Shrapnel19

I have a stock1998 Lexus SC400. I'm looking to start gaining some HP and was hoping to get some help looking for a short ram or cold air intake system. I've been looking around and couldn't find any. Do I need to piggyback with a different year or model?

LeX2K

There is no intake that will give more power than stock don't waste your money. The so called cold air intakes draw HOT air in from the engine bay instead of the original which draw air from outside the engine bay.

KahnBB6

iTrader: (5)

^^ This. The 1998-2000 SC400 with their VVT-i 290hp/300tq engines are the most powerful U.S./Canada SC's in stock form. The factory air box is still your best bet, Shrapnel19. I'm not even aware of an aftermarket "cold" air intake available for the 92-97 SC400's or 98-00 SC400's.

The only time that one of those cone filter intakes makes sense is if you have a force inducted (turbo JZ engine or supercharged/turbo 1UZ) engine. The hot air draw from the engine bay is still a factor even in those applications but intercoolers do help in those cases.

For NA SC's with the 3.0L or 4.0L engines cold air intakes really aren't an improvement over the bone stock intake air box. However you could install a K&N drop in filter if you wish but you will not feel much improvement from it by seat of the pants.

t2d2

iTrader: (8)

If you want a cone filter, it doesn't have to pull in hot engine bay air, but you have to be willing to do a little work on your end and construct a heat shield. I don't see why that's always viewed as a dead end.

KahnBB6

iTrader: (5)

^^ This is true. Isolating the cone filter intake away from hot engine air (mostly separating it from the main cooling fan) can make a difference.

There is also the prefabbed MVP Motorsports Supra MKIV air intake heat shield. I have one of those since I do have a cone filter setup myself (engine is turbo) but I haven’t modified it yet to fit in the SC. It takes a little work to fit our cars and it’s set up for the stock intake pipe layout on MKIV TT’s but it can be made to work with any custom piping I’m sure.

(The only reason I’m not using an OEM air intake box in my car is because keeping cruise control in this configuration doesn’t allow me to due to tight fitment with the SC cruise unit in its stock location).

Shrapnel19

Ok thank you, everyone, for the kind and helpful replies. So I've been looking some more and have found a K&N performance air intake (with a heat shield) for a 1998 Lexus GS400. Now i think i can jurry rig the bastard in. Honestly im going for engine bay looks and sleek desighn in the end so I dont think it can hurt?

Zerodrag

iTrader: (5)

There is the BFI option of modding your stock air box. Not sure if it nets any HP, or if it would be a problem with passing the visual for emissions for some states.

KahnBB6

iTrader: (5)

The BFI mod probably won’t fly in strict smog testing locales like California or NYC. Then again an non CARB approved intake kit for any model+trim vehicle won’t either.

The only mark against the BFI mod that I can think of is during a time of flooding but in that case you wouldn’t want to drive the SC through flooded roads anyway.

It amounts to taking the stock air box and permanently modifying it with three or so open air holes (using little air flow trumpets over them as with ITBs) for more flow onto the flat OEM style air filter inside.

KahnBB6

iTrader: (5)

The GS400 VVT-i has the same engine and transmission as the SC400 VVT-i but the engine bay layout is different. Their cone filter block off setup will likely not fit at all.

The MVP Motorsports cone filter isolator for the MKIV TT still needs a little modification to fit in an SC but it’s nearly right for it given that SC and MKIV engine bays are the same other than a couple of very minor mounting point differences within the same panel shapes.

oldManTan

even if you air filter is completely outside of the engine bay the pipe is hot and "cold air Intakes" do absolutely nothing for performance. larger piping and a bigger throttle body will do more than getting "colder" air, and even then expect 1-3HP. keep the stock air box and get a better flowing drop in air filter and do the BFI mod.

KahnBB6

iTrader: (5)

^^ Exactly.

t2d2

iTrader: (8)

The intake pipe is only hot when idling. Air movement will cool the surface considerably when moving at speed, and there's always the option of insulating it.

oldManTan

there is absolutely no airflow in the engine bay with a stock hood, i have a diagnostics tool and the difference in intake temp between idle and driving in 80 degree weather is 2 degrees Fahrenheit.

t2d2

iTrader: (8)

I was referring to the cool airflow in the pipe, not around it.

If you're seeing that little drop at speeds, there's something funky with your testing procedure or application (e.g., driving under very heavy loads). Some counter-examples:

https://www.challengertalk.com/threa...ratures.29915/
https://www.bimmerforums.com/forum/s...ormal-op-range