Hi,

I have heard some good things about the SRT HFI/ECU and am close to buying but I have some questions for those who have had the the SRT on their GS400.

How difficult is the installation? Understand some wiring is necessary. Is it just clip into OEM or you need to splice?

Quality and reliability of the product? Any long-term usage feedback?

Any dealer warranty issues having the SRT HFI/ECU? How easy to take out if I take it to the dealer?

Any problems integrating with engine? (i.e. check engine warning lights, stalling)

How much better gas mileage and where is the gain in HP and torque performance, low, mid high end?

Does it make any additional noises or make the engine louder?

Does the HFI/ECU integrate with the car ECU seamlessly? Any changes needed if I have the L-tuned exhaust?

In general, for someone who keeps a car for a long time, my assumption is an aftermarket intake should prolong engine life due to better efficiency, right?

Thanks,

 

I already ordered HFI/ECU this morning and I will let you know the result once I receive the package.

For intake, it shouldn't be hard. I've done it on bimmer and it was easy.

Regarding the warranty concern, https://www.clublexus.com/vb/showthr...5&pagenumber=2

From what I heard from members, it improves approx. 3 mpg.

All the intakes will increase the noise level under WOT.

 

recently I have received the information from some members, saying we could buy the other intake, which is like Weapon R.... or.. some thing that sucks more air than the SRT ones. and buy the ECU seperately , that way we can program the ECU ourselves, and thus gain more performance... that should be easily put out 50 hp. just a thought tho.

 

Hi Wei,

That's not a good idea . First of all, there is NO WAY you will get 50HP out of just an intake and ECU remap. It is not a Turbo car where you can increase boost pressure and fuel timing. 50 HP is over 15% increase over stock output - that's forced induction territory. The most you can get is probably another plus 5 HP as compared to the SRT package.

Second of all, SRT tuned the piggyback ECU specifically for their intake. Unless you know someone that can tap into the Lexus ECU or reprogram SRT's ECU (which I doubt they will allow) you won't have much success matching the Weapon R intake.

The most difficult part of any forced induction mod on our GS is the ECU. OBDII has basically killed a lot of the crazy mods that you can do here in the US. That's why you see a lot of older Supra's, Z's, and 7's with 600 HP or more because you can easily tap into the ECU. I honestly believe that if someone cracked into the ECU, there will be a FLOOD of turbo and SC kits available for us IMHO.

Anyway, just didn't want to get hopes up too high...sorry for being the killjoy

PS Love your GS430? Bring it over sometime so I can take a look at it...

Brent

 

Wei,

You could purchase Wearpon R's intake for roughtly $300 + shipping, combining with APEXi S-AFC (you can get it for roughly $315 shipped from groupbuycenter). S-AFC gives you the freedom to adjust according to your need. Like Ray said before, nobody has ever put S-AFC in his GS. Theoratically speaking, Weapon R with S-AFC should give a better performance than SRT's HFI/ECU but when you calculate the cost ($625 shipped SRT v.s. at least $615 WeaponR APEXi), keep in mind that you need to take your car in for professional tuning and installation, that nobody knows how much it costs. Will the alternative combo gives you more performance? How much? Will it worth at least another 100, or 200 bucks?

I have a brand new S-AFC on my hand now and even until today, I still couldn't decide whether to go with SRT or the other alternative. Before SRT's package arrives, I still have couple weeks to think about it.

 

PS...

The new intake is much louder because you remove the plastic resonator piece that sits over the side of the engine. This piece acts like the muffler. You have to remove it because it comes as one piece with the stock airbox. I here a gurgling sound now because of that. Very domestic-y which I love!

Brent

 

Just to add to RA's comments...

XSEngineering is one of few places I know that tunes Apexi products...They are the best, but I don't think they really have experience with the package we are thinking about (Apexi plus Weapon R).

BTW, tuning costs $100 / hr so you might be looking at a couple of hours...if they would even do it. You also run the risk of leaning out your engine - not good on that new GS430 motor.

Brent

 

-Dennis

The Apexi one you are talking about is exactly what I plan to get........ I think somehow I can get these two for around 500~550 range. The reason I wanna get the ECU is what you mention, ability to reprogram it. yeah but we will need to go to a fine tuner to get this to work. BTW Swift racing costs 800 + for the intake. so that's 200+ more than the custom combination tho.

 

Everyone is talking about XSEngineering. If I decide to go with S-AFC, I will definitely do the installation there.

Wei,

SRT is having this groupbuy thing, $625 shipped and I just ordered it this morning at 7:30 (I have class starts at 8 damn it). If you go with SRT, you can do the installation yourself and like Bliu said, they have dyno proof and some CL members behind them. If they are no good, SRT wouldn't even survive in the market. $800 for intake/ecu is too expansive in my taste but $625 shipped and guarantee hp/torque gain, I can accept that.

 

Sense we are talking about intakes. Any intake will give you more HP. Add a intake to a 4 liter and you get 7-8 HP so of course you'll get more from a V8 right
I have the Swift intake but still would like one that I can make adjustments on. As for the HP gain, you will get more with the APEXI/Intake than with Swift but still its all up to you and want you want.
As for tuning the APEXI> there are many shops in LA itself that can tune it. I really wouldn't worry about that at all.
The hardest thing about the GS is the ECU and cracking it but someone will soon. All and all its up to you so let us know which one you have desided on

 

Adding any intake may only give you a very small increase in HP or none at all. Just adding extra air changes the fuel/air ratio from the conservative 14.5:1. Once the engine managment controls start sensing this lean out, it will start to change the timing and injector duration to keep everything perking along for as long as it can. After that you will have a fullblown lean out condition and you lose HP and create all kinds of problems. Make sure the shop you choose to tune your APEXI has experience on the GS ecu engine mapping. At $100/hr, the time spent getting it right is on their side and I think it will take quite a few hours. If they get it wrong, you might have a difficult time getting them to pony up the $15k:eek: for a new motor. That's the scary part. I'm sure someone will get the APEXI figured out for the GS. I'm not so sure if I would use my baby as the lab rat without a bunch of written guarantees in hand first.

Just my .02

 

thanks for the input, I will give XS engineering a call tomorrow, I am willing to let my car to be the first to have successful AFC/Weapon R Intake System combination. I am pretty sure the result would be quite amazing. I wil make sure i have all the written works!

 

Keep us posted.

 

I think I probably need to hear what kind of noise and the db level on a car with the HFI/ECU before I buy it.

Is there anyone in the Los Angeles area who has a GS with the HFI/ECU installed?

 

I work in Santa Monica and live in Torrance. Let me know if you are interested in hearing it on a GS400...

Brent