Is-F supercharger
#46
Unless I'm missing something, the dyno above shows an increase of 21.8 rwhp and similar tq increase with the mods listed from the 'before' stock dyno.
#48
Maybe I'm not making myself clear.......I'm not speaking about gains from the exhaust modification. I'm talking about drivetrain loss to the wheels from stock. 84 hp sounds like a lot....and I've seen the IS-F putting down closer to 350 to the wheels. Again, what are you guys not getting?
Last edited by DaveGS4; 11-24-08 at 06:19 PM. Reason: Removed personal info posted, if you want to discuss it use PM
#49
8speed,
OK, let me try to explain. A chassis dyno measures the power at the rear wheels of your car. It basically figures out what the mechanical (and other) loss is through the drivetrain and records what the power is at the rear wheels. That's why people typically refer to the results as rear wheel horsepower and rear wheel torque
The 417 hp that you are quoting is the hp measured at the crank (right at the engine, when it's out of the car) by the manufacturer.
The 333 RWHP on the dyno chart above is the stock rear wheel horsepower of a 417 hp IS-F on a dyno. It ultimately shows the drivetrain loss through the transmission, drive belts, condition of lubricants, mass of rotating parts etc and gives the results of actually getting the power to the ground. That 84 HP difference represents the loss in a typical stock IS-F on the dyno. In most Lexus cars the drivetrain loss is about 20% (and this dyno proves that out). The loss on a stickshift car is typically less.
How you should be reading that dyno is a stock IS-F like yours makes 333 rear wheel horsepower. So if you wanted to work backwards you could calculate the 333 rwhp stock IS-F by taking rwhp divided by 80% to take into account the drivetrain loss. (333/.8 = 416.25 hp). The IS-F tested with the modifications made 354.8 rwhp so using the same formula that's 443.5 hp, a decent increase.
There are a lot of other factors including weather, temperature and a big difference in the way different brands of chassis dynos measure. The best way to measure what increases you get from modifications is to do it same day, same dyno... as close to the same conditions that the baseline (before) dyno is taken
Hope this helps. Loads of information out there if you google this stuff.
OK, let me try to explain. A chassis dyno measures the power at the rear wheels of your car. It basically figures out what the mechanical (and other) loss is through the drivetrain and records what the power is at the rear wheels. That's why people typically refer to the results as rear wheel horsepower and rear wheel torque
The 417 hp that you are quoting is the hp measured at the crank (right at the engine, when it's out of the car) by the manufacturer.
The 333 RWHP on the dyno chart above is the stock rear wheel horsepower of a 417 hp IS-F on a dyno. It ultimately shows the drivetrain loss through the transmission, drive belts, condition of lubricants, mass of rotating parts etc and gives the results of actually getting the power to the ground. That 84 HP difference represents the loss in a typical stock IS-F on the dyno. In most Lexus cars the drivetrain loss is about 20% (and this dyno proves that out). The loss on a stickshift car is typically less.
How you should be reading that dyno is a stock IS-F like yours makes 333 rear wheel horsepower. So if you wanted to work backwards you could calculate the 333 rwhp stock IS-F by taking rwhp divided by 80% to take into account the drivetrain loss. (333/.8 = 416.25 hp). The IS-F tested with the modifications made 354.8 rwhp so using the same formula that's 443.5 hp, a decent increase.
There are a lot of other factors including weather, temperature and a big difference in the way different brands of chassis dynos measure. The best way to measure what increases you get from modifications is to do it same day, same dyno... as close to the same conditions that the baseline (before) dyno is taken
Hope this helps. Loads of information out there if you google this stuff.
Last edited by DaveGS4; 11-24-08 at 06:51 PM.
#50
So the IS-F on Joe Z's dyno run lost 84 hp or 333 to the rear wheels? My point again for the 1000th time is that number seems low. How are you guys missing what I'm trying to say.
I understand perfectly how a dyno works. Again, what am I missing?
And I didn't know it took two mods to battle the 8speed. I must be moving up in the world!
Classic PM by the way......do as you say not as you do I guess?
http://www.dragtimes.com/Lexus--IS-F-Dyno-Sheets.html
I understand perfectly how a dyno works. Again, what am I missing?
And I didn't know it took two mods to battle the 8speed. I must be moving up in the world!
Classic PM by the way......do as you say not as you do I guess?
http://www.dragtimes.com/Lexus--IS-F-Dyno-Sheets.html
Last edited by 8speed; 11-24-08 at 06:43 PM.
#51
I'm not "battling" anything; I just responded to review a reported post and saw some grossly incorrect information being posted by you.
You can read my edits in the post above, hope that helps you better understand what you're missing.
You can read my edits in the post above, hope that helps you better understand what you're missing.
#53
I don't know the brand of the dyno that SP engineering has, so can't comment for sure but from the math it looks pretty much in line with Lexus' OEM crank claims. Every vehicle will measure slightly different as well. From the factory I've seen bone stock GS400 models have as much as a 20 hp difference for same year, same car.
#55
I don't know the brand of the dyno that SP engineering has, so can't comment for sure but from the math it looks pretty much in line with Lexus' OEM crank claims. Every vehicle will measure slightly different as well. From the factory I've seen bone stock GS400 models have as much as a 20 hp difference for same year, same car.
1. I wasn't discounting gains from exhaust mod
2. I understand the difference between numbers
3. My point was I thought the "TO THE WHEELS" hp numbers seemed low on JOE Z's dyno runs.
That's an hour of my life I wish I had back........
#56
Again, I'm discounting the exhaust mod numbers.........but the baseline "TO THE WHEELS" numbers put down.
#57
If you'll look at the link you posted, there are four dynos posted and two of them are ~ 333rwhp. Sounds like Joe's posted dyno is a pretty reasonable number given the evidence. The HP swing in others could be hotter OEM cars, modifications, weather, different reading dynos, etc etc
1) 357.00*# 345.00 Dynojet Lexus IS-F 2008 Cole
2) 357.00*# 345.00 Lexus IS-F 2008 Cole (duplicate)
3) 344.22*#+ 324.31 DynoJet Lexus IS-F 2008 CrazyMPG
4) 333.20*#+ 318.60 DynoJet Lexus IS-F 2008 NA
5) 332.50# 330.27 DynoJet Lexus IS-F 2008 gcollier
I'm not sure what you're saying here 8speed... you're saying I insulted you ? Please send me a PM with an explanation.
1) 357.00*# 345.00 Dynojet Lexus IS-F 2008 Cole
2) 357.00*# 345.00 Lexus IS-F 2008 Cole (duplicate)
3) 344.22*#+ 324.31 DynoJet Lexus IS-F 2008 CrazyMPG
4) 333.20*#+ 318.60 DynoJet Lexus IS-F 2008 NA
5) 332.50# 330.27 DynoJet Lexus IS-F 2008 gcollier
I'm not sure what you're saying here 8speed... you're saying I insulted you ? Please send me a PM with an explanation.
Last edited by DaveGS4; 11-24-08 at 07:15 PM.
#58
Thank you for your insights. As you can see, it doesn't take insults and flaming PM's to get your point across! And you can see now what I have been trying to say in here for hours.
1. I wasn't discounting gains from exhaust mod
2. I understand the difference between numbers
3. My point was I thought the "TO THE WHEELS" hp numbers seemed low on JOE Z's dyno runs.
That's an hour of my life I wish I had back........
1. I wasn't discounting gains from exhaust mod
2. I understand the difference between numbers
3. My point was I thought the "TO THE WHEELS" hp numbers seemed low on JOE Z's dyno runs.
That's an hour of my life I wish I had back........
What you WANT to say is Joe Z is artificially posting low numbers for his baseline. If you didn't want to say this then you wouldn't be bringing it up in every thread you could possibly squeeze it in.
Find a way to say it without acting like kid in high school.
And for my 2 cents... the numbers do seem low.. one of the lowest I've seen, although I have no idea how many miles were on the car, how old the oil was, etc. There are many variables. My car put out 362HP just after the 5k mile oil change.
#60
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From: Under an IS F since 2008
Looks like I missed a little bit of fun... But let me help clarify a few things...
The IS-F from the factory is rated with the following:
- Horsepower (Hp) 416 @ 6,600 RPM
- Torque (lb-ft) 371 @ 5,200 RPM
- Maximum Engine Speed (redline) 6,800 RPM
All Dyno's of the IS-F R&D car we used, were done independently by SP Engineering here in Southern Ca.
- Which means when we go there, we hand them the key & they dyno test the car, while we stand by and watch.
As others have stated, many DYNO testing machines across the USA and abroad will vary in many ways...
Even when the same brand is used.
For example here is "Automobile Magazine's" independent dyno test of the IS-F, from earlier this year..
Seems they achieved 333 Rwhp as well (Rwhp = rear wheel horse power)
The gains we posted for the exhaust, were again approx. 22 rwhp on our R&D IS-F.
I will & do expect that number to vary from other IS-F's and Dyno's across the spectrum.
"8speed", you bring up a somewhat valid question. In the future I recommend you properly post a direct question in the appropriate thread. We have a whole R&D thread dedicated to answering questions that members may have.
Unfortunately, it is not fair to others if you chose to post misinformation in various unrelated threads..
Thank You
- Joe Z
P.S. - Sorry to take this thread further off Topic, but if any other members would like to discuss the dynos or the exhaust, please post in the appropriate thread.
The IS-F from the factory is rated with the following:
- Horsepower (Hp) 416 @ 6,600 RPM
- Torque (lb-ft) 371 @ 5,200 RPM
- Maximum Engine Speed (redline) 6,800 RPM
All Dyno's of the IS-F R&D car we used, were done independently by SP Engineering here in Southern Ca.
- Which means when we go there, we hand them the key & they dyno test the car, while we stand by and watch.
As others have stated, many DYNO testing machines across the USA and abroad will vary in many ways...
Even when the same brand is used.
For example here is "Automobile Magazine's" independent dyno test of the IS-F, from earlier this year..
Seems they achieved 333 Rwhp as well (Rwhp = rear wheel horse power)
The gains we posted for the exhaust, were again approx. 22 rwhp on our R&D IS-F.
I will & do expect that number to vary from other IS-F's and Dyno's across the spectrum.
"8speed", you bring up a somewhat valid question. In the future I recommend you properly post a direct question in the appropriate thread. We have a whole R&D thread dedicated to answering questions that members may have.
Unfortunately, it is not fair to others if you chose to post misinformation in various unrelated threads..
Thank You
- Joe Z
P.S. - Sorry to take this thread further off Topic, but if any other members would like to discuss the dynos or the exhaust, please post in the appropriate thread.
Last edited by Joe Z; 11-25-08 at 10:27 AM. Reason: Made it Rated G