Ty back from the Dyno

[White97SVT]

Sat was a busy day. I had just gotten that new belltech front swaybar from the Mike Lee GP and need to get that on along with the new KYB Monomax shocks (thanks Morgan for the recomendation). Well before that whole deal started I had an appointment to take the Ty to the Dyno for a baseline # before i started any mods.
Well anyway the truck is all stock other then the ATR catback exhaust on it, and it put down 257awhp and 400lb/ft. All and all i was pretty impressed.
I included graphs also, after looking at the graphs for a little bit i noticed a dip in the curve, I know from lookng at my boost gauge the sometimes the truck fluctuates in boost, what can cause that? how can i get a more constand peak hold?
The truck handles much better with that swaybar on there now. At first we had a little trouble with getting it all lined up but once we got the A-arms bracket bolted in we could kinda pull the bar forward enough the get the other bolts on there (thanks to Rob for the help with the swaybar and shocks). I didn't think it would make that much of a differnce but it did. The truck rides pretty much the same at low speed, but you can feel it more in the corners at high speeds and on the highway with the quick lane changes. Some new KYB Monomax shocks and it's like a completely different machine, the ride is a little more firm but not uncomfortable.

 

[midnightbluS10]

Nice

 

[Ian Turgeon]

with drivertrain losses, hp at the crank:

25% = 343hp
20% = 321hp

 

[turbodog]

That's at stock boost level? Wow! What has it run at the track?

My boost control stabilized dramatically when I replaced the boost control solenoid valve (the solenoid valve on the turbo). I think oil builds up in it and causes it to respond slowly. You might be able to clean it out, but for $15, I recommend a new one.

 

[Vaders Sy]

I got different numbers:

25% drivetrain loss: 321HP
20% " " " " " " : 308HP

 

[White97SVT]

Yeah, that is under stock boost.
The only things done in the engine bay are the 160* thermostat and the hotwired Jabsco IC pump. Neither on of those are hp boosters. I have the ATR SS cat back but still have the stock cat and everything. I wanted to get the baseline becuase i wanted to start doing a few other things to it.

I see that you guys are coming up with some hp #'s at the crank. Is that based on the power put down at the wheels? I see you are taking a % number. I thought that the hp you loose due to drivetrain kinda stays the same. Like if you loose 25hp you will always loose the 25hp no matter what, does it fluctuate with different hp?

What do you guys recommend for getting a more constant 15psi?

 

[jwaller]

better boost control has been discussed for yrs and yrs. search some and you will find more than enough info.

 

[Ian Turgeon]

I got different numbers:

25% drivetrain loss: 321HP
20% " " " " " " : 308HP

your doing your math wrong and adding 25% of 257.

suck 25% out of 343 and you end up with 257

25% of 257 != 25% of 343... believe me i tried to do the math the same way before i cought myself.

yea thats at the crank, drivetrain losses are considered to be a percentage of the total hp. somewhere around 20%-25% from what i can remember.

 

[TYPHUZION]

I got different numbers:

25% drivetrain loss: 321HP
20% " " " " " " : 308HP

your doing your math wrong and adding 25% of 257.

suck 25% out of 343 and you end up with 257

25% of 257 != 25% of 343... believe me i tried to do the math the same way before i cought myself.

yea thats at the crank, drivetrain losses are considered to be a percentage of the total hp. somewhere around 20%-25% from what i can remember.

SYTYArch is correct you need to subtract the drivetrain loss from the crank #.

I see you have my quote in your sig.

 

[Vaders Sy]

You guys are funny.

Here is the equation:

H= Crank HP (What you want to know...Keep this in mind very important)
D1 = Drivetrain loss of 25% or (d1=.25)
D2 = Drivetrain loss of 20% or (d2=.20)
W = Wheel Horsepower (What we DO know)

h = w + (w x d1)

h = w + (w x d2)


Its pretty simple algebra, but if you guys need some help I can explain. In short, you guys are guessing the crank horsepower when in reality that is what you want to find. Therefore, since you want to know crank HP, the above equation is correct.

 

[GEN3Typhoon]

You guys are funny.

Here is the equation:

H= Crank HP (What you want to know...Keep this in mind very important)
D1 = Drivetrain loss of 25% or (d1=.25)
D2 = Drivetrain loss of 20% or (d2=.20)
W = Wheel Horsepower (What we DO know)

h = w + (w x d1)

h = w + (w x d2)


Its pretty simple algebra, but if you guys need some help I can explain. In short, you guys are guessing the crank horsepower when in reality that is what you want to find. Therefore, since you want to know crank HP, the above equation is correct.

Gotta go with Lord Vader on this one boys.

X/1.2 = 253/1
X= 304 (close enough)

 

[rockvillespeed]

100 bucks says our losses are closer to 30%.
beware of numbers generated on a chassis dyno unless the tcc is locked.

 

[AlaskaTy]

Okay, one more way to figure it out:

Take the HP or TQ to the wheels and divide by the % they see.

ie: 257/.75 = 343

For some (like me) this is an easier way to figure it out.

 

[tyndago]

How about not giving a s-hit what it makes at the engine ...

What makes it to the ground , and how fast it runs the 1/4 is the true test of what it makes or does.

Its easy to make a dyno say anything.....

 

[rockvillespeed]

sean speaka the truth.
and, since we cant know our drivetrain losses with any degree of accuracy, wheel numbers really do mean more.
lastly, going up from chassis to crank #'s via math is often far off due to the ,ajor discrepancies in power curves often seen wheel vs crank.
one example - a motor almost never makes peak hp at as high an rpm when installed in-car. often many hundreds lower.

 

[Ian Turgeon]

agreed about actual performance being the deciding factor,

but as far as the equation goes:

h x (1 - d) = W

h x .75 = 257

h = 257/.75
h = 343

if I'm wrong I'm fine with it but I'm not convinced I am.

 

[Vaders Sy]

but as far as the equation goes:

h x (1 - d) = W

h x .75 = 257

h = 257/.75
h = 343

Obviously the math works in that equation, but the point is to find H not W. That is what I was saying. Your solving for the W when are we already know it. Therefore, H needs to be by itself on one side of the equals sign hence, h = w + (w x d)

Math aside, as SyTyArchives stated, performance is how he measures a vehicles power. I couldn't agree more.

 

[smeagol]

You guys are funny.

Here is the equation:

H= Crank HP (What you want to know...Keep this in mind very important)
D1 = Drivetrain loss of 25% or (d1=.25)
D2 = Drivetrain loss of 20% or (d2=.20)
W = Wheel Horsepower (What we DO know)

h = w + (w x d1)

h = w + (w x d2)


Its pretty simple algebra, but if you guys need some help I can explain. In short, you guys are guessing the crank horsepower when in reality that is what you want to find. Therefore, since you want to know crank HP, the above equation is correct.

You know wheel hp, but in your above equations, you are multiplying your wheel hp by a percentage, which doesn't make sense. If you multiplied your CRANK hp by the percentage, you'd be fine.
(make your equation read h = w + ( h x d )

Crank hp = wheel hp + (losses through drivetrain)
crank hp = wheel hp + (crank hp x % lost through drivetrain)
crank hp = 257 hp + ( crank hp x .25 )
C = crank hp, we'll solve for C

C = 257 + .25 C
.75 C = 257
257 / .75 = C
C = 343

Quick test, if you lose 25% through the drivetrain, 75% of power makes it to the pavement. .75 of 343 = 257hp

I feel as Sean does though. Who cares what hp it makes, it's all about the performance. A syty doesn't have good dyno numbers typically, but go to the dragstrip and it'll beat a lot of vehicles down the track.

 

[tyndago]

I feel as Sean does though. Who cares what hp it makes, it's all about the performance. A syty doesn't have good dyno numbers typically, but go to the dragstrip and it'll beat a lot of vehicles down the track.

297 rwhp . 4060 lbs 11.95@113.


You tell me if it makes sense..............

 

[White97SVT]

I feel as Sean does though. Who cares what hp it makes, it's all about the performance. A syty doesn't have good dyno numbers typically, but go to the dragstrip and it'll beat a lot of vehicles down the track.

I thought my truck put down some decent #'s... Typically what did other stock trucks put down. I will let you know how it performs at the track after LVD opens up or when we have our first dragday up there.