I have a 1999 4runner w/ 3.4L V6 and 4wd. I am wanting to add performance to it. Here are my two different ideas (if you know of something better, let me know).

Option 1:
TRD S/C
TRD 7th Injector Kit
TRD Headers and Exhaust
Level 10 Valve Body upgrade

Option 2:
TRD S/C
URD S/C Kit
TRD Headers and Exhaust
Level 10 Valve Body upgrade

Basically the only difference between the two is the 7th injector kit vs. the URD kit. The main problem with the S/C's is that they make it run too lean. The 7th injector kit is suppose to correct this problem, correct? The URD S/C kit is suppose to correct this as well, correct? Which would offer a better performance increase? I'm guessing it wouldn't be a good idea to add the 7th injector AND the URD kit. I would think that combining the 7th injector with bigger bosch injectors and a bigger fuel pump would make it run too rich as well as destroying any chances of having decent gas mileage. So, who has testing the URD kit, and the 7th injector, and which gave you better performance?

 

Actually I don't think lean is the problem with the SCs if I remember correctly. The problem is actually the timing being too far advanced at low rpms. You can correct that with the FTC1. If I was adding an SC, that's what I'd run instead of the 7th injector or the URD kit. Of the two, the URD kit is better. There's lots of people that know more about this on the board and they'll chime in and let you know. I've only got a 3.slow .

 

Ag, actually lean is a problem with the 4runners running S/Cs because the fuel system is just not able to keep up with the demand placed on the system by the S/C. This is the high RPM ping people talk about. The second part is the LG/HT ping which gets adjusted for by the FTC1. So you are correct on that part.

Haniblectre, I would go with the second option only because I feel that the 7th injector is more of a bandaid approach (granted the system appears to work fine for people running the S/C). As an engineer I just think Gadget's kit has been better "engineered". Both will work fine.

As for headers I think there are a few cheaper systems out there like Edelbrock and Downey which do just as good a job and look great if you get them ceramic coated. Again search and you will find alot on the board regarding this.

Also I would have IPT do the valve body upgrade since they are cheaper (I think?) and John is a member on the board ("transdude") so he is usually online to help you out if something isn't working quite right. Be sure to pull the negative battery terminal after you install this to reset the computer completely.

 

URD Kit.
I wouldn't get the TRD headers/exhaust. Most have had the "Stainless Steel" rust and look like crap in no time. You may get better results with Downey headers.

 

URD S/C Kit
Its a proven upgrade and excellent instructions to install.All you need is $$$$ for more upgrade.