waste gate release (but lags, spools down turbo)
2. BOV release (better but still lags, drops manifold pressure)
3. spark retard keyed to transmission shift solenoid (best, briefly raises EGT to keep spool up while killing 75% of HP (or more)
However: if you lift, or short-shift, remember that nitrous doesn't add HP (work over time) but cylinder pressure, and a 100 hit at 3,000 during an upshift is not healthy for friction materials.
There are other ways that IMHO some shops have used (or still researching) to keep nitrous and/or boost continuous through upshifts by reducing power. This should be using the actual shift event (line pressure change, solenoid voltage, shift valve motion, not shift RPM) as the trigger. These include:
1. waste gate release (but lags, spools down turbo)
2. BOV release (better but still lags, drops manifold pressure)
3. spark retard keyed to transmission shift solenoid (best, briefly raises EGT to keep spool up while killing 75% of HP (or more)
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