My car has currently 43k miles and I was thinking about adding more power to it
I have read that I could upgrade the pulley and change the air intake
Has anyone ever done that or other modifications ? Was it worth it and would it damage the engine ?
Last I'm located in CA would the car pass the CA smog ?

Thanks

 

If your 03’ SV8 only has 43k miles on it, I would personally leave it alone. If you had to sell it in a pinch and you want top dollar for it and they see that a modification was done, you won’t get as much. I know it’s your car, just saying.

I bought a powerhouse 1.5lb pulley and I had to clearance the snout quite a bit but, I was rebuilding it myself. You’ll make a hell of a mess with it on the car unless you pulled the SC off the car and clearance it yourself. Or better yet, send the snout to the machine shop and have them do it right.

The thing is though, if you don’t pass emissions with the smaller pulley, you’ll have to go through the trouble getting your stock one back on.

I have a fair amount of mods done on my 121k mile 03’ SV8 and I’m quite happy with them.

 

I am wrong there are 2 throttle position sensors and 1 mass air flow sensor so this will have to be edited


~In theory the O2 sensors and the mass airflow sensor will keep the injectors in range to pass your emissions test

Your engine may be consuming more intake air but it will be regulated limited to the range of the ECU maps

The limit of your maps would be if you had more mass air flow then the maps presently installed and that would be hard to know the upper limit of your present mass air flow and ECU maps

You can take a return to the ECU voltage signal to compare it to a graph and extrapolate the extended curve

Your present factory MAF sensor value is 0.50 volts DC on the X colored wire at the correct idle speed

This can be seen on page 59

jagrepair.com/images/AutoRepairPhotos/jagxj2003.pdf

Yours may be before or after the 2003.5 split so you would look at this wiring guide page 37

jagrepair.com/images/AutoRepairPhotos/jagxj2003.5.pdf

There are 2 MAF sensors on your intake , one dedicated to the engine ECU and the other one dedicated to the transmission ECU

You may be approaching or into the saturation curve of the factory MAF sensor which has it's own issues in engine regulation

In emissions test at idle it would certainly be within the range of the maps

The only consideration is the boosted air flow from the supercharger at idle

 

The only thing the smaller pulley does is change when the boost comes in upon throttle application. So say 6lbs of boost you were getting at 3000 rpm is now going to be applied around 2200 rpm.
The SC is just an air pump, albeit compressed air, which burns better with more oxygen and thus more HP. So simply your just moving more air at a lower rpm is all.
The only bad part is, your top end max pressure is also moved up, but unless your turning it out on Montana or Nevada open Hwy at 6k, its all good. Not to forget to mention, your ECU regulated at 155 mph...been there..

The application has been done hundreds of times with these SC's. There are different size pulleys out there, stock is 3", a 2.76" (barring manufacturer) is minimal where you won't have to mill the snout to make it fit, a 2.5" you will. A2B can attest to this.

To complicate this some more for your decision, you can also change the lower pulley as well, but its way more expensive. Powerhouse I believe still sells this.

 

I have the upper pulley upgrade from powerhouse UK. I can tell the low end toque gain instantly. later I have installed their updated intercooler.

I got their lower SC pulley but need to figure the time to install.

I also have the cold air intake from Mina and high flow intercooler pump from Bosch

will also do the Pro M MAF upgrade and ported throttle body. ( I got both parts already)

 

I live in ca and have a smaller charger pulley and bigger intake. The pulley itself does not affect the smog check. Every 2 years at smog i have to put the stock airbox and intake pipes on to pass the visual. So save any and all stock parts removed. You will not have to swap pulleys back to stock. Make sure you have the engine cover on at the smog check too

 

So how do you like the upgrades?

 

The only X308’s that have any kind of cover is the naturally aspirated engines. Your S-type R has an engine cover and that air intake tube covers the charger pulley pretty good. Our S/C X308’s don’t have any cover except for the hood! 😁😁 If an under hood inspection is performed, I would imagine an experienced inspector would notice the pulley. Since I don’t live in CA, I can’t give an accurate description on their threshold of pass/fail.

 

thanks forgot this is an x308 car. They do not inspect the pulley anyway. Mostly plug in the scanner and look for intake mods and cats. Here we deal with smog guys and not dmv or dot inspectors so they want you to pass get the money and on to the next

 

i am very happy for all it is worth on the butt dyno. A forum member alexjag has a tune worth investigating too. He is also in ca. i do not have that…. Yet