Why are GS400 so slow?
10-10-03, 12:59 PM
#1
Lexus Test Driver
Thread Starter
Why are GS400 so slow?
Thought that would catch everyone's eye!! At any rate I've posted earlier about deciding between a GS400 and a Jaguar XJR to replace my high mileage (160,000) Lincoln Mark VIII. I think I'm going the GS route. 95% sure at this point. I REALLY like the forged bits in the GS400 engine. This engine will handle nitrous or a blower no problem. It is a stout and VERY reliable piece.
What is the bottleneck in the GS400 1/4 mile performance?? Even with your basic mods, it seems like running 13's is a bit tough. My Mark is only very mildly tuned......with just an 80mm mass air, pulleys, dyno tuned chip and gears and it ran well into the 13's. This was with only 241RWHP. (and at a cost of less than $1000). I'm guessing that the bottleneck is the gears?? I was running 4.10 gears. Gearset for the Mark are only a couple hundred bucks, and the remaining parts plentiful and cheap (for those that don't know, the Mark VIII has the N/A Mustang Cobra engine..it had it a full 3 years before they used it in the Mustang. It shares the rear end with Mustang, more or less. And most aftermarket engine parts from a Cobra go right on.) Are there any gear sets for the GS, short of the entire LSD?? I have plenty of DOHC V8 experience, so I know that a good TQ and gears REALLY make these types of engines come alive. Especially the gears. These engines usually lack down low, and the gears cure this big time!!
So where can gears be had? I'm still learning about the GS400 aftermarket suppliers. L-Tuned, Swift..who else? Thanks again for helping this GS400 newb out. All comments appreciated...even the flames!! LOL Thanks!! ~R
What is the bottleneck in the GS400 1/4 mile performance?? Even with your basic mods, it seems like running 13's is a bit tough. My Mark is only very mildly tuned......with just an 80mm mass air, pulleys, dyno tuned chip and gears and it ran well into the 13's. This was with only 241RWHP. (and at a cost of less than $1000). I'm guessing that the bottleneck is the gears?? I was running 4.10 gears. Gearset for the Mark are only a couple hundred bucks, and the remaining parts plentiful and cheap (for those that don't know, the Mark VIII has the N/A Mustang Cobra engine..it had it a full 3 years before they used it in the Mustang. It shares the rear end with Mustang, more or less. And most aftermarket engine parts from a Cobra go right on.) Are there any gear sets for the GS, short of the entire LSD?? I have plenty of DOHC V8 experience, so I know that a good TQ and gears REALLY make these types of engines come alive. Especially the gears. These engines usually lack down low, and the gears cure this big time!!
So where can gears be had? I'm still learning about the GS400 aftermarket suppliers. L-Tuned, Swift..who else? Thanks again for helping this GS400 newb out. All comments appreciated...even the flames!! LOL Thanks!! ~R
10-10-03, 01:05 PM
#2
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great post, i had the same delma a year ago, i was think about getting the jag aswell, well i went with the lexus cuz its more of a sports car once you lower it and add some mods. jag mods are very expensive and hard to come buy rather then the lex.
about the bottleneck question - only advise i can say is you should of just bought the gs430 if you want to run 13's out the gate.
about the bottleneck question - only advise i can say is you should of just bought the gs430 if you want to run 13's out the gate.
10-10-03, 02:00 PM
#3
Originally posted by martialart
about the bottleneck question - only advise i can say is you should of just bought the gs430 if you want to run 13's out the gate.
about the bottleneck question - only advise i can say is you should of just bought the gs430 if you want to run 13's out the gate.
Doc
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10-10-03, 04:29 PM
#9
Lexus Test Driver
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Maybe, the bigger question is why is your Lincoln so fast?
What's your trap speed in the 1/4 mile. At 100mph with 4100lbs of car, fuel, and driver, you are making around 330hp at the crank. What are gears worth? about 1-3/10th of a second?
What's your trap speed in the 1/4 mile. At 100mph with 4100lbs of car, fuel, and driver, you are making around 330hp at the crank. What are gears worth? about 1-3/10th of a second?
10-10-03, 05:00 PM
#10
Forum Administrator
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RRocket,
I'm not doing any research to confirm my memory here, but stock gears for a GS400 are 3:23. You can put a differential out of a Supra TT that is geared at 3:76 (full pumpkin replacement) and has the side benefit of being a Torsen LSD unit. RMM also sells this same rear end.
The GS300 has a 3.916 gear (as mentioned above) in it that I've never heard about anyone switching out in a GS400.... LexPro put one in his SC430 and it's working great.
One primary issue with the GS, however, is that *some* people have is the rev limiter on the GS. Even with the 3.76 gears some of the members hit the rev limiter when under WOT which just kills the power and shift. I expect the GS3 gears would exacerbate that situation.
I'm not doing any research to confirm my memory here, but stock gears for a GS400 are 3:23. You can put a differential out of a Supra TT that is geared at 3:76 (full pumpkin replacement) and has the side benefit of being a Torsen LSD unit. RMM also sells this same rear end.
The GS300 has a 3.916 gear (as mentioned above) in it that I've never heard about anyone switching out in a GS400.... LexPro put one in his SC430 and it's working great.
One primary issue with the GS, however, is that *some* people have is the rev limiter on the GS. Even with the 3.76 gears some of the members hit the rev limiter when under WOT which just kills the power and shift. I expect the GS3 gears would exacerbate that situation.
Last edited by DaveGS4; 10-10-03 at 05:03 PM.
10-10-03, 05:05 PM
#11
Lexus Champion
The Mark VIII had 280 hp when they came out- to be honest, I have no idea why that sled is running n the 13s, even with the mods you have done! Congratulations!
Not sure if I would call the GS4 slow- the guy in the Carrera 4 I raced on the freeway yesterday was pretty pissed when we both hit it at 75mph and he couldn't gain an inch on me until I backed out at about 125mph (indicated- my car runs 20" wheels, so the speedo is underdriven).
I recently ran a Carrera 2 Cabriolet with my Dad and my brother in the car- I passed him after starting behind him from a 10 mph roll-on. The guy in the 3.0 Z3 (5-speed) that I smoked last night wasn't smiling, either....
For the GS, I'd run gears with an LSD and a torque converter, perhaps with an intake & exhaust. If you really want to haul @ss, why not just buy a Z06? Great bang for the buck, even if the build quality isn't terrific... If I want to go fast, I use my '85 MR2 (with intercooled ball-bearing turbo, sticky tires, full suspension, etc.).
Not sure if I would call the GS4 slow- the guy in the Carrera 4 I raced on the freeway yesterday was pretty pissed when we both hit it at 75mph and he couldn't gain an inch on me until I backed out at about 125mph (indicated- my car runs 20" wheels, so the speedo is underdriven).
I recently ran a Carrera 2 Cabriolet with my Dad and my brother in the car- I passed him after starting behind him from a 10 mph roll-on. The guy in the 3.0 Z3 (5-speed) that I smoked last night wasn't smiling, either....
For the GS, I'd run gears with an LSD and a torque converter, perhaps with an intake & exhaust. If you really want to haul @ss, why not just buy a Z06? Great bang for the buck, even if the build quality isn't terrific... If I want to go fast, I use my '85 MR2 (with intercooled ball-bearing turbo, sticky tires, full suspension, etc.).
Tell me more about the MR2!
10-10-03, 06:49 PM
#13
Lexus Test Driver
Thread Starter
I have the LSC model which had 290HP. Remember this engine is very de-tuned and under-stressed. My dyno tuned chip alone netted 22 RWHP and 24RWTQ. With my stock 3.27 gears and similar mods, all Mark VIII run 14.0-14.2. Toss in the 4.10s, and the car REALLY comes alive 13.7-13.9. These DOHC engines need gears like that. Our club has done many tests, and going from our 3.27 to a 3.55 or a 3.73 didn't make a huge difference, on the street or on the track. But the 4.10 are astounding. They really keep the car in the meat of the power, and give it a much needed punch down low. I suspect the same would happen to the GS. While the Supra gears make the car better, I'm willing to bet the GS3 gears make this car REALLY hammer!! (I don't have a LSD in the Mark...no real need unless you live at the track.). Why buy a Z06? I want a comfortable ride, not one that feels like a lumber wagon. And why spend huge coin on a pushrod V8 when I can have a DOHC? I love the revvy DOHC. For what it's worth, we have several Mark VIII in our club that run easy 12's. Just the usual mods and Nitrous. I think a GS with these same mods and gearing could run 12's too. I think I'm onto something with the gearing. Seriously no one has tried the GS3 gears in the GS4?? I think this will be the hot ticket....
10-10-03, 07:56 PM
#14
Lexus Test Driver
I ran 13.9 with intake/ecu and TC. Not major major mods, but modded nevertheless.
I haven't ran with the new setup yet, but will soon. I expect with the right conditions to be hitting deep into the 13's for sure.
I haven't ran with the new setup yet, but will soon. I expect with the right conditions to be hitting deep into the 13's for sure.