GS430 on the Dyno
02-23-04, 01:42 PM
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GS430 on the Dyno
Went to Dyno Day at the local performance shop (JP Importz - a local Club Lexus sponsor) last Sunday. I I was real interested to see how my bare bones stock, still under warranty, 01GS430 would do on the horsepower side. I have owned the car for about six months, having purchased it from Sewell Lexus here in Dallas, who had all the service records, which were unremarkable.
Anyhow, with VSC disengaged and the power setting selected, the car only pulled 230 hp. The manufacturer claims that the horsepower at the engine is 300. Drivetrain loss should be around 20% according to the general rule of thumb. That puts it at 240. Due to the relatively low mileage on the car, and the fact that it runs perfectly, I guessed that it would be around 250.
The Dyno operator (who seemed to know what he was doing, but also admitted that he had not tested a second generation GS before) claimed that the car should be tested in 3rd gear. I did not argue with him at the time, but in retrospect, think now that it should have been tested in 4th with the overdrive locked out. This would have obviously resulted in a little higher top end speed The curve was textbook nice and even with peak HP at around 5800 RPM (I think. The chart is at home). I'm no physics expert, but HP = (Torque X RPM)/5252. If I would have been able to achieve a higher RPM via 4th gear, would not the HP be greater than 230?
Anyone else have any experience in this area?
Anyhow, with VSC disengaged and the power setting selected, the car only pulled 230 hp. The manufacturer claims that the horsepower at the engine is 300. Drivetrain loss should be around 20% according to the general rule of thumb. That puts it at 240. Due to the relatively low mileage on the car, and the fact that it runs perfectly, I guessed that it would be around 250.
The Dyno operator (who seemed to know what he was doing, but also admitted that he had not tested a second generation GS before) claimed that the car should be tested in 3rd gear. I did not argue with him at the time, but in retrospect, think now that it should have been tested in 4th with the overdrive locked out. This would have obviously resulted in a little higher top end speed The curve was textbook nice and even with peak HP at around 5800 RPM (I think. The chart is at home). I'm no physics expert, but HP = (Torque X RPM)/5252. If I would have been able to achieve a higher RPM via 4th gear, would not the HP be greater than 230?
Anyone else have any experience in this area?
02-23-04, 02:05 PM
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Re: GS430 on the Dyno
Originally posted by GS430Ben
Went to Dyno Day at the local performance shop (JP Importz - a local Club Lexus sponsor) last Sunday. I I was real interested to see how my bare bones stock, still under warranty, 01GS430 would do on the horsepower side. I have owned the car for about six months, having purchased it from Sewell Lexus here in Dallas, who had all the service records, which were unremarkable.
Anyhow, with VSC disengaged and the power setting selected, the car only pulled 230 hp. The manufacturer claims that the horsepower at the engine is 300. Drivetrain loss should be around 20% according to the general rule of thumb. That puts it at 240. Due to the relatively low mileage on the car, and the fact that it runs perfectly, I guessed that it would be around 250.
The Dyno operator (who seemed to know what he was doing, but also admitted that he had not tested a second generation GS before) claimed that the car should be tested in 3rd gear. I did not argue with him at the time, but in retrospect, think now that it should have been tested in 4th with the overdrive locked out. This would have obviously resulted in a little higher top end speed The curve was textbook nice and even with peak HP at around 5800 RPM (I think. The chart is at home). I'm no physics expert, but HP = (Torque X RPM)/5252. If I would have been able to achieve a higher RPM via 4th gear, would not the HP be greater than 230?
Anyone else have any experience in this area?
Went to Dyno Day at the local performance shop (JP Importz - a local Club Lexus sponsor) last Sunday. I I was real interested to see how my bare bones stock, still under warranty, 01GS430 would do on the horsepower side. I have owned the car for about six months, having purchased it from Sewell Lexus here in Dallas, who had all the service records, which were unremarkable.
Anyhow, with VSC disengaged and the power setting selected, the car only pulled 230 hp. The manufacturer claims that the horsepower at the engine is 300. Drivetrain loss should be around 20% according to the general rule of thumb. That puts it at 240. Due to the relatively low mileage on the car, and the fact that it runs perfectly, I guessed that it would be around 250.
The Dyno operator (who seemed to know what he was doing, but also admitted that he had not tested a second generation GS before) claimed that the car should be tested in 3rd gear. I did not argue with him at the time, but in retrospect, think now that it should have been tested in 4th with the overdrive locked out. This would have obviously resulted in a little higher top end speed The curve was textbook nice and even with peak HP at around 5800 RPM (I think. The chart is at home). I'm no physics expert, but HP = (Torque X RPM)/5252. If I would have been able to achieve a higher RPM via 4th gear, would not the HP be greater than 230?
Anyone else have any experience in this area?
I think the HP ratings are based on cars with low mileage that run perfectly, so discount that 250HP expectation. There is some documented proof that some engines (BMW, Porsche) actually dyno stronger when they have more mileage on them.
I haven't hit that hp with all my modifications on the dyno yet. Just like any cars, there are some that are stronger out of the box and some that aren't.
What kind of dyno was it? That also makes a big difference. I dynod a good 15% less on a Mustang dyno vs a Dynojet due to the different way it measured HP.
How was your TQ?
02-23-04, 04:00 PM
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The file size for the chart is too big, or I would include it in the reply. Basically, we are looking at 240 ft-lbs of TQ at 4.3 RPM (X1000) and 225 ft-lbs at 5.2 RPM. Drops to 200 ft-lbs at 5.9 RPM. I wish I could attach the chart. Maybe with an email address?
Ben
Ben
02-23-04, 07:00 PM
#4
Originally posted by GS430Ben
The file size for the chart is too big, or I would include it in the reply. Basically, we are looking at 240 ft-lbs of TQ at 4.3 RPM (X1000) and 225 ft-lbs at 5.2 RPM. Drops to 200 ft-lbs at 5.9 RPM. I wish I could attach the chart. Maybe with an email address?
Ben
The file size for the chart is too big, or I would include it in the reply. Basically, we are looking at 240 ft-lbs of TQ at 4.3 RPM (X1000) and 225 ft-lbs at 5.2 RPM. Drops to 200 ft-lbs at 5.9 RPM. I wish I could attach the chart. Maybe with an email address?
Ben
230 sounds about right from my research i've been doing lately... a member dynoed his car ,a gs430 and it did a little more.. i'm going 2 search 4 a sec and post what he did...and how many miles he had
02-23-04, 07:23 PM
#5
ok i found the post his was also pretty brand new and 235 2 the wheels stock and 267 2 the wheels with srt intake and borla exhaust...heres the link 2 the thread..https://www.clublexus.com/forums/sho...ght=borla+dyno
02-24-04, 03:17 AM
#6
From all the info. that I have read and SRT mentioned also the car should be dynoed as close to 1:1 gearing. The GS400/430 gear ratio is :
1st-3.36
2nd-2.18
3rd-1.42
4th-1.00
5th-0.75
I was curious about the difference between 3rd & 4th. I dynoed my 01 GS430 when it had about 2500 miles stock and w/ Borla at about 4500 miles and told them to do it in both gears and This is what I got.:
Stock-2500 miles temp.75 degress
3rd- HP-226.7 TQ-253.3
4th- HP-231.6 TQ-259.1
W/ Borla exhaust 4500 miles temp. 82 degrees
3rd-HP 229,9 TQ-260.9
2runs
4th- HP 232.7 TQ-266.5
4th- HP 233.3 TQ-269.5
All done on Dynojet dyno.
1st-3.36
2nd-2.18
3rd-1.42
4th-1.00
5th-0.75
I was curious about the difference between 3rd & 4th. I dynoed my 01 GS430 when it had about 2500 miles stock and w/ Borla at about 4500 miles and told them to do it in both gears and This is what I got.:
Stock-2500 miles temp.75 degress
3rd- HP-226.7 TQ-253.3
4th- HP-231.6 TQ-259.1
W/ Borla exhaust 4500 miles temp. 82 degrees
3rd-HP 229,9 TQ-260.9
2runs
4th- HP 232.7 TQ-266.5
4th- HP 233.3 TQ-269.5
All done on Dynojet dyno.
Last edited by GILLEXUS; 02-18-05 at 02:05 PM.
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02-24-04, 06:44 AM
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Thanks, I could not get the !@#$@%(!!@# thing to post. I think next time hte dyno is in town, I will run it in 4th gear. Based on the other posts, I will only get another 5 hp or so. I am a little disappointed, but am not going to do anything to boost as my warranty still has 25k miles left.
02-25-04, 08:41 AM
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my 98Gs4 made 235 in 4th on a dynojet
Torque was 246.
You will find that you cannot hammer it in 4th and it not downshift if the RPM is below 4000. Since the GS4 motor has a torque peak at 4000, the peak torque number will not be accurate. You either get an accurate PEAK HP reading and a wrong torque number or two wrong numbers.
You will find that you cannot hammer it in 4th and it not downshift if the RPM is below 4000. Since the GS4 motor has a torque peak at 4000, the peak torque number will not be accurate. You either get an accurate PEAK HP reading and a wrong torque number or two wrong numbers.
01-09-05, 02:05 AM
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Originally Posted by GS430Ben
Thanks, I could not get the !@#$@%(!!@# thing to post. I think next time hte dyno is in town, I will run it in 4th gear. Based on the other posts, I will only get another 5 hp or so. I am a little disappointed, but am not going to do anything to boost as my warranty still has 25k miles left.
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