F.I.T V's Yella Terra ; L67 Upgrades

[VS CALAIS]

What pulley upgrade are most people running on their Factory L67 S/C V6. Is there a differance between the FIT pulley system and YT.. (Yes i know with the YT unit you must replace the snout). Also FIT have 1.9:1 ratio rockers for inlet and exhaust where as YT have suggested i run their 1.7:1 on inlet and 1.8:1 on exhaust. With the ratio rockers who is right who is wrong , would 1.8:1 be bugger all diff to the 1.9:1 when it comes to flow or not? As i'm planning to run 10-12 psi and upgrade the ratio rockers while im at it.

 

[mattman]

10.5psi has proved to be the best boost to run on 98RON without intercooler, any higher and you get pre-ignition and knock retard. 10psi pulleys are a very common upgraded for this reason. The FIT and Yella Terra upgrades give about the same results, except the FIT kit is much much much cheaper. I THINK the YT snout give more possibility for higher boost, as it runs a smaller snout, but don't quote me on that.

Rockers.. I'll leave that to someone who knows more about it

 

[sixshooter]

The YT snout allows fitting of much smaller pulleys for even higher boost... to do the same with any other pulley system using the standard blower snout requires machining of the snout.

 

[mattman]

Cool.. that's what I had figured. There has to be a reason it costs more.

If you are only planning on running 10psi and not intercooling in the future, I wouldn't worry too much about the YT snout. $1300 odd and a hell of a job to fit it. FIT kit is around $800 and that includes loan of a fitting tool, takes about 1 hour and you can do it yourself with a couple of basic tools.

 

[VS CALAIS]

Looks like FIT seems the way to go not planning on running more than 10.5 psi (well at the moment...) can anyone help out with the ratio rocker question??

 

[mattman]

FIT have run a 1.8:1 set in a car... dynoed and swapped straight to their 1.9:1 set, dynoed again and got 2-3rwkw from memory.

Seems the FIT ones are a little better, but they are just a machined, refurbed stock rocker, whereas the YT ones are brand new never used. Comes down to personal preference, both are around the same $$.

I don't know that much about it, but it only makes sense to me that more lift=more power. (being that more lift means more air in the chamber??, I don't know)

 

[shaggerz]

In case you guys are still interested, I stumbled across a guy on ebay selling a hub and interchangable pulley system for the M90 for the bargain price of $350 including loan of the pulley removal tool. He tells me the hub is stainless steel and the pulley is aircraft alluminium. Other pulleys (any size requested, within reason) are $80.

Sounds like a REALLY cheap way to get that massive power increase to me. I will definitely be investing in this almost as soon as I have got the calais.

 

[sixshooter]

In case you guys are still interested, I stumbled across a guy on ebay selling a hub and interchangable pulley system for the M90 for the bargain price of $350 including loan of the pulley removal tool. He tells me the hub is stainless steel and the pulley is aircraft alluminium. Other pulleys (any size requested, within reason) are $80.

Sounds like a REALLY cheap way to get that massive power increase to me. I will definitely be investing in this almost as soon as I have got the calais.

Yeah I've seen that.

 

[HIROLLA]

Ive read that having 1:9:1 rockers gives the same amount of power (and wear) as a cam upgrade.