Amber Gramps

Let's just say it's worth it. Some would say that octane does nothing, but then why is it called "race gas"??? here in California we have to blend down or mix 100 and 91. I usually do $40.00 of each. Let's put it this way....91 has no issues.....95 caused whiplash and days of neck pain. I kid you not. So, is 93 octane worth it? I don't know.

TA911-64

Doug,
I'm in NY where I use only 93 octane. I've tried Russell's chip in stock, 91, and 93. I feel very little difference between 91 mode and stock mode (USING 93 OCTANE FUEL). The 93 mode is significantly better in overall performance.
Tom

SMARCUS

Thanks, that's what I figured. 93 it is.

Sean

rusnak

It sounds like the way to go is the mulitboard. Makes no sense to use a straight chip.

Ed Hughes

Exactly.

911vet

My Multiboard is here! WOO HOO!!! Installation scheduled for this weekend. I'm going to Gingerman Raceway on the 26th and 27th. I'll send a full report in time for everyone to order from Russell during his sale.

911vet

Of course, it isn't the octane of the gas that provides more hp... it's the mapping of the chip that does that.

I don't know the specifics of Russell's mapping, but if you run a chip that gains performance through advanced timing and a lean fuel:air ratio, then you want the higher octane gas in the tank to protect your engine from detonations (i.e. knocking).

(ok engine guys, correct me if I'm wrong).

So race gas alone does nothing to improve your hp, it just protects your engine if you're running a chip that is made for performance.

By mapping with the assumption you've got 93 or better in your tank, Russell can give you maximum performance. So if you can keep that level of octane, you can take advantage of it. Keep the octane up and protect your engine from detonations and damage to the pistons.

Ed Hughes

Octane booster is not something to rely on.

rusnak

911vet, I think that is probably correct.

According to this http://en.wikipedia.org/wiki/Motronic there is no knock sensor in our early Motronic cars, which would throw a wrinkle into things. If a knock sensor were active, the higher octane might mean more power.

911vet

I never said higher octane means more power, quite the contrary, I said it does not.

My point was that the higher octane allows the engine mapping to provide more power while the higher octane protects the engine.

I am aware of the limitations of octane booster -- I was just addressing the person considering buying a single 93 chip instead of the multiboard. There could be times when achiveing 93 octane might be an issue (while traveling, etc).

OK - I'm getting out of the conversation now because I can't pretend to be an expert on engine mapping. I'll leave that to Russell

Amber Gramps

So.....We are back to the butt dyno then. :blinking:

(Shannon, got the box yesterday...Hugs and kisses)

911vet

I prefer the butt dyno to the other anyway. Afterall, it's all about how the car makes you feel. I trust Doug... if he says the cat bypass, open airbox, and Russell's chip will put a smile on my face then that's good enough for me.

If you took a Vette or GT3 and tacked on 8 hp, so what? You'd never notice. But on my car, a few hp and a little torque are noticeable. I did nothing but cut a bigger hole in the intake of my 1.9L 4cyl BMW Z3. It transformed the thing. Did it make it into a 3.2L 6cyl BMW Z? Nope. But it sure did make me happy.

I install the chip this weekend. Can't wait.
Thanks, again, Doug.

Ed Hughes

I think rusnak was agreeing with you........

The mention about no knock sensor really refers to IF a car had a knock sensor and the proper engine management system, more power can be derived from higher octane as the engine could adjust to the fuel being used. This is pretty common in today's performance vehicles. Kinda like having an onboard Russell Berry constantly remapping your setup.

For the record, the RB multi chip seems to drive very well in my car. The power is more linear through more of the powerband. It doesn't come on as strong at the higher revs, like the SW chip does. I'll have mine out on the track this weekend at Fontana, so I'll be able to see how it really feels under stress. I can also compare times from my last event there.

Cowhorn

Do you have to remove the driver's seat to do this mod?

rusnak

I really really appreciate the first hand reviews of the RB chip. I recall that Russell basically reported in the Chip Wars thread that he was trying for a more linear usable power curve, and not as much top end as SW.

911Vet, I was agreeing with you, and Ed is correct. I wonder how a person would quantify the butt dyno results? Is there an app for that? ButtLicious maybe?