Roots/Twin Screw G37x
10-23-2015, 08:09 AM
#16
Registered Member
iTrader: (13)
I too wished that vortex made their own kit. Stillen air to water is straight thrash. Boosted performance custom air sc stillen kit still needs work but that's more so for the guys that already have the stillen kit and have a few thousand lying around to play with. Gtm/gamma can't get my money for there's.
In pertaining to this thread, my knowledge base isn't as vast as u or those commented but sub'd for progress. Might learn a thing or two.
In pertaining to this thread, my knowledge base isn't as vast as u or those commented but sub'd for progress. Might learn a thing or two.
10-23-2015, 03:12 PM
#18
10-23-2015, 04:37 PM
#19
Registered Member
iTrader: (13)
Not dismissing their kit at all,. But post something we can actually buy 
. We "all" know how that went here and on the Z forum.
Yes the kit is great but not available unless its used and then GOOD luck if you ever need a part for it :/
. We "all" know how that went here and on the Z forum. Yes the kit is great but not available unless its used and then GOOD luck if you ever need a part for it :/
10-26-2015, 03:04 AM
#22
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Does anyone know offhand what the stroker engines are making while still N/A?
The more I think about this and start building my parts collection I'm left knowing that no matter how much power is made I WILL get bored, and I will end up taking it to the strip.
Therefore building the bottom end should be investigated further and all options.
So, to the title question,
When it comes to the Stroker kits I'd love to know what the gains are before boosting. The torque increase should be significant making the AWD G37 a beast off the line.
As for cost I'm ignoring that for now just to add to discussion and have a bit of, "if I could afford anything, what could I possibly do and what would be the outcome?" As I see it IF you're doing the bottom end (and not having to pay labor) at least try and do some upgrades other than just strengthening (if possible and worthwhile).
Theory and Hypothesis
The vq37vhr makes roughly 94.25chp per liter so using some very fuzzy math, going to 4.5l would net 424chp with no other mods and torque could go up a ridiculous amount. There would be a loss in RPM with could make the automatic trans go nuts.
With the added boost of the supercharger and now a built and larger bottom end let's just say 4.5l for estimate numbers, looking at the 500-600hp range (using a midrange boost pulley ((Lg pulley 7-8psi/M pulley 14-15psi/Sm pulley 28-30psi)) running 14-15psi on a 4.5l shouldn't be an issue to reach the goal.
The estimated numbers aren't including fine tuning and full exhaust upgrades. If we use a rough number of 10chp per PSI gaining 140-150chp isn't crazy especially when you add in the gains that the Water Meth Injection (WMI) will produce sprayed pre compressor. Spraying before the compressor (turbo and SC) increases the efficiency of the compressor substantially. Along with the added efficiency the WMI will raise the octane level from 93oct to 100-110oct making knock an almost non issue and possibly allowing for not having to lower timing at all on low to medium boost levels. The other obvious benefit is the cooling of the intake pre charger air making for a denser and less likely to detonate post charger air. It is also possible to run a leaner AFR, getting as close as possible to 12.5:1 or 13:1 while in boost will make for the best torque numbers.
Using Osiris software will allow for multiple tunes since WMI rely on something that can run out, having a tune with lowered timing and a richer AFR will keep things safe. Other tunes could vary in power greatly depending on if use of the WMI is fully taken advantage of or not.
Basically I'd expect to see (realistically) 500-575chp with 14psi and no other mods other than WMI and OSIRIS for tuning (essentially support) on a 4.5l engine.
Here's where the interesting thing comes in to play, I'd actually expect the 4.0l and 4.2l engines to put down nearly the same amount of CHP as the 4.5l since the RPM on the 4.5l would be drastically lower although the torque would be much higher on the 4.5l. The reason for this is "horsepower" is the amount of work you can do in a certain period of time and amount of work translates to torque. Therefore, Torque in a certain amount of Time = HP. With more RPM and less displacement you can make more HP and with Less RPM but more displacement you make more torque (think Honda VTEC engine vs a Diesel or big c.i. Gas V8).
This is where the use of the car comes into play when deciding which route to take. For a drag car we'd want high revs and with a daily we'd want more low/mid torque for stop and go. Meeting in the middle seems the best choice for a daily driver that will see the occasional pull here and there.
Another positive using a Supercharger over turbo's in the situation is the absence of lag and the linear delivery of power. Really any supercharged stroker setup being set for (higher) Torque or Horsepower will still be good on the street since torque delivery won't have any low spots while waiting for full boost.
**THIS POST IS BASED ON VERY ROUGH ESTIMATED NUMBERS JUST USED TO DEMONSTRATE THE DIFFERENCE IN SETUPS**
***If anyone has any, or can find any PRE-BOOST stroker dyno numbers I'd greatly appreciate it***
**Dyno numbers would also show the loss in RPM for the TQ gain on larger displacement**
*common stroker sizes and estimated peak output 4.2/395chp, 4.0/377chp*
**As I noted these numbers are just estimates based on liters divided by chp of the stock engine, torque numbers I didn't even bother because they will gain much more than hp numbers.
The more I think about this and start building my parts collection I'm left knowing that no matter how much power is made I WILL get bored, and I will end up taking it to the strip.
Therefore building the bottom end should be investigated further and all options.
So, to the title question,
When it comes to the Stroker kits I'd love to know what the gains are before boosting. The torque increase should be significant making the AWD G37 a beast off the line.
As for cost I'm ignoring that for now just to add to discussion and have a bit of, "if I could afford anything, what could I possibly do and what would be the outcome?" As I see it IF you're doing the bottom end (and not having to pay labor) at least try and do some upgrades other than just strengthening (if possible and worthwhile).
Theory and Hypothesis
The vq37vhr makes roughly 94.25chp per liter so using some very fuzzy math, going to 4.5l would net 424chp with no other mods and torque could go up a ridiculous amount. There would be a loss in RPM with could make the automatic trans go nuts.
With the added boost of the supercharger and now a built and larger bottom end let's just say 4.5l for estimate numbers, looking at the 500-600hp range (using a midrange boost pulley ((Lg pulley 7-8psi/M pulley 14-15psi/Sm pulley 28-30psi)) running 14-15psi on a 4.5l shouldn't be an issue to reach the goal.
The estimated numbers aren't including fine tuning and full exhaust upgrades. If we use a rough number of 10chp per PSI gaining 140-150chp isn't crazy especially when you add in the gains that the Water Meth Injection (WMI) will produce sprayed pre compressor. Spraying before the compressor (turbo and SC) increases the efficiency of the compressor substantially. Along with the added efficiency the WMI will raise the octane level from 93oct to 100-110oct making knock an almost non issue and possibly allowing for not having to lower timing at all on low to medium boost levels. The other obvious benefit is the cooling of the intake pre charger air making for a denser and less likely to detonate post charger air. It is also possible to run a leaner AFR, getting as close as possible to 12.5:1 or 13:1 while in boost will make for the best torque numbers.
Using Osiris software will allow for multiple tunes since WMI rely on something that can run out, having a tune with lowered timing and a richer AFR will keep things safe. Other tunes could vary in power greatly depending on if use of the WMI is fully taken advantage of or not.
Basically I'd expect to see (realistically) 500-575chp with 14psi and no other mods other than WMI and OSIRIS for tuning (essentially support) on a 4.5l engine.
Here's where the interesting thing comes in to play, I'd actually expect the 4.0l and 4.2l engines to put down nearly the same amount of CHP as the 4.5l since the RPM on the 4.5l would be drastically lower although the torque would be much higher on the 4.5l. The reason for this is "horsepower" is the amount of work you can do in a certain period of time and amount of work translates to torque. Therefore, Torque in a certain amount of Time = HP. With more RPM and less displacement you can make more HP and with Less RPM but more displacement you make more torque (think Honda VTEC engine vs a Diesel or big c.i. Gas V8).
This is where the use of the car comes into play when deciding which route to take. For a drag car we'd want high revs and with a daily we'd want more low/mid torque for stop and go. Meeting in the middle seems the best choice for a daily driver that will see the occasional pull here and there.
Another positive using a Supercharger over turbo's in the situation is the absence of lag and the linear delivery of power. Really any supercharged stroker setup being set for (higher) Torque or Horsepower will still be good on the street since torque delivery won't have any low spots while waiting for full boost.
**THIS POST IS BASED ON VERY ROUGH ESTIMATED NUMBERS JUST USED TO DEMONSTRATE THE DIFFERENCE IN SETUPS**
***If anyone has any, or can find any PRE-BOOST stroker dyno numbers I'd greatly appreciate it***
**Dyno numbers would also show the loss in RPM for the TQ gain on larger displacement**
*common stroker sizes and estimated peak output 4.2/395chp, 4.0/377chp*
**As I noted these numbers are just estimates based on liters divided by chp of the stock engine, torque numbers I didn't even bother because they will gain much more than hp numbers.
10-26-2015, 09:18 AM
#23
Registered Member
iTrader: (13)
I dont think anyone has done just a NA build, ex: one guy but dont remember his name sorry, again, GTM did a stroker kit FI and made something like 800WHP. But their not a "real" option but at least its a number. NA build will cost you about 10k, I prices one out earlier this your and was getting a stroker(4.2) motor from importpartspro, Kyle s good people too! Vendor here.
10-27-2015, 05:59 PM
#27
Yes he did but he spent a lot more than one would to TT their car. Staying NA is just not a very cost effective option. Especially when you consider that you are going to have to live in the upper RPM ranges to see any of that power so it's not all that useable. Just boost it and be done
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