Buying On Monday

[0m3n]

Are there any tuners or programmers available to increase the HP on the 250?

Any noticable difference in acceleration between the manual and automatic trans? (I know its the same HP)

[GDixon]

Are there any tuners or programmers available to increase the HP on the 250?

Any noticable difference in acceleration between the manual and automatic trans? (I know its the same HP)

Buy a 350 and skip the nonsense. Just apply the money you save on the add-ons to the 350 or, even better, the F.

[CrunchySkippy]

Buy a 350 and skip the nonsense. Just apply the money you save on the add-ons to the 350 or, even better, the F.

I agree with GDixon. If performance is what you're after, go for the higher performance model(s). Not only will you save money in the long run, but the reliability will be there. An additional 100hp is hard and expensive to achieve through bolt ons or chip upgrades. Nitrous and/or turbos seem to be the obvious upgrades to pickup 100hp on the 250. I don't know that you will find much in the way of research on the availability or impacts of adding these to the stock 250 engine.

I'm content with my 250, however it doesn't sound like you will be happy with the base power. Good luck with your decision either way.

[Knightshade]

An additional 100 hp on the IS250 is -impossible- to achieve short of some completely custom forced induction system that'd cost a ton more than just getting an IS350.

There is no ability whatsoever to change the US Spec factory ECU in the aftermarket on the 2IS.

Note the auto on the 250 gets better mileage than the manual

[Tango]

An additional 100 hp on the IS250 is -impossible- to achieve short of some completely custom forced induction system that'd cost a ton more than just getting an IS350.

There is no ability whatsoever to change the US Spec factory ECU in the aftermarket on the 2IS.

Note the auto on the 250 gets better mileage than the manual

Weakest component on the 250 and 350 which will limit any possible power output and reliability is the aluminim block. The 350's supercharged by TOM's are restricted in power output for that reason. Either get an IS-F or something much better like the new Nissan GT-R if power is your main interest.

[Knightshade]

An additional 100 hp on the IS250 is -impossible- to achieve short of some completely custom forced induction system that'd cost a ton more than just getting an IS350.

There is no ability whatsoever to change the US Spec factory ECU in the aftermarket on the 2IS.

Note the auto on the 250 gets better mileage than the manual

Weakest component on the 250 and 350 which will limit any possible power output and reliability is the aluminim block. The 350's supercharged by TOM's are restricted in power output for that reason. Either get an IS-F or something much better like the new Nissan GT-R if power is your main interest.

I figured the 12:1 compression was a much bigger reason they can't get more than ~50 horsepower out of their supercharger kit...

Jeremy on CL was able to run a 65 shot of N2O on his 350 without issue (and for massively less than the TOMs kit cost, though of course it's not "always on" power)

On US Spec cars the inability to touch the ECU is a major limitation to modding as well.

[Tango]

I figured the 12:1 compression was a much bigger reason they can't get more than ~50 horsepower out of their supercharger kit...

Jeremy on CL was able to run a 65 shot of N2O on his 350 without issue (and for massively less than the TOMs kit cost, though of course it's not "always on" power)

On US Spec cars the inability to touch the ECU is a major limitation to modding as well.

Changing the compression ratio isn't too much of a problem with a piston change, but the block is still going to be the limiter. The ECU limitation isn't just applicable to the US spec.

[smooth1]

Hey Tango, my block is aluminum and I'm not having any trouble getting 900+ hp out of it. Why do you think that is a power limiting issue for this motor?

[Knightshade]

I figured the 12:1 compression was a much bigger reason they can't get more than ~50 horsepower out of their supercharger kit...

Jeremy on CL was able to run a 65 shot of N2O on his 350 without issue (and for massively less than the TOMs kit cost, though of course it's not "always on" power)

On US Spec cars the inability to touch the ECU is a major limitation to modding as well.

Changing the compression ratio isn't too much of a problem with a piston change, but the block is still going to be the limiter. The ECU limitation isn't just applicable to the US spec.

By the time you're swapping internals of the engine you're spending WAY WAY more than it'd cost to just get an IS-F.

And as noted there's plenty of aluminum blocks making crazy horsepower on forced induction

[CrunchySkippy]

And as noted there's plenty of aluminum blocks making crazy horsepower on forced induction

But very likely using iron sleeves in the cylinders on those aluminum blocks. Smooth should be able to add insight to whether or not this is *always* necessary. (But I always thought so.)

[Knightshade]

And as noted there's plenty of aluminum blocks making crazy horsepower on forced induction

But very likely using iron sleeves in the cylinders on those aluminum blocks. Smooth should be able to add insight to whether or not this is *always* necessary. (But I always thought so.)

Actually, my apologies... (and smooth might need to make some since he's the one I was just agreeing with :P) (unless he has a custom made block or something)

the 2JZ-GTE came with an -iron- block

the heads were aluminum though.

There's still aluminum block engines that make high horsepower though... (the LSx line from GM comes to mind, though they have a pretty obvious displacement advantage too, but plenty of folks boost em)

[Tango]

Hey Tango, my block is aluminum and I'm not having any trouble getting 900+ hp out of it. Why do you think that is a power limiting issue for this motor?

Was informed by a reputable tuning company when I suggested a two stage Rotrex S/C may be a good idea. I presumed it was down to web thicknesses. Hope they were wrong but don't fancy blowing mine up proving them right.

We do not get the 350 this side of the pond and I think I told you the IS-F was like $104,000 here. One of the LOC UK guys has imported a TOM's S/C 350 from Japan, but I was exploring buying a slightly used IS350 engine from the US to modify and fit in my 250 shell

[Knightshade]

Hey Tango, my block is aluminum and I'm not having any trouble getting 900+ hp out of it. Why do you think that is a power limiting issue for this motor?

Was informed by a reputable tuning company when I suggested a two stage Rotrex S/C may be a good idea. I presumed it was down to web thicknesses. Hope they were wrong but don't fancy blowing mine up proving them right.

We do not get the 350 this side of the pond and I think I told you the IS-F was like $104,000 here. One of the LOC UK guys has imported a TOM's S/C 350 from Japan, but I was exploring buying a slightly used IS350 engine from the US to modify and fit in my 250 shell

You'll want as much of the 350 as you can get-

the transmission is different for one (and so the ECU will likely not work with the 250 transmisson)

the 350 has VDIM, the 250 does not... so you'll need all the relevant sensors and wiring for that or the ECU will have issues as well.

Here in the US you're looking at somewhere in the 2-5k range to go from 250 to 350 (comparing new car prices) so it makes no sense to try modding a 250 much...the cheapest way to add power is just buy a 350.

You're looking closer to 15-20k to go from a 350 to an IS-F

And I'd suggest that by the time you got done basically replacing all the engine internals to lower compression, designing your own custom engine and fuel management system, and designing the forced induction system, you couldn't add over 100hp to the IS350 for less than that either.

[smooth1]

To answer the question about sleeves, yes, they sleeve the cylinders.

And yes, because I'm going full out, we have gone to another make aluminum block. I can't come out and say what motor I'm using, as we don't want anyone really knowing. It's the only weapon left. (Surprise!) LOL!!! And the best weapon to use is the one nobody knows about.

I think I referred to the GTE block, and that was my typing faster than my brain thinks. Yes, both the GTE and GE blocks are cast iron, and both can be bored and stroked to a 3.4 liter. I had a BC stroker in my second 2JZGE, but it still didn't pull the way I want it to, so we have since scrapped that plan and I'm going another direction.

And as for how much it costs, if your watching your pennies, modding isn't for you. I absolutely agree, if you want power, don't waste your money on modding a 250, just get a 350. It's mostly the ECU and the direct fuel injection system that stops me from being able to do any "reasonable" work to the motor. That and the fact that there isn't anything out there for it. I could have JE make a lower compression piston at 3x's the price and then they have the blue prints to sell everyone else, but why? The truth is, the Is 350 is just not a platform car as the IS 300 was. And even the IS 300 wasn't really a platform car, it just had alot in common with one, and so alot of the parts were already available for it as the Supra had the 2JZGTE already for 10 years.

[Tango]

Hey Tango, my block is aluminum and I'm not having any trouble getting 900+ hp out of it. Why do you think that is a power limiting issue for this motor?

Was informed by a reputable tuning company when I suggested a two stage Rotrex S/C may be a good idea. I presumed it was down to web thicknesses. Hope they were wrong but don't fancy blowing mine up proving them right.

We do not get the 350 this side of the pond and I think I told you the IS-F was like $104,000 here. One of the LOC UK guys has imported a TOM's S/C 350 from Japan, but I was exploring buying a slightly used IS350 engine from the US to modify and fit in my 250 shell

You'll want as much of the 350 as you can get-

the transmission is different for one (and so the ECU will likely not work with the 250 transmisson)

the 350 has VDIM, the 250 does not... so you'll need all the relevant sensors and wiring for that or the ECU will have issues as well.

Here in the US you're looking at somewhere in the 2-5k range to go from 250 to 350 (comparing new car prices) so it makes no sense to try modding a 250 much...the cheapest way to add power is just buy a 350.

You're looking closer to 15-20k to go from a 350 to an IS-F

And I'd suggest that by the time you got done basically replacing all the engine internals to lower compression, designing your own custom engine and fuel management system, and designing the forced induction system, you couldn't add over 100hp to the IS350 for less than that either.

you don't read my posts at all do you? I'm in the UK..we don't get the 350. I paid $66,000 for my 250 and an IS-F (if I wanted one) is $ $104,000 more or less. But after consideration, forget Lexus..the Nissan GT-R is on it's way and a lot more car than the IS-F for the same money.

[Knightshade]

Hey Tango, my block is aluminum and I'm not having any trouble getting 900+ hp out of it. Why do you think that is a power limiting issue for this motor?

Was informed by a reputable tuning company when I suggested a two stage Rotrex S/C may be a good idea. I presumed it was down to web thicknesses. Hope they were wrong but don't fancy blowing mine up proving them right.

We do not get the 350 this side of the pond and I think I told you the IS-F was like $104,000 here. One of the LOC UK guys has imported a TOM's S/C 350 from Japan, but I was exploring buying a slightly used IS350 engine from the US to modify and fit in my 250 shell

You'll want as much of the 350 as you can get-

the transmission is different for one (and so the ECU will likely not work with the 250 transmisson)

the 350 has VDIM, the 250 does not... so you'll need all the relevant sensors and wiring for that or the ECU will have issues as well.

Here in the US you're looking at somewhere in the 2-5k range to go from 250 to 350 (comparing new car prices) so it makes no sense to try modding a 250 much...the cheapest way to add power is just buy a 350.

You're looking closer to 15-20k to go from a 350 to an IS-F

And I'd suggest that by the time you got done basically replacing all the engine internals to lower compression, designing your own custom engine and fuel management system, and designing the forced induction system, you couldn't add over 100hp to the IS350 for less than that either.

you don't read my posts at all do you? I'm in the UK..we don't get the 350. I paid $66,000 for my 250 and an IS-F (if I wanted one) is $ $104,000 more or less. But after consideration, forget Lexus..the Nissan GT-R is on it's way and a lot more car than the IS-F for the same money.

of course I do, hence why I said "here in the US" to show the contrast.

Here the GT-R is probably gonna run around 80k to the 50-60k for the IS-F... odd that Lexus pricing is so out of whack in the UK, but I agree with the pricing you've described the IS isn't much of a choice for you.

[0m3n]

Thanks for the info... picked up a 350 instead. Test drove the ISF and C63 and decided against the lower MPG's... especially for the Merc, which at 6.3 liters is almost as big as the diesel engine I have in my truck

[smooth1]

Thanks for the info... picked up a 350 instead. Test drove the ISF and C63 and decided against the lower MPG's... especially for the Merc, which at 6.3 liters is almost as big as the diesel engine I have in my truck

Congratulations on the new ride! And that is exactly why I got the 350 also. You get 4 doors, decsent gas mileage, and still quick enouph. Not to mention it looks great, gives a great ride, nice interior, and all the toys.