Hilux 4.0 V6 Free Flow

[jguthrie]

Hi Guys,

Just wondering if anybody has experience with putting a free flow exhaust on the new shape Toyota 4.0 V6?

I am thinking about having this done and have had some input from the local exhaust place. They recommended replacing the pipes after the Catalytic sensors, but before the actual Catalytic Converters, thus removing the converters but keeping the sensors in tact.

Question, is this the correct place to start the conversion or should it not be closer to the engine i.e. just after the branches, or do you need to keep the catalytic sensors in tact?

Taking it from after the branches, would this have any performance gain over taking it after the Cat sensor?

Thanks in advance.

Regards,
John Guthrie
0834475588
john@iwarehouse.co.za
http://www.iwarehouse.co.za

[Scorpion]

Hi, John. I have been considering the same thing on my V6 Fortuner. What I can tell you about freeflows (I've had many done on previous cars) is that to just simply replace them doesn't make sense. The average exhaust shop just simply replaces, without checking what influence it has on your kW and Nm - you might gain some in the higher rev range and you lose some lower down. This is not what you want for offroading!

The best is to take it to a place that dynos the car before and after the fitment and makes sure you get what you want. It normally costs quite a bit more, but it's worth it in the end. Up here in Gangster's Paradise, the best guys are probably Viper Exhausts in Kempton Park. I see they do one for the V6 and it pushes power from 168kW to 189kW and 390Nm to 435Nm. I'm not sure what application it's for, but give them a call and ask them. I don't have their number on me, but will look and also post it here.

Good luck!

[Scorpion]

Just found it! Viper Performance Exhausts: (011) 394 1895

They might not be able to sort you, but they will be able to give you some good advice.

[jguthrie]

Great, thanks for the good feedback - I will give them a call.

[JohanM]

Hi John,

I personally would not change the exhaust on the 4.0 lt, however I might consider removing the cats in the exhaust.

I have found that on the 4.5 EFI Land Cruiser Pickups that I converted in my days at SAC, the branch and Freeflow would only add more noise to the vehicle and on the dyno we could only measure about 1.2-2km on the rear wheels.

The cost involved for increasing that slight bit of more power it was not making sence, and also they tend to blow the manifold gaskets on the branch and downpipe, which added more hassels to a perfect reliable system.

It only works when you do a conversion on a small diameter pipe vehicle ie HIlux 2.2 & 2.4's

The 4.0 Lt's pipe is a semi free flow already with a resonater box to keep the noise very low. It is also big enough and I cant see the benefits of changing the full system on it.

[jguthrie]

Hi Johann,

Thanks for the good advise.

I am going to have a chat with Koosie Swanepoel from Koosie Swanepoel Developments and see he has experienced as he does the whole dyno before and after thing.

Cheers,
John Guthrie
0834475588
john@iwarehouse.co.za
http://www.iwarehouse.co.za

[JohanM]

Hi John,

Its a pleasure, like I said that was then, dont really know about the new vehicle's anymore.... :roll:

Please let me know what the outcome is of your decision as I am very interested to see what the results is when you do decide to change the exhaust on your Hilux.