KahnBB6

iTrader: (5)

Giulio, your IS200 should have the same electrical system as the 2001-2005 IS300 we have in the U.S. If you have a 2JZ-GE in your IS200 then your options would be the factory Denso/OEM 100-Amp alternator (using older 3-phase technology) that is Toyota approved for all JZ engines or you can use an aftermarket upgraded alternator for JZ engines. Additionally, in the U.S. we can also externally modify certain model year OEM Toyota Sequoia and GX470 pickup/SUV alternators for use with JZ engines which are rated at 130-amps and 150-amps.

However if your Europe-market Lexus IS200 has a 1G-FE 2.0L inline-six engine then I am not quite sure what alternative alternator options are available for you. I am afraid we are less familiar with the 1G I-6 engine family here in the U.S. since we never officially got any vehicles with those engines (1G-FE, 1G-GTE, etc.).

However with a factory 90-amp alternator using the old 3-phase technology I can see a situation where you may under certain conditions have some trouble fully recharging your battery when having added extra electrical systems to the car. It would make sense to find a compatible alternator that offers more peak amperage output and better output at idle with newer 6-phase tech.

GiulioTJ

Hello, can I ask you what do you think of these alternator boosters, are they any good?
There is a link!
Thanks
​​​​​​https://zzperformance.com/products/a...oltage-booster

KahnBB6

iTrader: (5)

I don't know anything about those so I can't really comment other than that I have heard of voltage boosters *specifically* for high current draw aftermarket fuel pumps or multiple fuel pumps for extremely high horsepower cars... but for a regular stock engine? I don't recommend it.

In fact, what you DON'T want is too much voltage throughout the car's electrical system and electronics which are all designed around a general DC 12V standard which is regulated by your alternator's voltage regulator. Problems and possible damage can occur if you pump more than the standard voltage through the car's electrical system.

The fuel pump voltage boosting system I mentioned only boosts voltage *specifically* to a high flow/high-current aftermarket fuel pump... not the rest of the car.

Any good alternator will have a good voltage regulator to keep the voltage output consistent. You shouldn't be seeing much more than a consistent 14.2V from a good alternator that isn't being loaded down with too much amperage draw for its amperage rating. If the alternator is an older 3-phase design the amperage output at or near idle (and thus the amount of amps that it can handle at that RPM) will probably be a bit lower.

For instance, the alternator in my 2JZ SC300 is the older 3-phase OEM design and it's rated at only 100 amps. At idle, once the car is up to full temperature (and once the alternator housing and electronics have warmed up as well) I get anywhere between 13.1V, 13.2V to at best 13.5V when the engine is within cruising RPMs. It puts out the full 100 amps when the engine revs higher. This is OK... but it could be better with a newer 6-phase style alternator from a good manufacturer. IF it were rated at more total amperage there probably would be less overall voltage drop at or near idle.

I'm not an electrical engineer and someone who is can surely explain this much better but the gist of it is that a voltage booster device isn't what will solve your issue. What will solve your issue is a compatible alternator from a reputable company (OEM or aftermarket) that offers more than your factory 90-Amp output rating. And preferably with newer 6-phase technology rather than the 3-phase tech your stock alternator undoubtedly has.

Keep in mind that when upgrading to any higher output alternator in any car with any engine you must upgrade to thicker/larger gauge (ie: lower gauge number) alternator ground and alternator charging cables to handle the extra electrical load. And the alternator main fuse underhood needs to be able to rated to handle the new alternator amperage output number or at least very close to it so long as your car's electrical system will not be actually drawing amps from it up to its maximum output rating (ie: you can properly install a 140 Amp alternator with upgraded cables but your car may only draw 100 or 110 Amps... which means you would never actually trigger your car's alternator main fuse with a rating slightly lower than the alternator's max amp capability).

The best thing is to find out what companies offer a new higher output alternator that is compatible with what I presume is a 1G-FE 2.0L I-6 stock engine in your Euro Lexus IS200. Unless I'm mistaken and you actually have a 3S-GE 2.0L or 2JZ-GE 3.0L in your Euro IS200.

SolidJ

Seeing how alternators from other lexus/Toyota vehicles can be used, I'm safe to use a 2000 LS430 alternator in my sc400? Fitment should be fine as the top and bottom bolts for both match.