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For your interest, here are a couple of photos for comparison of my '08 JDM GS460 1UR-FSE direct injection engine.
Underneath the cover with the air intake I have the square shaped (not rectangular) filter with the corner cut off if that helps anyone. And where I am pointing implies that this engine has a cam chain not a cambelt given the aluminium covers and not large plastic front covers to the engine. Although I believe all 1UR family engines are cam chain driven?
Default De-Tuned Lexus Motor (MERGED)So I have heard on CL and Youtube and other comments passed by people that the GS460 has the same motor as the LS, but it's "de-tuned". I have found NIL confirmed or factual evidence so far and would like to know where this comes from, and if it is true, what, exactly is done by Lexus to de-tune the GS motor. Is it simply a fuel/ign map, or is it a restricted intake volume, or something else physical? I really would love to know where these comments come from as nothing factual for me is just, well that. I'm not about to stick my car on the dyno (just yet) to see what the numbers actually are vs. an LS.
Does anyone actually know what the difference is that makes the GS supposedly de-tuned? Or ANY differences in the motors between GS & LS? You could look at the factory spec and see lower numbers and just say "ah yea that one is de-tuned", but I want to know what is different if anyone could enlighten me
__________________
2008 GS460 (JDM)
1UR-FSE / URS190
4.6L V8 D4-S Direct
GS460V8 is online now Report Post Edit Quote Multi Quote Quick Reply
Old Today, 04:47 PM
#2 stilande
Driver School Candidate
So like the rest of this thread we are still unsure of the differing numbers, or more to the point, why the differing numbers
We can so far confirm that yes, the JDM GS460 (or at least the 3.2) has the 1UR-FSE which boasts the 390PS and 500nM. From my understanding this is the same as the LS and can see no real reason why the numbers would be lower other than, a different/tamer fuel and ignition map in the GS, and/or tuning it with less aggressive cam numbers. If the TB's are physically the same size in GS vs. LS, then this CANNOT be the reason. My GS has dual pipes almost all the way, but it merges near the centre to rear of the vehicle and breaks out in to two again, which is definitively more of a performance move and is done for further gains for sure.
After talking to a buddy of mine that has done exhaust systems for a very long time, and a great deal in serious performance numbers, my understanding is the true duals won't give you better performance over a system that reduces the volume at some point further down the track and/or balances the two. After all, the gasses are cooler down the far end, so it makes sense when you think about it. Not to mention the firing order and no balance setup... but... Even if we are talking only exhaust and intake at this point, I can't really see honestly how a 50HP odd difference would be made, bringing me back to mapping. I suppose the cams could be a different grind but doubt it given how VVT-iE works, and I would imagine an engine like that would have a lightly differing engine code if that was the case.
I like the theory of Lexus just understating the numbers to keep the flagship looking good, that's not unheard of as someone else has mentioned, but still, I think mapping is the key if the numbers on a dyno are actually different. If two keen members are in to getting their LS's and GS's on to a dyno, who ever said it had it right... Do it on the same dyno on the same day so the baro cal and everything else is the same.
My money is on them being the same, or a fuel/ign/cam map.
So like the rest of this thread we are still unsure of the differing numbers, or more to the point, why the differing numbers
We can so far confirm that yes, the JDM GS460 (or at least the 3.2) has the 1UR-FSE which boasts the 390PS and 500nM. From my understanding this is the same as the LS and can see no real reason why the numbers would be lower other than, a different/tamer fuel and ignition map in the GS, and/or tuning it with less aggressive cam numbers. If the TB's are physically the same size in GS vs. LS, then this CANNOT be the reason. My GS has dual pipes almost all the way, but it merges near the centre to rear of the vehicle and breaks out in to two again, which is definitively more of a performance move and is done for further gains for sure.
After talking to a buddy of mine that has done exhaust systems for a very long time, and a great deal in serious performance numbers, my understanding is the true duals won't give you better performance over a system that reduces the volume at some point further down the track and/or balances the two. After all, the gasses are cooler down the far end, so it makes sense when you think about it. Not to mention the firing order and no balance setup... but... Even if we are talking only exhaust and intake at this point, I can't really see honestly how a 50HP odd difference would be made, bringing me back to mapping. I suppose the cams could be a different grind but doubt it given how VVT-iE works, and I would imagine an engine like that would have a lightly differing engine code if that was the case.
I like the theory of Lexus just understating the numbers to keep the flagship looking good, that's not unheard of as someone else has mentioned, but still, I think mapping is the key if the numbers on a dyno are actually different. If two keen members are in to getting their LS's and GS's on to a dyno, who ever said it had it right... Do it on the same dyno on the same day so the baro cal and everything else is the same.
My money is on them being the same, or a fuel/ign/cam map.
I don't think anybody here has really dove that deep into the differences between the two, at least not outside of this thread. If you're wanting more detailed answers, the guys over at Sector 7 could probably give you a bit of info on what they've discovered along the way. Since there aren't many companies tuning these things, they're probably going to be your best bet. If you're on Facebook, you should join the group, Lexus GS460 Owners, because they're on there and respond frequently. Not sure how interested you'd be, but you could always call up a local dyno and take it in for a couple pulls to see what it puts down. If you do, definitely post up the numbers
So like the rest of this thread we are still unsure of the differing numbers, or more to the point, why the differing numbers
We can so far confirm that yes, the JDM GS460 (or at least the 3.2) has the 1UR-FSE which boasts the 390PS and 500nM. From my understanding this is the same as the LS and can see no real reason why the numbers would be lower other than, a different/tamer fuel and ignition map in the GS, and/or tuning it with less aggressive cam numbers. If the TB's are physically the same size in GS vs. LS, then this CANNOT be the reason. My GS has dual pipes almost all the way, but it merges near the centre to rear of the vehicle and breaks out in to two again, which is definitively more of a performance move and is done for further gains for sure.
After talking to a buddy of mine that has done exhaust systems for a very long time, and a great deal in serious performance numbers, my understanding is the true duals won't give you better performance over a system that reduces the volume at some point further down the track and/or balances the two. After all, the gasses are cooler down the far end, so it makes sense when you think about it. Not to mention the firing order and no balance setup... but... Even if we are talking only exhaust and intake at this point, I can't really see honestly how a 50HP odd difference would be made, bringing me back to mapping. I suppose the cams could be a different grind but doubt it given how VVT-iE works, and I would imagine an engine like that would have a lightly differing engine code if that was the case.
I like the theory of Lexus just understating the numbers to keep the flagship looking good, that's not unheard of as someone else has mentioned, but still, I think mapping is the key if the numbers on a dyno are actually different. If two keen members are in to getting their LS's and GS's on to a dyno, who ever said it had it right... Do it on the same dyno on the same day so the baro cal and everything else is the same.
My money is on them being the same, or a fuel/ign/cam map.
Its a combination of exhaust and headers. GS460 uses the LS460 AWD headers which makes 20 less hp than the RWD LS460. Remember the Gs460 is 342. That leaves 18 hp. That 18 hp is from the true dual exhaust setup on the LS460 while the Gs460 merges into 1 pipe after the 2nd cats then splits into 2.
Its a combination of exhaust and headers. GS460 uses the LS460 AWD headers which makes 20 less hp than the RWD LS460. Remember the Gs460 is 342. That leaves 18 hp. That 18 hp is from the true dual exhaust setup on the LS460 while the Gs460 merges into 1 pipe after the 2nd cats then splits into 2.
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?
the engine tag on the hood of my 2010 US model says 1UR-FSE.
Its a combination of exhaust and headers. GS460 uses the LS460 AWD headers which makes 20 less hp than the RWD LS460. Remember the Gs460 is 342. That leaves 18 hp. That 18 hp is from the true dual exhaust setup on the LS460 while the Gs460 merges into 1 pipe after the 2nd cats then splits into 2.
Interesting, thanks Blaze876! That makes it to 380 but close enough for me to come to justifying the difference I suppose. So headers are the big one... I can't remember but I think someone in CL has already asked the question about fitting those headers to the rear wheel drive GS, or maybe the GSF headers from the 2012 and up can bolt straight up?
Interesting, thanks Blaze876! That makes it to 380 but close enough for me to come to justifying the difference I suppose. So headers are the big one... I can't remember but I think someone in CL has already asked the question about fitting those headers to the rear wheel drive GS, or maybe the GSF headers from the 2012 and up can bolt straight up?
Yeah the headers on the RWd Ls460 is more free flowing than the LS460 AWD. I know someone was trying to get PPE to do headers but they needed atleast 10 people to commit and that didn't happen. The headers from the LS460 RWD can bolt to the engine of the GS460 since they are identical but I think it hits the body of the car....or that is what I heard but not sure.
I can clear this up pretty easily,
The LS460s 1UR-FSE has a dual intake, a 2 to 1 exhaust manifold that is found on the ISF and a true dual exhaust, as well as ECU changes resulting in different AF ratios. This results in decent power output of 380 bhp.
The GS460s 1UR-FSE has a single intake, log type exhaust manifold and the same y-pipe exhaust found in the IS and GS350, as well as ECU changes resulting in a less than optimal AF ratio and the loss of power to 342 bhp.
In the JDM and USDM markets this is the same in all GS460s and why they only make 342 bhp. Easily enough this is all reversible and 400+bhp out of the GS460 is already possible.
Both the GS and LS have 11.8:1 compression ratio and a 2.9 rear differential.
Interesting what Treybo7 mentioned in the other thread here, and now I have some OBD connectivity with a mobile app (Torque) I noticed right away the AFR's were WELL less than optimal. I just said to my mate today I think I know how they have "de-tuned" it, and then jumped on here after not being here for a wee while and noticed this add to the post hahaha. Confirmed, mine is running an average of about 9:1 AFR measured, but only now just thought I should look at the commanded AFR, just to see if was struggling to meet it, or if that is what's being commanded. I was shocked to see how over-fueled it was!
Last but not least,in addition to the GS460 wierd exhaust,any detuning Lexus did,the air intake "scoop" on the GS is pathetic next to the scoop of the LS.The LS is easily thrice as big.
That bigger opening being in a very high pressure part of the car,is feeding air lot more straight and true,before it hits the air filter.
Anyboby know if an ISF intake manifold will bolt right up? The LS600HL uses the same as the 1UR.
09-04-20, 06:23 PM
