My GS400 = 4.76 0-60mph! G-Tech RR
12-14-09, 05:33 AM
#16
Rock, there is a place in OKC that sells rocks and they have a big scale that they use to measure the weight of their dumptruck b4 and after they fill it with the rocks, i drove up one day and had them weigh my car (for free 
, if you can find some place like that near you that will give you the best weight figures, either that of a scale at a truck stop
, if you can find some place like that near you that will give you the best weight figures, either that of a scale at a truck stop
12-14-09, 10:03 AM
#17
i've weighed my car at a truck stop here in town...it weighs 4050 without me in it, 3/4 tank of gas also. it weighed 4500 with me, my buddy, and a trunk full of camera gear another time when i stopped during a road trip.
as far as the g-tech results....i would say they are BS. in my experiences with a g-tech, they arent very accurate at all, espescially with any kind of wheel spin. the important thing with those is to measure before/after performance. on the same road, with the same launch, and same conditions. basically back to back testing. if you calibrate it for 1 road, then go out and do your "test" on...lets say, a road going downhill...your results will be skewed. i once got a bone stock civic to do a 13.3 in the quarter mile according to a g-tech.....lol
as far as the g-tech results....i would say they are BS. in my experiences with a g-tech, they arent very accurate at all, espescially with any kind of wheel spin. the important thing with those is to measure before/after performance. on the same road, with the same launch, and same conditions. basically back to back testing. if you calibrate it for 1 road, then go out and do your "test" on...lets say, a road going downhill...your results will be skewed. i once got a bone stock civic to do a 13.3 in the quarter mile according to a g-tech.....lol
12-14-09, 10:57 AM
#18
Well this is how I see it. Based on a stock GS4XX doing 0-60mph in 5.9 seconds and a 14.3 second 1/4 mile.
14.3
(0.7) - high stall TC - "up to 0.7 second reduction in 0-60 acceleration", stated on L-tunedparts.com
(0.4) - 3.76 Supra TT LSD - "lower your 0-60 times by nearly half a second (0.4)", stated on L-tunedparts.com
(0.3) - Adding approximately 40whp and 55wtq; various power adders has to cut times by ~ 3/10th's
------
12.9 second 1/4 mile time.
Now, obviously it the above MUST be inflated so let me be conservative...IF and I repeat IF I can get proper traction I feel my car would/could run 13.4's in the 1/4 with a very low 5 second 0-60 time.
Why would this be so off? If my new G-tech results show a best 0-60 time of 5.7X (with a lot of wheelspin) why is it so hard to think the above 13.4 time can't be achieved?
14.3
(0.7) - high stall TC - "up to 0.7 second reduction in 0-60 acceleration", stated on L-tunedparts.com
(0.4) - 3.76 Supra TT LSD - "lower your 0-60 times by nearly half a second (0.4)", stated on L-tunedparts.com
(0.3) - Adding approximately 40whp and 55wtq; various power adders has to cut times by ~ 3/10th's
------
12.9 second 1/4 mile time.
Now, obviously it the above MUST be inflated so let me be conservative...IF and I repeat IF I can get proper traction I feel my car would/could run 13.4's in the 1/4 with a very low 5 second 0-60 time.
Why would this be so off? If my new G-tech results show a best 0-60 time of 5.7X (with a lot of wheelspin) why is it so hard to think the above 13.4 time can't be achieved?
12-16-09, 02:39 PM
#19
Well this is how I see it. Based on a stock GS4XX doing 0-60mph in 5.9 seconds and a 14.3 second 1/4 mile.
14.3
(0.7) - high stall TC - "up to 0.7 second reduction in 0-60 acceleration", stated on L-tunedparts.com
(0.4) - 3.76 Supra TT LSD - "lower your 0-60 times by nearly half a second (0.4)", stated on L-tunedparts.com
(0.3) - Adding approximately 40whp and 55wtq; various power adders has to cut times by ~ 3/10th's
------
12.9 second 1/4 mile time.
Now, obviously it the above MUST be inflated so let me be conservative...IF and I repeat IF I can get proper traction I feel my car would/could run 13.4's in the 1/4 with a very low 5 second 0-60 time.
Why would this be so off? If my new G-tech results show a best 0-60 time of 5.7X (with a lot of wheelspin) why is it so hard to think the above 13.4 time can't be achieved?
14.3
(0.7) - high stall TC - "up to 0.7 second reduction in 0-60 acceleration", stated on L-tunedparts.com
(0.4) - 3.76 Supra TT LSD - "lower your 0-60 times by nearly half a second (0.4)", stated on L-tunedparts.com
(0.3) - Adding approximately 40whp and 55wtq; various power adders has to cut times by ~ 3/10th's
------
12.9 second 1/4 mile time.
Now, obviously it the above MUST be inflated so let me be conservative...IF and I repeat IF I can get proper traction I feel my car would/could run 13.4's in the 1/4 with a very low 5 second 0-60 time.
Why would this be so off? If my new G-tech results show a best 0-60 time of 5.7X (with a lot of wheelspin) why is it so hard to think the above 13.4 time can't be achieved?
also i ran my gs400 at the track....many claim these cars to be low 14 second cars stock.....my car ran 15.0 with intake, exhaust, safc tuned with wideband. granted im running with 285/30/20's and 3 piece wheels which isnt the lightest combo.....even still a 15.0 with mods, is a far cry from the stock claims of low 14's. yes im at 2500ft of elevation, and my 60' times were 2.3x which really isnt that bad. i was hoping for an honest 14.2, 13.9 and was highly disapointed with consistant 15.0's.
i also just looked at the 1/4 mile leaderboard on here and cant help but notice the cars that are running low 13's are nitrous'd and supercharged. the supercharged car has the same mods as you, minus headers but plus a rmm supercharger.
Originally Posted by klyntchgs4
"i started out with just srt intake, pi t/c and the rmm lsd (3:76 gears)...wasn't satisfied - picked up the rmm supercharger - running 13.2's at 104 mph (best dyno was 400 to the wheels - average was around 380)..."
not bashing on you at all...im just saying, those things arent accurate unless you do the things i said in my previous post. they are good for comparing before and after improvements, on the same road, same conditions, no spining at all, etc etc.
12-16-09, 11:56 PM
#20
Driver School Candidate
Join Date: Sep 2009
Location: wa
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
i am basing my remarks off of real world experience, and research that i have done on here. like i said, ive played with the gtech and its never been accurate. i actually ran a nitrous'd integra down the track with the gtech installed...gtech said i ran a 12.4 and the track said i ran a 13.0
also i ran my gs400 at the track....many claim these cars to be low 14 second cars stock.....my car ran 15.0 with intake, exhaust, safc tuned with wideband. granted im running with 285/30/20's and 3 piece wheels which isnt the lightest combo.....even still a 15.0 with mods, is a far cry from the stock claims of low 14's. yes im at 2500ft of elevation, and my 60' times were 2.3x which really isnt that bad. i was hoping for an honest 14.2, 13.9 and was highly disapointed with consistant 15.0's.
i also just looked at the 1/4 mile leaderboard on here and cant help but notice the cars that are running low 13's are nitrous'd and supercharged. the supercharged car has the same mods as you, minus headers but plus a rmm supercharger.
he is running the times your g-tech is claiming, and dyno's 100whp more than you.....unless he has 500lbs of dead bodies in his trunk, i think the g-techs numbers are wrong
not bashing on you at all...im just saying, those things arent accurate unless you do the things i said in my previous post. they are good for comparing before and after improvements, on the same road, same conditions, no spining at all, etc etc.
also i ran my gs400 at the track....many claim these cars to be low 14 second cars stock.....my car ran 15.0 with intake, exhaust, safc tuned with wideband. granted im running with 285/30/20's and 3 piece wheels which isnt the lightest combo.....even still a 15.0 with mods, is a far cry from the stock claims of low 14's. yes im at 2500ft of elevation, and my 60' times were 2.3x which really isnt that bad. i was hoping for an honest 14.2, 13.9 and was highly disapointed with consistant 15.0's.
i also just looked at the 1/4 mile leaderboard on here and cant help but notice the cars that are running low 13's are nitrous'd and supercharged. the supercharged car has the same mods as you, minus headers but plus a rmm supercharger.
he is running the times your g-tech is claiming, and dyno's 100whp more than you.....unless he has 500lbs of dead bodies in his trunk, i think the g-techs numbers are wrong
not bashing on you at all...im just saying, those things arent accurate unless you do the things i said in my previous post. they are good for comparing before and after improvements, on the same road, same conditions, no spining at all, etc etc.
Thats why I stay away from the track...it's always a disappointment.
12-17-09, 05:19 AM
#21
i am basing my remarks off of real world experience, and research that i have done on here. like i said, ive played with the gtech and its never been accurate. i actually ran a nitrous'd integra down the track with the gtech installed...gtech said i ran a 12.4 and the track said i ran a 13.0
also i ran my gs400 at the track....many claim these cars to be low 14 second cars stock.....my car ran 15.0 with intake, exhaust, safc tuned with wideband. granted im running with 285/30/20's and 3 piece wheels which isnt the lightest combo.....even still a 15.0 with mods, is a far cry from the stock claims of low 14's. yes im at 2500ft of elevation, and my 60' times were 2.3x which really isnt that bad. i was hoping for an honest 14.2, 13.9 and was highly disapointed with consistant 15.0's.
i also just looked at the 1/4 mile leaderboard on here and cant help but notice the cars that are running low 13's are nitrous'd and supercharged. the supercharged car has the same mods as you, minus headers but plus a rmm supercharger.
Quote:
Originally Posted by klyntchgs4
"i started out with just srt intake, pi t/c and the rmm lsd (3:76 gears)...wasn't satisfied - picked up the rmm supercharger - running 13.2's at 104 mph (best dyno was 400 to the wheels - average was around 380)..."
he is running the times your g-tech is claiming, and dyno's 100whp more than you.....unless he has 500lbs of dead bodies in his trunk, i think the g-techs numbers are wrong
not bashing on you at all...im just saying, those things arent accurate unless you do the things i said in my previous post. they are good for comparing before and after improvements, on the same road, same conditions, no spining at all, etc etc.
also i ran my gs400 at the track....many claim these cars to be low 14 second cars stock.....my car ran 15.0 with intake, exhaust, safc tuned with wideband. granted im running with 285/30/20's and 3 piece wheels which isnt the lightest combo.....even still a 15.0 with mods, is a far cry from the stock claims of low 14's. yes im at 2500ft of elevation, and my 60' times were 2.3x which really isnt that bad. i was hoping for an honest 14.2, 13.9 and was highly disapointed with consistant 15.0's.
i also just looked at the 1/4 mile leaderboard on here and cant help but notice the cars that are running low 13's are nitrous'd and supercharged. the supercharged car has the same mods as you, minus headers but plus a rmm supercharger.
Quote:
Originally Posted by klyntchgs4
"i started out with just srt intake, pi t/c and the rmm lsd (3:76 gears)...wasn't satisfied - picked up the rmm supercharger - running 13.2's at 104 mph (best dyno was 400 to the wheels - average was around 380)..."
he is running the times your g-tech is claiming, and dyno's 100whp more than you.....unless he has 500lbs of dead bodies in his trunk, i think the g-techs numbers are wrong
not bashing on you at all...im just saying, those things arent accurate unless you do the things i said in my previous post. they are good for comparing before and after improvements, on the same road, same conditions, no spining at all, etc etc.
don't you think that it is a bit odd that a GS4XX cannot get any quicker than a 13.2 second 1/4 mile with almost 400whp!!!???
I mean C'mon...this is RIDICULOUS! What could be the reasoning behind this? Is it a lazy-shifting, crappy transmission?400whp is almost 500hp at the crank! There are TONS of Mercedes AMG models that run high 12's NO PROBLEM with their 469hp (crank) supercharged V8 AND they weight HUNDREDS of pounds MORE!!!
Also, look at the stock IS350. They are 306hp (crank) and probably dyno around 270whp...they are about 300lbs lighter than the GS and only with that amount of power they are capable of running 13.2's in the 1/4 mile. What else am I missing or NOT understanding? The ONLY thing left is just to think that the GS4XX's transmission is a HUGE POS!
Even torquestats.com MUST be wrong with my car then (seems pretty on point with others though). When I enter my figures for my car (using around 4000 lbs) it says I should be around a 13.5 second 1/4 mile car. Now, this would SOUND right on paper basing it off of results from other cars such as the IS350. I make about 10whp more but probably 40wtq more also...however the IS350 is about 300lbs lighter so I would think a 13.2 for it and a 13.5 for my GS4XX would be accurate. But now, turn to real world and it looks like I can barely get a 13.9 second 1/4 mile based on real world results from boosted GS4's. What gives with our cars?
Again, I am not trying to make my car a sports car. I am just trying to find out what the biggest culprit is and change it to make the car quicker. The powerplant is GREAT, the weight is so-so (not terrible for a mid-size 4dr), it MUST be the transmission then.
Last edited by Rock-a-Lex; 12-17-09 at 05:23 AM.
12-17-09, 06:58 AM
#22
GREAT INFO from OLD threads!
Check this out...see post #3. Menegene didn't have headers or the Neo AND had 200 lbs of stereo in the trunk...13.79 second 1/4 mile.
https://www.clublexus.com/forums/per...-your-car.html
Another...see post #2. RMMGS4 didn't have headers or the Neo either (at the time) BUT had the valve body upgrade and achieved a 5.2 second 0-60 run!
https://www.clublexus.com/forums/per...60-low-5s.html
...interesting stuff! Also, after reading MANY old threads many people claimed that traction always became a HUGE PITA with the addition of the PI TC where some actually got a slower 0-60 and 1/4 mile time than stock! One member actually went out and bought drag radials and THEN his 0-60 and 1/4 mile time went down by 0.8 seconds!!!
Check this out...see post #3. Menegene didn't have headers or the Neo AND had 200 lbs of stereo in the trunk...13.79 second 1/4 mile.
https://www.clublexus.com/forums/per...-your-car.html
Another...see post #2. RMMGS4 didn't have headers or the Neo either (at the time) BUT had the valve body upgrade and achieved a 5.2 second 0-60 run!
https://www.clublexus.com/forums/per...60-low-5s.html
...interesting stuff! Also, after reading MANY old threads many people claimed that traction always became a HUGE PITA with the addition of the PI TC where some actually got a slower 0-60 and 1/4 mile time than stock! One member actually went out and bought drag radials and THEN his 0-60 and 1/4 mile time went down by 0.8 seconds!!!
Last edited by Rock-a-Lex; 12-17-09 at 07:11 AM.
12-17-09, 08:02 AM
#23
Driver
iTrader: (4)
Join Date: Oct 2009
Location: al
Posts: 188
Likes: 0
Received 0 Likes
on
0 Posts
You're getting the power to the wheels with your dyno results so I wouldn't blame the trans.
Also:
IS350 curb weight: 3527
GS400 curb weight: 3693
The poster with the 20s, some things to think about:
Wheel/tire weight: heavier wheel/tires that don't just add static weight, but more importantly rotational weight
Gearing: The larger OD of that combo would negatively affect your gearing in a dragrace.
Suspension: Can the vehicle transfer weight as well as a stock car?
Add'l vehicle weight: If you have any, not just wheels/tires, but stereo equip. fat chicks? Generally speaking every 100lbs is 1/10 sec
Dyno tuned with WB: If it was an initia dyne vs. load bearing. Most inirtia machines use a drum weight in the 2400-3200 lb range, none of which will apply a correct load on a 3900 lb car, (loaded with a driver no stereo equip, heavy whls/tires, fat chicks) so even if it was tuned "perfectly" w/o a correct load and never street tuned then there is a good chance its yanking timing too if these engines have knock sensors?
Temp/Altitude/Track conditions/Tire design and condition/Traction...
So depending on the situation described at the dragstrip, I could see some slow times, not as dissappointing though if you know why or what you could change to get your goals.
For more info. on dynos check out www.SECdyno.com and read up on the FAQ section. The heavier the vehicle, or if the vehicle is turbocharged and relies on load to spool, the more important the right tuning equipment is needed.
Rock-A-Lex: I think you'll just need to take it to the track to settle this one.
Also:
IS350 curb weight: 3527
GS400 curb weight: 3693
The poster with the 20s, some things to think about:
Wheel/tire weight: heavier wheel/tires that don't just add static weight, but more importantly rotational weight
Gearing: The larger OD of that combo would negatively affect your gearing in a dragrace.
Suspension: Can the vehicle transfer weight as well as a stock car?
Add'l vehicle weight: If you have any, not just wheels/tires, but stereo equip. fat chicks? Generally speaking every 100lbs is 1/10 sec
Dyno tuned with WB: If it was an initia dyne vs. load bearing. Most inirtia machines use a drum weight in the 2400-3200 lb range, none of which will apply a correct load on a 3900 lb car, (loaded with a driver no stereo equip, heavy whls/tires, fat chicks) so even if it was tuned "perfectly" w/o a correct load and never street tuned then there is a good chance its yanking timing too if these engines have knock sensors?
Temp/Altitude/Track conditions/Tire design and condition/Traction...
So depending on the situation described at the dragstrip, I could see some slow times, not as dissappointing though if you know why or what you could change to get your goals.
For more info. on dynos check out www.SECdyno.com and read up on the FAQ section. The heavier the vehicle, or if the vehicle is turbocharged and relies on load to spool, the more important the right tuning equipment is needed.
Rock-A-Lex: I think you'll just need to take it to the track to settle this one.
12-17-09, 09:29 AM
#24
I agree with all your points but one question...
don't you think that it is a bit odd that a GS4XX cannot get any quicker than a 13.2 second 1/4 mile with almost 400whp!!!??? I mean C'mon...this is RIDICULOUS! What could be the reasoning behind this? Is it a lazy-shifting, crappy transmission?
400whp is almost 500hp at the crank! There are TONS of Mercedes AMG models that run high 12's NO PROBLEM with their 469hp (crank) supercharged V8 AND they weight HUNDREDS of pounds MORE!!!
Also, look at the stock IS350. They are 306hp (crank) and probably dyno around 270whp...they are about 300lbs lighter than the GS and only with that amount of power they are capable of running 13.2's in the 1/4 mile. What else am I missing or NOT understanding? The ONLY thing left is just to think that the GS4XX's transmission is a HUGE POS!
Even torquestats.com MUST be wrong with my car then (seems pretty on point with others though). When I enter my figures for my car (using around 4000 lbs) it says I should be around a 13.5 second 1/4 mile car. Now, this would SOUND right on paper basing it off of results from other cars such as the IS350. I make about 10whp more but probably 40wtq more also...however the IS350 is about 300lbs lighter so I would think a 13.2 for it and a 13.5 for my GS4XX would be accurate. But now, turn to real world and it looks like I can barely get a 13.9 second 1/4 mile based on real world results from boosted GS4's. What gives with our cars?
Again, I am not trying to make my car a sports car. I am just trying to find out what the biggest culprit is and change it to make the car quicker. The powerplant is GREAT, the weight is so-so (not terrible for a mid-size 4dr), it MUST be the transmission then.
don't you think that it is a bit odd that a GS4XX cannot get any quicker than a 13.2 second 1/4 mile with almost 400whp!!!???
I mean C'mon...this is RIDICULOUS! What could be the reasoning behind this? Is it a lazy-shifting, crappy transmission?400whp is almost 500hp at the crank! There are TONS of Mercedes AMG models that run high 12's NO PROBLEM with their 469hp (crank) supercharged V8 AND they weight HUNDREDS of pounds MORE!!!
Also, look at the stock IS350. They are 306hp (crank) and probably dyno around 270whp...they are about 300lbs lighter than the GS and only with that amount of power they are capable of running 13.2's in the 1/4 mile. What else am I missing or NOT understanding? The ONLY thing left is just to think that the GS4XX's transmission is a HUGE POS!
Even torquestats.com MUST be wrong with my car then (seems pretty on point with others though). When I enter my figures for my car (using around 4000 lbs) it says I should be around a 13.5 second 1/4 mile car. Now, this would SOUND right on paper basing it off of results from other cars such as the IS350. I make about 10whp more but probably 40wtq more also...however the IS350 is about 300lbs lighter so I would think a 13.2 for it and a 13.5 for my GS4XX would be accurate. But now, turn to real world and it looks like I can barely get a 13.9 second 1/4 mile based on real world results from boosted GS4's. What gives with our cars?
Again, I am not trying to make my car a sports car. I am just trying to find out what the biggest culprit is and change it to make the car quicker. The powerplant is GREAT, the weight is so-so (not terrible for a mid-size 4dr), it MUST be the transmission then.
like i said before, i knew i was going to be slower than what my car "should" run, because of the elevation (not friendly to n/a cars) and the 20's. i really wanted to get back to the track on some drag radials borrowed from a friends supra, but i have narrowed my problems down to my stock tq converter. because of that, i havent made it back to the track since spring. its my daily driver and the converter is acting up, no need to beat on it anymore.
its my honest opinion that its the transmission ecu and the long 3rd & 4th gears that hurt our 1/4 times. my car flat out falls on its face on the big end of the track. (i suppose thats expected on a 4k lb car lol) if only i could get a higher redline and shorten 3rd and 4th without messing with the rear end (effectively shortening 1st and 2nd which i do not want) that way i could keep my 20's on and still pull decent times at the track. transmission gearing is just as important as making hp (more so in certain situations) when trying to go fast. something that is just not currently possible with our cars without spending more than the price of the car on parts lol
once work picks up more and i have some money to spend on things like tq converter, drag radials, and forced induction....i would love to do some quarter mile testing and see what really makes these cars get up and go. because i agree that these cars should be on par with a lot of other sport luxury sedans.
12-17-09, 09:35 AM
#25
Lexus Champion
I always make CERTAIN before making any performance runs that there are NO fat chicks in my car
While I have generally found my GTech Pro Competition model (same as RR) to give reliable numbers it is not an absolutely flawless device. It is a GREAT tool and used with the free downloadable software PASS gives data that is not available on any dyno pull or drag strip slip.
If Rock has an Iphone with the drag race app that seems fairly accurate. Going to the track is also very good data.
When I first got my GTech in 2002 I took it to the track and it read too quick and too fast but consistent. GTech released new software which I downloaded and it appears much more comparable to actual drag strip times. I have not checked since my software upgrade.
While I have generally found my GTech Pro Competition model (same as RR) to give reliable numbers it is not an absolutely flawless device. It is a GREAT tool and used with the free downloadable software PASS gives data that is not available on any dyno pull or drag strip slip.
If Rock has an Iphone with the drag race app that seems fairly accurate. Going to the track is also very good data.
When I first got my GTech in 2002 I took it to the track and it read too quick and too fast but consistent. GTech released new software which I downloaded and it appears much more comparable to actual drag strip times. I have not checked since my software upgrade.
12-17-09, 09:45 AM
#26
wow after reading about mean-gene's times i wonder if he had a nitrous bottle in the trunk! that guy was pulling off times and trap speeds that forced induction/nitrous guys are running....i think when he said he had a "factory freak" as they say, he was understating it lol
12-17-09, 09:50 AM
#27
I always make CERTAIN before making any performance runs that there are NO fat chicks in my car
LMAO!!!!!!
If Rock has an Iphone with the drag race app that seems fairly accurate. Going to the track is also very good data.
i have used the dynolicious program as well, since its gps based, i have found it works pretty well...although i havent used it at the track, i have used it on cars that have been to the track....usually accurate within a few tenths....i must point out this is on cars that dont have traction issues, or cars that run drag radials on the street. traction is still a factor.
When I first got my GTech in 2002 I took it to the track and it read too quick and too fast but consistent.
that has also been my experience, and thats why i say its a good tool for doing before and after tests because of the consistancy
LMAO!!!!!!
If Rock has an Iphone with the drag race app that seems fairly accurate. Going to the track is also very good data.
i have used the dynolicious program as well, since its gps based, i have found it works pretty well...although i havent used it at the track, i have used it on cars that have been to the track....usually accurate within a few tenths....i must point out this is on cars that dont have traction issues, or cars that run drag radials on the street. traction is still a factor.
When I first got my GTech in 2002 I took it to the track and it read too quick and too fast but consistent.
that has also been my experience, and thats why i say its a good tool for doing before and after tests because of the consistancy
12-17-09, 10:48 AM
#28
I was thinking of removing my stereo equip from my trunk and re-locating my battery to the trunk (also with a lighter one like an Optima red top). So effectively I will save 60lbs off the nose of the car and 120lbs off the rear BUT adding 35lbs to the rear (new battery). Net result will be about 150lbs of total savings...but of this 25lbs lighter in the rear.
I will do some runs this weekend when I take my stereo out. I will let some air out of my tires as well; I think I am running around 40 PSI. Perhaps I will re-locate the battery in a month or so also...
I will do some runs this weekend when I take my stereo out. I will let some air out of my tires as well; I think I am running around 40 PSI. Perhaps I will re-locate the battery in a month or so also...
Last edited by Rock-a-Lex; 12-17-09 at 10:59 AM.
12-17-09, 10:58 AM
#29
You're getting the power to the wheels with your dyno results so I wouldn't blame the trans.
Also:
IS350 curb weight: 3527
GS400 curb weight: 3693
Even closer in weight than I thought...even making the outcome more mind-boggling. That a 270whp car weighing 3527 is capable of 13.2's and a 280whp car weighing 3693 is only capable of 13.8's. 170lbs does NOT offset .6 seconds in the 1/4 mile.
The poster with the 20s, some things to think about:
Wheel/tire weight: heavier wheel/tires that don't just add static weight, but more importantly rotational weight
Gearing: The larger OD of that combo would negatively affect your gearing in a dragrace.
Since a larger OD is worse for a dragrace then the 4.08 gears in the IS350 should hurt it badly versus my 3.76 gears. What am I missing?
Suspension: Can the vehicle transfer weight as well as a stock car?
Add'l vehicle weight: If you have any, not just wheels/tires, but stereo equip. fat chicks? Generally speaking every 100lbs is 1/10 sec
My wheels ar 2-pc 19" forged wheels around 29lbs w/30 lbs tires. 275's in the rear...just stereo in the trunk...no fat chicks. lol
Dyno tuned with WB: If it was an initia dyne vs. load bearing. Most inirtia machines use a drum weight in the 2400-3200 lb range, none of which will apply a correct load on a 3900 lb car, (loaded with a driver no stereo equip, heavy whls/tires, fat chicks) so even if it was tuned "perfectly" w/o a correct load and never street tuned then there is a good chance its yanking timing too if these engines have knock sensors?
It was dyno tuned on a dyno dynamics (4wd dyno)
Temp/Altitude/Track conditions/Tire design and condition/Traction...
Traction has been a bit ch for me.
So depending on the situation described at the dragstrip, I could see some slow times, not as dissappointing though if you know why or what you could change to get your goals.
For more info. on dynos check out www.SECdyno.com and read up on the FAQ section. The heavier the vehicle, or if the vehicle is turbocharged and relies on load to spool, the more important the right tuning equipment is needed.
Rock-A-Lex: I think you'll just need to take it to the track to settle this one.
Also:
IS350 curb weight: 3527
GS400 curb weight: 3693
Even closer in weight than I thought...even making the outcome more mind-boggling. That a 270whp car weighing 3527 is capable of 13.2's and a 280whp car weighing 3693 is only capable of 13.8's. 170lbs does NOT offset .6 seconds in the 1/4 mile.
The poster with the 20s, some things to think about:
Wheel/tire weight: heavier wheel/tires that don't just add static weight, but more importantly rotational weight
Gearing: The larger OD of that combo would negatively affect your gearing in a dragrace.
Since a larger OD is worse for a dragrace then the 4.08 gears in the IS350 should hurt it badly versus my 3.76 gears. What am I missing?
Suspension: Can the vehicle transfer weight as well as a stock car?
Add'l vehicle weight: If you have any, not just wheels/tires, but stereo equip. fat chicks? Generally speaking every 100lbs is 1/10 sec
My wheels ar 2-pc 19" forged wheels around 29lbs w/30 lbs tires. 275's in the rear...just stereo in the trunk...no fat chicks. lol
Dyno tuned with WB: If it was an initia dyne vs. load bearing. Most inirtia machines use a drum weight in the 2400-3200 lb range, none of which will apply a correct load on a 3900 lb car, (loaded with a driver no stereo equip, heavy whls/tires, fat chicks) so even if it was tuned "perfectly" w/o a correct load and never street tuned then there is a good chance its yanking timing too if these engines have knock sensors?
It was dyno tuned on a dyno dynamics (4wd dyno)
Temp/Altitude/Track conditions/Tire design and condition/Traction...
Traction has been a bit ch for me.
So depending on the situation described at the dragstrip, I could see some slow times, not as dissappointing though if you know why or what you could change to get your goals.
For more info. on dynos check out www.SECdyno.com and read up on the FAQ section. The heavier the vehicle, or if the vehicle is turbocharged and relies on load to spool, the more important the right tuning equipment is needed.
Rock-A-Lex: I think you'll just need to take it to the track to settle this one.
12-17-09, 01:04 PM
#30
Lexus Champion
don't you think that it is a bit odd that a GS4XX cannot get any quicker than a 13.2 second 1/4 mile with almost 400whp!!!???
I mean C'mon...this is RIDICULOUS! What could be the reasoning behind this? Is it a lazy-shifting, crappy transmission?400whp is almost 500hp at the crank! There are TONS of Mercedes AMG models that run high 12's NO PROBLEM with their 469hp (crank) supercharged V8 AND they weight HUNDREDS of pounds MORE!!!
There is a HUGE power under the curve difference between the positive displacement supercharged (PS) 5.5 liter AMG and a centrifugal supercharged (CS) 4 liter Lexus. The CS doesn't start making boost until 2500+rpm and it doesnt reach full boost until redline. Conversly, the PS makes boost off idle and makes peak boost for more or less the entire RPM range. The huge advantage of the much larger engine under full boost gives a significant torque advantage at nearly every RPM point below peak power.
Also, look at the stock IS350. They are 306hp (crank) and probably dyno around 270whp...they are about 300lbs lighter than the GS and only with that amount of power they are capable of running 13.2's in the 1/4 mile. What else am I missing or NOT understanding? The ONLY thing left is just to think that the GS4XX's transmission is a HUGE POS!
Even torquestats.com MUST be wrong with my car then (seems pretty on point with others though). When I enter my figures for my car (using around 4000 lbs) it says I should be around a 13.5 second 1/4 mile car. Now, this would SOUND right on paper basing it off of results from other cars such as the IS350. I make about 10whp more but probably 40wtq more also...however the IS350 is about 300lbs lighter so I would think a 13.2 for it and a 13.5 for my GS4XX would be accurate. But now, turn to real world and it looks like I can barely get a 13.9 second 1/4 mile based on real world results from boosted GS4's. What gives with our cars?
Make CERTAIN you have solid 93 octane gas in the tank and drive the car aggressively prior to going to the track. The ECUs seem to try to maximize economy and emissions when driven slowly and the trannys shift early. With some aggressive driving the engines get livelier and the trannys shift later.
PRACTICE your driving at the track. Do not worry about the supercharged times you have seen as those cars are not running optimized.