It was a cool, dark night in Columbia and the dyno operator was late. Dan and I sat in the car at Carolina Chassis Dyno waiting with mild to no anticipation. I talked about the cars on the property.
"Those slicks don't look nearly as wide as the tires on your S13." I said pointing to a red Mustang 5.0 that probably ran 8's or less. "I guess I know where to find 5.0 parts for my Cobra build."
Travis finally arrived and the fun could start. Like most people, Dan and I like to guess how much power we're going to make with cars we bring in. Travis has heard it all before. He regularly sends kids home crying, upset with their output. He says he prefers it that way. He's had enough domestic and imports coming through from small fish claiming x number of power that he knows what to expect. The last time I brought my car Dan and I predicted 125-130 WHP and we were being optimistic. Travis predicted I'd be the lowest powered car the dyno had ever seen. The previous record was held by a 1980's V8 Camero making 148 WHP or so I recall him saying. That day, as we all know, I laid down 150 WHP after some tuning to everyone's surprise. I just barely avoided the shame of being at the bottom of the list.
After bringing in odd-ball cars that make way more power than predicted Travis seems to enjoy our visits now. He knows we're not likely to undershoot our goals as so many others off the street. In fact, just a week or two after I left the dyno the first time, a turbo Civic came in running respectable boost and snatched the lowest output number for himself at 146 WHP. He was none too happy when Dan told him just a couple days back a stock N/A Sentra made more power than him.
Our guess? I'd settled on 240 WHP as the goal. If I made that, anything above it would be gravy. Dan just went along with it. "Hey Travis, we're thinking 240 WHP at 11 psi, what do you think?" Travis leaves that one alone. He wants to see less and I can tell. I really didn't know what I should make. I figured stock GTi-R's make maybe 225 HP and a lot less to the wheels at 8 psi. Put the same turbo stuff on a higher compression engine, run a little more boost and tune it properly and 240 horsepower to the wheels ought to be no problem, maybe a little more. I didn't want to get too excited and look like an idiot if I made less, so 240 WHP was the prediction we laid out to Travis.
I'm glad to know now I was a bit off in my estimation. From the looks of it I was low-balling my guess pretty well. The average people on this forum expected me to make was about 267 WHP.
After shooting the shіt for a bit we strapped the car down and made our first pull. The fuel looked dead on all night (at 12.0:1) but the car was blowing spark and knocking pretty badly. It never does it on the street, but when you load up 4th gear on an eddy current dyno you'll see all sort of knock you never saw before. The run was halted around 4,000 rpm and the rollers whined down.
241 WHP and some torque at 4,000 rpm with spark blowout and detonation.
Great. I'll take it. Time to head home.
But we didn't head home. We took out maybe 6 degrees of timing before torque peak and 5 at torque peak to redline. This is on top of retarding the timing some earlier in the weak because of some detonation. I thought I'd started with a safe timing map, but apparently not. I'll explain more about that later.
Second pull goes much better without any detonation. The spark is still blowing out during torque peak and Travis lets off around 6,500 rpm.
297 WHP and some torque at 6,500 rpm with spark blowout.
I contemplate raising the dwell time on the ignition coils while Travis asks Dan what the spark plugs are gapped to. "0.028 inches" Dan says.
I raise the coil dwell time from 2ms to 2.5ms and advance timing a degree around torque peak. We were worried maybe we retarded too much and were blowing combustion out of the exhaust.
Third pull shows no change in the situation. Travis says to double check the spark plug gap so I take a break while Dan does the dirty work. I have to say Dan gapped the plugs to begin with, so this isn't my fault. Sorry Dan, but they were gapped to a mix of 0.32" to 0.35". Dan fixed the plug gap and we turned the camera on for the 4th run.
I know it's hard to read but it says 321.1 uncorrected WHP and underneath that it shows 303.1 WHP with the weather correction applied.
And the image everyone's been waiting for.
The lower HP and TQ curve is my old N/A curve for comparison.
We messed around with timing, tried to get rid of the odd dips and peaks, and did a few more runs and actually made more power sometimes but I settled on this tune in the end as safe and respectable. Nothing could be done about the dips and peaks.
There are nit-picky things to cover before I let you go. Travis is not used to turbos making any boost early on so some of the runs showed a lot more power earlier on than this one. Travis started at 2,500 rpm sometimes and then as early as 2,000 rpm. Some runs had 8 psi by 2,500 rpm and others had 0 psi at that rpm because he'd not started earlier. The sheet posted does not reflect the power I get early on if I allow the turbo some time to spool early.
The peak torque output is not high. It's actually very low compared to everyone else I've seen. This tends to be the story with our tunes. I haven't figured it out yet, but I'm very happy with it. It means hopefully I won't be breaking transmissions and I can be confident in the weaker clutch I ended up with. The other story with our tunes is that we seem to be able to hold that torque output to much higher rpm than anyone with stock cams. This is where we make our power if you take a look at the sheet.
In conclusion:
303 WHP, 237 WTQ.
Power peak is at about 6,800 rpm. Torque peaks at about 6,100 and 6,800 rpm.
Vadim held the lead in the contest for most of it. No one was even close until he busted out with a serious game changer. I asked Vadim in PMs why he thought I'd make so much power. Here's how it went.
Then coach came out of nowhere at the end of the game with a perfect guess. I had to see what he was thinking so I PMed him to ease my worries that he'd been told how much I made, and see why he thought I'd make so much power. Here's how that went.
So neither of the people who were closest really knew what was going on. I can only assume the other people who guessed 300+ WHP were either confused or at best, wildly optimistic. The average guess during most of the competition hovered around 267 WHP. I'm making a solid 36 WHP above that, and I'm making a bit more than most everyone would have dreamed of.
I'd like to make a shout-out to my man ashtonsser who made me laugh with his comments about those guessing high numbers. There's no way I'd make as much power as that. Good stuff!
I appreciate everyone who participated. I'm real glad I was able to get the data I did and I'm happy to pay coach his winnings. Congratulations coach! Send me a PM with your paypal address and I'll set you up.
I'd like to thank some people specifically and make a few comments on some guesses.
Thanks to Robchaos (235 WHP) for letting me know I wasn't too insane with my 240 WHP prediction.
jpsr20det (236 WHP), it seems you're not the only one who can make power around here. 236 aye? Pfft. =]
Coheed (237 WHP), you seem to have forgotten that you can make power without a VE head. =]
Keo (271 WHP), thanks for the turbo parts! Couldn't have done it without you. Maybe I can make less power somehow to make you happy. =]
snickers (274 WHP), I appreciate you putting a lot of thought into your guess. It means a lot coming from you. Another game changer aye?
MR-4Door-SR20DE (307 WHP), Sorry I couldn't live up to your high standards. Maybe next time. (307 WHP holy madness!).
Vadim (305 WHP), when I saw your guess it was a rare moment. I knew I was going to have to give out the full $50 at that point (I really didn't think anyone would get even close) and that was a sad moment from my wallet.
I can't think of someone else I'd rather have given the money to, so that made it better. =]
coach (303 WHP), the man who understands what stand-alone brings to the table. How does it feel to win now, even though you maybe would have guessed differently if you'd read the description better?
I sort of didn't want to mention this at the end because I don't want to start another dyno chart war but I'll say it anyway. I'm confident in the output I'm making. I have since tested the car against known (stock) quantities and it has performed as one would expect from the dyno graph. Also, the data logs show intake temps really climbing towards redline as the turbo struggles near the end of it's efficiency. There's not much left to make from this T28. In addition to that, I started with a known safe ignition map (based off Enthalpy's standard issue, safe, timing map that he uses to start tuning with) and was knocking. I had to retard timing anywhere from 5-8 degrees in the map to avoid detonation. For those of you who know tuning, this needs no explanation, but for those of you know don't I'll explain. A mixture with more air and fuel will burn faster than one with less. If you have to retard timing, it's because the flame front is reaching the piston top too fast usually due to a quick burn. I was burning so fast, where usually you advance timing from a safe base tune, I had to retard timing. A lot. (I'll post my timing map up later.) This makes me confident I'm making more power with a T28/stock cams/11 psi than possibly anyone else has even thought of. I'm trying to be humble here, but I'm pretty happy with the way things turned out.
How about you?
"Those slicks don't look nearly as wide as the tires on your S13." I said pointing to a red Mustang 5.0 that probably ran 8's or less. "I guess I know where to find 5.0 parts for my Cobra build."
Travis finally arrived and the fun could start. Like most people, Dan and I like to guess how much power we're going to make with cars we bring in. Travis has heard it all before. He regularly sends kids home crying, upset with their output. He says he prefers it that way. He's had enough domestic and imports coming through from small fish claiming x number of power that he knows what to expect. The last time I brought my car Dan and I predicted 125-130 WHP and we were being optimistic. Travis predicted I'd be the lowest powered car the dyno had ever seen. The previous record was held by a 1980's V8 Camero making 148 WHP or so I recall him saying. That day, as we all know, I laid down 150 WHP after some tuning to everyone's surprise. I just barely avoided the shame of being at the bottom of the list.
After bringing in odd-ball cars that make way more power than predicted Travis seems to enjoy our visits now. He knows we're not likely to undershoot our goals as so many others off the street. In fact, just a week or two after I left the dyno the first time, a turbo Civic came in running respectable boost and snatched the lowest output number for himself at 146 WHP. He was none too happy when Dan told him just a couple days back a stock N/A Sentra made more power than him.
Our guess? I'd settled on 240 WHP as the goal. If I made that, anything above it would be gravy. Dan just went along with it. "Hey Travis, we're thinking 240 WHP at 11 psi, what do you think?" Travis leaves that one alone. He wants to see less and I can tell. I really didn't know what I should make. I figured stock GTi-R's make maybe 225 HP and a lot less to the wheels at 8 psi. Put the same turbo stuff on a higher compression engine, run a little more boost and tune it properly and 240 horsepower to the wheels ought to be no problem, maybe a little more. I didn't want to get too excited and look like an idiot if I made less, so 240 WHP was the prediction we laid out to Travis.
I'm glad to know now I was a bit off in my estimation. From the looks of it I was low-balling my guess pretty well. The average people on this forum expected me to make was about 267 WHP.
After shooting the shіt for a bit we strapped the car down and made our first pull. The fuel looked dead on all night (at 12.0:1) but the car was blowing spark and knocking pretty badly. It never does it on the street, but when you load up 4th gear on an eddy current dyno you'll see all sort of knock you never saw before. The run was halted around 4,000 rpm and the rollers whined down.
241 WHP and some torque at 4,000 rpm with spark blowout and detonation.
Great. I'll take it. Time to head home.
But we didn't head home. We took out maybe 6 degrees of timing before torque peak and 5 at torque peak to redline. This is on top of retarding the timing some earlier in the weak because of some detonation. I thought I'd started with a safe timing map, but apparently not. I'll explain more about that later.
Second pull goes much better without any detonation. The spark is still blowing out during torque peak and Travis lets off around 6,500 rpm.
297 WHP and some torque at 6,500 rpm with spark blowout.
I contemplate raising the dwell time on the ignition coils while Travis asks Dan what the spark plugs are gapped to. "0.028 inches" Dan says.
I raise the coil dwell time from 2ms to 2.5ms and advance timing a degree around torque peak. We were worried maybe we retarded too much and were blowing combustion out of the exhaust.
Third pull shows no change in the situation. Travis says to double check the spark plug gap so I take a break while Dan does the dirty work. I have to say Dan gapped the plugs to begin with, so this isn't my fault. Sorry Dan, but they were gapped to a mix of 0.32" to 0.35". Dan fixed the plug gap and we turned the camera on for the 4th run.
I know it's hard to read but it says 321.1 uncorrected WHP and underneath that it shows 303.1 WHP with the weather correction applied.
And the image everyone's been waiting for.
The lower HP and TQ curve is my old N/A curve for comparison.
We messed around with timing, tried to get rid of the odd dips and peaks, and did a few more runs and actually made more power sometimes but I settled on this tune in the end as safe and respectable. Nothing could be done about the dips and peaks.
There are nit-picky things to cover before I let you go. Travis is not used to turbos making any boost early on so some of the runs showed a lot more power earlier on than this one. Travis started at 2,500 rpm sometimes and then as early as 2,000 rpm. Some runs had 8 psi by 2,500 rpm and others had 0 psi at that rpm because he'd not started earlier. The sheet posted does not reflect the power I get early on if I allow the turbo some time to spool early.
The peak torque output is not high. It's actually very low compared to everyone else I've seen. This tends to be the story with our tunes. I haven't figured it out yet, but I'm very happy with it. It means hopefully I won't be breaking transmissions and I can be confident in the weaker clutch I ended up with. The other story with our tunes is that we seem to be able to hold that torque output to much higher rpm than anyone with stock cams. This is where we make our power if you take a look at the sheet.
In conclusion:
303 WHP, 237 WTQ.
Power peak is at about 6,800 rpm. Torque peaks at about 6,100 and 6,800 rpm.
Vadim held the lead in the contest for most of it. No one was even close until he busted out with a serious game changer. I asked Vadim in PMs why he thought I'd make so much power. Here's how it went.
Originally Posted by Vadim
I guess my guess is too high then haha. But just to make it good I'll leave it at 305
Originally Posted by BenFenner
Yah, but that was eventually, with progressive boost. I figured it would take me 18 psi to get there. Maybe 15 if I was real good with my build/tune.
Regardless, we'll see what happens soon enough! =D
Originally Posted by Vadim
Techincally at 14.5 psi, if we take 8whp per psi, then you would be at 266. Now since you seem to be very impressed yourself, and the fact that you squeezed out 150whp out of an NA engine just with ECU mods, I think you are very close to 300.
Plus from our talks before you have mentioned that you were afraid of making too much power and that your goal was 280+ish
Originally Posted by BenFenner
You realize that I made 150 WHP at 14.5 psi (absolute) and it usually takes roughly another 14.5 psi (usually much more) to double power?
Just letting you know how crazy it would be if I made over 300 WHP...
Originally Posted by Vadim
Haha sweet! Submitted my guess
Originally Posted by BenFenner
http://www.sr20-forum.com/turbo/16351-guess-my-output-win-50-a.html
http://www.sr20-forum.com/turbo/16351-guess-my-output-win-50-a.html
Haha sweet! Submitted my guess
You realize that I made 150 WHP at 14.5 psi (absolute) and it usually takes roughly another 14.5 psi (usually much more) to double power?
Just letting you know how crazy it would be if I made over 300 WHP...
Techincally at 14.5 psi, if we take 8whp per psi, then you would be at 266. Now since you seem to be very impressed yourself, and the fact that you squeezed out 150whp out of an NA engine just with ECU mods, I think you are very close to 300.
Plus from our talks before you have mentioned that you were afraid of making too much power and that your goal was 280+ish
Yah, but that was eventually, with progressive boost. I figured it would take me 18 psi to get there. Maybe 15 if I was real good with my build/tune.
Regardless, we'll see what happens soon enough! =D
I guess my guess is too high then haha. But just to make it good I'll leave it at 305
Then coach came out of nowhere at the end of the game with a perfect guess. I had to see what he was thinking so I PMed him to ease my worries that he'd been told how much I made, and see why he thought I'd make so much power. Here's how that went.
Originally Posted by coach
Oh, i thought you were going to be upping the boost, didn't know you limited the boost. at 11psi I bet you are around the 265whp mark, add cams and you are around the 285-290whp mark with the VEMS.
Originally Posted by BenFenner
But I'm on stock cams, and 11 psi...
You think I could make 300+ WHP?
Originally Posted by coach
My buddy with a T28/cams/3" on stock manifolds and standalone put down 268whp at 12psi, went up to 18psi and he cleared 300whp. I think you can get that to.
Brent
Originally Posted by BenFenner
Do you mind explaining your high estimate?
Do you mind explaining your high estimate?
My buddy with a T28/cams/3" on stock manifolds and standalone put down 268whp at 12psi, went up to 18psi and he cleared 300whp. I think you can get that to.
Brent
But I'm on stock cams, and 11 psi...
You think I could make 300+ WHP?
Oh, i thought you were going to be upping the boost, didn't know you limited the boost. at 11psi I bet you are around the 265whp mark, add cams and you are around the 285-290whp mark with the VEMS.
So neither of the people who were closest really knew what was going on. I can only assume the other people who guessed 300+ WHP were either confused or at best, wildly optimistic. The average guess during most of the competition hovered around 267 WHP. I'm making a solid 36 WHP above that, and I'm making a bit more than most everyone would have dreamed of.
I'd like to make a shout-out to my man ashtonsser who made me laugh with his comments about those guessing high numbers. There's no way I'd make as much power as that. Good stuff!
I appreciate everyone who participated. I'm real glad I was able to get the data I did and I'm happy to pay coach his winnings. Congratulations coach! Send me a PM with your paypal address and I'll set you up.
I'd like to thank some people specifically and make a few comments on some guesses.
Thanks to Robchaos (235 WHP) for letting me know I wasn't too insane with my 240 WHP prediction.
jpsr20det (236 WHP), it seems you're not the only one who can make power around here. 236 aye? Pfft. =]
Coheed (237 WHP), you seem to have forgotten that you can make power without a VE head. =]
Keo (271 WHP), thanks for the turbo parts! Couldn't have done it without you. Maybe I can make less power somehow to make you happy. =]
snickers (274 WHP), I appreciate you putting a lot of thought into your guess. It means a lot coming from you. Another game changer aye?
MR-4Door-SR20DE (307 WHP), Sorry I couldn't live up to your high standards. Maybe next time. (307 WHP holy madness!).
Vadim (305 WHP), when I saw your guess it was a rare moment. I knew I was going to have to give out the full $50 at that point (I really didn't think anyone would get even close) and that was a sad moment from my wallet.
I can't think of someone else I'd rather have given the money to, so that made it better. =]
coach (303 WHP), the man who understands what stand-alone brings to the table. How does it feel to win now, even though you maybe would have guessed differently if you'd read the description better?
I sort of didn't want to mention this at the end because I don't want to start another dyno chart war but I'll say it anyway. I'm confident in the output I'm making. I have since tested the car against known (stock) quantities and it has performed as one would expect from the dyno graph. Also, the data logs show intake temps really climbing towards redline as the turbo struggles near the end of it's efficiency. There's not much left to make from this T28. In addition to that, I started with a known safe ignition map (based off Enthalpy's standard issue, safe, timing map that he uses to start tuning with) and was knocking. I had to retard timing anywhere from 5-8 degrees in the map to avoid detonation. For those of you who know tuning, this needs no explanation, but for those of you know don't I'll explain. A mixture with more air and fuel will burn faster than one with less. If you have to retard timing, it's because the flame front is reaching the piston top too fast usually due to a quick burn. I was burning so fast, where usually you advance timing from a safe base tune, I had to retard timing. A lot. (I'll post my timing map up later.) This makes me confident I'm making more power with a T28/stock cams/11 psi than possibly anyone else has even thought of. I'm trying to be humble here, but I'm pretty happy with the way things turned out.
How about you?
Last edited by BenFenner
on 2013-02-14
at 16-54-47.