I bought a IX that was tuned for 93 and all I can get around here is 91. I had to detune to remove knock and honestly I'm missing the power badly. I'm looking for some mods that will work well with the lower octane gas.

Current mods:
Cone Intake
TBE (catless)
MBC at 21 psi
Email Tune

Future mods considering:
LICP
GSC S1 cams
FPGreen/Red/White

Thoughts?

 

I went from 93 to 91 when I moved from NJ to CA. I don't feel a big difference in power the car feels the same, even though I am running 1.5 psi less than I would on 93.

Any mod will work, what matters is how your car is tuned with your mods and the octane of gas.

 

+1

 

There aren't mods made specifically for octane ratings. Octane only comes into play with tuning. A tune of 93 to 91 shouldn't make a big enough difference for you to feel. If it is that apparent your first tune was too aggressive or your second tune is too conservative.

 

You will also need to get some injectors and a fuel pump in order to reach higher numbers.. Stock injectors tend to max out fairly quickly. Friend of mine could only reach 295 WHP SAFELY because anything higher than that and the injectors would be nearly maxed out. Injectors and fuel pump are also there for safety margins.

 

Sorry I also, have the Walbro. Stock injectors as far as I know. Is octane limiting as far as boost pressure goes? ie. Is an aftermarket turbo pointless if 21 psi the max. boost that's safe on 91?

 

21 psi from one turbo may be safe while 21 psi from another turbo will be unsafe. Depends on the flow chart read:cfm of any given blower. The stock turbo can easily max out the stock injectors. I've seen crazy high idcs on a stock tune even with a pump. YOU need to talk to whoever tuned your car and work with him on how to get your car back to its old power levels.

 

Ok, so when I see people running let's say an fpgreen at 21 psi it may be delivering more power than a stock IX turbo at 21 psi? Or perhaps it holds boost better to redline?

 

No.. 21 PSI on the stock turbo should be at the same power level as 21 PSI on the FP green. But I believe the FP does hold boost better to redline. Porting of the stock turbo will also give you this effect.

 

Drive to Vancouver, BC. I found some 94 there when I drove up in July

In all seriousness, the S1's are a good cam, but if you're looking for that missing power you may want to go to something more aggressive like the Kelford 272, the GSC S2 or the Cosworth M2. Your idle may not be as smooth, but your smile will be bigger. Springs/retainers would be good insurance at the same time.

 

I haven't lost that much power. Just a bit of that punch in the back feeling. I figured the S1's were good for midrange power for the street and I could keep my stock drivetrain. What about an upgraded LICP? What kind of gains should I expect with cams and LICP and retune?

 

FYI, the Cosi M2's were worth approx 20+whp in the midrange and upper rpms compared to the S1's with the Green on Aby's car. It was pretty significant. That's on an Evo 8.

 

What about with my stock turbo though? Think the S1's might be better for that?

 

Possibly, but I have learned that it's always best to plan ahead. You mentioned that you were going to upgrade to an FP turbo at some point. I am on my 3rd set of cams. Once I get the Cosi M2's, it will be my fourth pair. The Evo Red will be my 3rd aftermarket turbo. See a pattern?

 

Go with the S1's or HKS 264/264. The 264 cams really wake up the stock turbo on 91 octane.

Do you have access to E85 in Canada? THAT's what you really need.