Engine Comparison: LS460 vs. GS460 w/ engine cover off - Pictures
04-29-09, 11:48 AM
#31
Lead Lap
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What we need is to have a LS460 and GS460 strapped to the same dyno and see what is really there. Manufacturers in the 70s intentionally underated HP on cars for insurance purposes. Maybe Lexus did not want the GS460 to outshine their GS450h?
Maybe the power is there and we don't know it
Maybe the power is there and we don't know it
I have driven both LS and GS. Totally different. The GS is more responsive and any electric car is going to have more bang at the line.
As for the GS 460, there seems to be a little something odd with the car at certain rpms. A little vibration type of thing. That is not there on the GS430. Not sure I like the eight speed trans in the GS460.. I came from the muscle car too and I stuck my noise up sports with an auto trans until I drove the GS. I’m not a fan of automatics, but this one won me over.
04-29-09, 12:48 PM
#33
I don't doubt you.
The investigation has to start with someone who has access to Lexus part numbers. Are the heads, cams, valves, exhaust manifold the same, LS/GS460? I can't imagine that the LS would have a more free-flowing exhaust, but anything is possible I guess. I'll bet that the LS intake system is more about eliminating intake noise than performance. After all, the IS-F is similar to the GS460 design and it manages to extract 416 HP.
The investigation has to start with someone who has access to Lexus part numbers. Are the heads, cams, valves, exhaust manifold the same, LS/GS460? I can't imagine that the LS would have a more free-flowing exhaust, but anything is possible I guess. I'll bet that the LS intake system is more about eliminating intake noise than performance. After all, the IS-F is similar to the GS460 design and it manages to extract 416 HP.
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Leximum (05-27-23)
04-29-09, 02:41 PM
#34
Driver
I meant that the intake runner was similar in design to the IS-F, not that the motors were similar. If a single intake tract can feed the IS-F's 400+ HP, it should not restrict the GS460.
06-01-09, 10:40 AM
#35
Lexus Champion
Ok, old post but...
The dual intake on the LS looks very good to me.
The GS originally had the 300hp 3UZ-FE which most likely had the 1.97" dual pipe exhaust. Looks like Lexus transplanted the 1UR-FSE while keeping at least the 3UZ intake system and probably the UZ exhaust as well. The UR is physically larger than the UZ and that probably required different exhaust manifolds as well.
The intake and exhaust mods required to fit the engine would probably have come with some durability testing. High RPM high power testing with restrictive exhaust could have shown a need to limit power further than the restrictions alone would dictate. This could be done fairly easily with factory tuning mods.
All of the above is educated guessing but reasonable based on the observable and measurable power differences.
Cures? If my guess on the exhaust manifolds is correct it could be tough to change that. S&S did some testing with the 5.7 trucks and found the ECU to be VERY intolerant of manifold changes. Providing a better intake (if in fact better, not just louder or "fancier") is always a good idea. I gained 5rwhp (track measured) with just a cold air mod to my stock LS400. 10rwhp gain is very reasonable on this larger engine. A properly engineered exhaust (after the manifolds) may be good for 10rwhp more. So, halfway there but probably not cost effective.
The dual intake on the LS looks very good to me.
The GS originally had the 300hp 3UZ-FE which most likely had the 1.97" dual pipe exhaust. Looks like Lexus transplanted the 1UR-FSE while keeping at least the 3UZ intake system and probably the UZ exhaust as well. The UR is physically larger than the UZ and that probably required different exhaust manifolds as well.
The intake and exhaust mods required to fit the engine would probably have come with some durability testing. High RPM high power testing with restrictive exhaust could have shown a need to limit power further than the restrictions alone would dictate. This could be done fairly easily with factory tuning mods.
All of the above is educated guessing but reasonable based on the observable and measurable power differences.
Cures? If my guess on the exhaust manifolds is correct it could be tough to change that. S&S did some testing with the 5.7 trucks and found the ECU to be VERY intolerant of manifold changes. Providing a better intake (if in fact better, not just louder or "fancier") is always a good idea. I gained 5rwhp (track measured) with just a cold air mod to my stock LS400. 10rwhp gain is very reasonable on this larger engine. A properly engineered exhaust (after the manifolds) may be good for 10rwhp more. So, halfway there but probably not cost effective.
11-06-19, 09:37 PM
#37
Driver School Candidate
1UR-FSE has direct injection.
At least in the US all the Japanese built 1UR-FSE have direct injection. To see if yours has it look for the mechanical direct injection fuel pump on the back of the head on the driver's side. These are for high pressure fuel delivery that is run by the camshaft. These only come on direct injection engines.
12-10-19, 05:30 PM
#39
Driver School Candidate
I don't believe you can. It has ports for the dierect injectors and I believe the combustion chamber is a different shape. I'm not certain about this; I would have to see them side by side.
12-10-19, 06:44 PM
#40
Instructor
Different heads, two high pressure fuel pumps, fuel rails, ECU, injectors, injector drivers, ECU, probably bottom end (piston/rod/crank) as well - probably reduced compression + combustion chamber not developed for the direct injector spray. Would be cheaper to just supercharge the FE, I guess.
Re: the compression - I think I was looking at parts a while back and the GS had the same bottom end, block and head as the LS, so the compression should be the same. The lower compression was for the FE, I believe.
Re: the compression - I think I was looking at parts a while back and the GS had the same bottom end, block and head as the LS, so the compression should be the same. The lower compression was for the FE, I believe.
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tiguy99 (07-31-20)
08-14-20, 06:24 PM
#42
HOWEVER, Lexus press release still states GS460 has 1UR-FSE, which i now believe is a typo and could explain why I never hear this "infamous" direct injection noise.
Apologies if this is old but just in case it hasn't been covered, I have a 2008 GS 460 with D4S direct injection being the 1UR-FSE engine, it's JDM so maybe that's the difference?
08-31-20, 09:24 PM
#43
Is this the case? Has this been verified? I have been searching for this info which led me to this post, but haven't found anything conclusive. I am currently looking at LS460s and would like a few more simple bolt-on HPs. Coming from an ISF, headers and full exhaust made a huge difference there. I'd be happy with half of that gain here.
09-04-20, 04:30 PM
#44
I'd almost agree there. With an intake like this, IMO I'd imagine a cold air box and enough flow volume to suit the engine would really only give you a maximum of ~15% max. HP increase.
09-04-20, 04:38 PM
#45
lol i would hate to be the guinea pig for everything, to do this right, I'll have to dyno my car before and after the CAI
also, increasing the airflow isn't going to do squat when the ECU isn't properly adjusted for the increase so proper air/fuel ratio will have to be remapped via chip upgrade
also, increasing the airflow isn't going to do squat when the ECU isn't properly adjusted for the increase so proper air/fuel ratio will have to be remapped via chip upgrade
Not that I have seen this ECU's fuel and ignition maps yet but I think I have enough experience here to know this would be the case. There will be plenty of Headroom here for these kinds of mods. As far as air fuel ratio goes, one major job of the ECU is to maintain this by using that fuel map so I highly doubt AFR is going to be out at all over such simple mods as well. Personally I think opening up the exhaust and intake on of the GS460 would be a smashing move without any other expensive necessities.
Last edited by GS460V8; 09-04-20 at 04:47 PM.