JoesC5

While on vacation I was driving through West Virginia on I-79 in my Z06. needed gas so I(and another Corvette) stopped at a major retailer. I filled my car with 91 octane premium(and paid the premium price) as did the C5. As soon as I pulled back on the interstate, I knew something was amiss. We were in the mountains and the car really was down on power and when I checked my instantaneous gas mileage, it had dropped off significantly as to before filling up.

I'm positive that I ended up with 87 even though I thought I was getting premium(and I paid for premium). I took it easy, downshifted to minimize luging the engine when going uphill, etc, and when I was down to 3/4 tank I stopped and topped off with premium. Again, when I got down to 3/4 tank, I stopped and topped off with premium. I did this several more times.

I didn't end up with a tank full of 87 because I was an idiot. Now what damage might I have done to my engine if I had a supercharger with 600whp and I started beating on it as soon I pulled out of the station. This is what GM has to contend with when designing an engine.

Theta

That would be a terrible situation - I only use specific gas brands, but I can see what you're saying.

Bad gas can, indeed, make **** hit the fan.

JoesC5

can you spell EXXON?

I normally use only Conoco as it is a Top Tier retailer and they sell 93 octane ethanol free gas locally. If only I could pull up to any station in the US and buy it..........

Theta

Man, I wish we had Conoco around here. We barely have Shell. Thankfully, BP/Exxon pretty much went out of business here - still a few Mobil stations around.

QT dominates this market, and their 93 isn't terrible.

DOUG @ ECS

Nailed it yet again. Fuel is 99% of the time the cause of engine failure in a boosted application.

I can't stress enough the use of a basic octane additive for pump gas cars. Not to be used for additional power, but as the safety net for poor grade fuel. Tune it without, use and abuse the car with. Especially if it is going to be road raced, then I recommend a good dose of 100 octane when your there. Can't fix that problem for $30-$50 afterwards, but you can prevent it for that.

Theta

I usually use Techron fairly often, but I need to get into the habit of using an octane booster (especially on boost).

I'm guessing Torco?

DOUG @ ECS

Amsoil makes one, VP just came out with one, Torco is good, any of the major brands work.

Keep in mind that gas starts to break down very quickly, so letting a car sit for a couple of months is the same as getting bad gas. It just gives that extra edge to combat that.

JoesC5

Same around here as Mobil, Exxon and BP gone as is QT. QT is a Top tier gasoline so if you can get it in 93, that's not to bad, even though it has ethanol in it.

I use pure-gas.org to look for stations when I'm on vacation, in my Z06 or my supercharged Mercedes.

Blackdevil77

All the gas over here has ethanol in it. How's BP gas? Around here, it's seems very good. I've been putting it in all my cars.

I'm enjoying this reading this discussion. Keep it comin' I'm learning over here

Theta

Hmm, if the product '104+' isn't crap, that looks like a bargain at under $5 a tank...

DOUG @ ECS

I have been told it does not work that well, but I have never personally tested it back to back like I have the three I listed, so I have nothing to back that statement like I do with the three I listed.

E.A.

I have actually seen a LOT more messed up H/C installs, then blowers.

People putting in wrong push rods, not TQ'ing down things like rockers correctly, to big of cams smashing valves, etc.

Bolting on a blower, attaching a belt, and loading a tune pretty easy.
Tearing into a motor, making sure everything is right, and re-doing a massive amount of tuning.... pretty big operation.

But yes, anything that is modified can break. However working at a dealership I can tell you all day I worked around LOTS of stock stuff that was very very broken. (this year alone I did 4 motors in 6.2L Escalades that were bone stock)

All comes down to the shop doing it.... no matter what the mod.

JoesC5

yet some think you can just throw a blower on an otherwise stock engine, making an additional 200 horsepower, and it won't break.

C7pimp

Because you can.

My current daily driver puts out 215whp (480whp vs 265whp stock) over stock on a completely stock bottom end, stock headers, and it has not had an issue with over 1000 hard pulls on it, counting street and strip.

There will be the odd man out that breaks, but for the vast majority of cars, it's going to be long term reliable if kept in that range of reasonable output, not flirting with danger.

A car is only submitted to extra stress under WOT with a supercharger anyways. You theoretically could tune a car to 3000whp, and never break the motor if you keep your foot out of it. That's a ridiculous exaggeration, but it's true.

Blackdevil77

That's interesting. There is some risk with anything you do, but I was sure that a blower was much more "simple" than heads and cam.

I guess the safest way to go is to not modify the car at all and keep stock. It's kind of like abstinence. Safe, but no fun

That's what I've come to learn. Cracking into the motor is much more complicated. I don't want to crack into the motor. I'll stay completely stock before I do that again.

I had my hopes lol

Theta

That's essentially what you can do safely with this platform, though it's more like 180hp.

descartesfool

Maybe that is good advice for aftermarket boosted cars that make more power than they should (not over engineered, but rather under-engineered), but not true for well designed boosted setups. I have been driving the **** out of my turbocharged GT-R on road racing tracks for 5 years now on nothing more than 93 octane and engine runs just as good as new, and I'm talking thousands of track miles at top end lap times. Never, ever needed to put in 100 octane or octane boosters or anything else in the tank other than 93 from whatever local fuelling stop is within a couple of miles of the track.

Theta

That's kind of like saying methanol setups are just poorly designed and taken too far.

Do you feel that is also the case?

Blackdevil77

And your GTR is stock running factory boost, or is it upgraded somehow?

descartesfool

Stock, running factory boost, so properly engineered.