YSi Guys, what fuel do you run?

[mystical]

Hi folks, I've got a '98 Cobra with a built 305" big bore and a YSi. Currently running 110 race gas. I spoke to my tuner regarding getting it tuned to run on pump. He said with the stock compression of my motor, the YSi would be too big of a blower to run on pump. It would have to be pullied down way too low out of it's efficiency range and will prematurely kill the blower according to him. Basically, he's telling me to stick with the 110 which is not what I wanted to hear. Fwiw, the car has meth injection as well.

Would like to know what fuel YSi folks are running??? Thanks.

 

[2001sleeper]

I run 17lbs on 93 pump gas.
This summer I will shoot for 22lbs and see where that puts me. If the pump gas is not enough I will switch to E85.

 

[Roll Race Rob]

ya typically you dont want to push it ,much more than 15-17psi with pump gas...

 

[AntiHeightPunk]

im getting tuned for 93? Than when E85 is easier to come by im going to grab some E85

 

[crashtke]

Get ready to do a serious upgrade to the fuel system for E85. But to answer the original question, we had an 03 Cobra running on 93 with a Ysi Renegade class. Over 20 psi without problems.

 

[AntiHeightPunk]

i have a full return setup with 80 LBers

 

[BM1]

You really don't need to worry about using pump gas since you're using meth. If it's setup right and you're using a proper mix, it's essentially race fuel octane levels.

 

[crashtke]

Yes and no....if you inject a LOT of it, then maybe. But E85 and Race gas still will win the day. The main advantage meth gives in cooling the intake charge adding a tad to the octane. But if it quits on you...say goodbye to the engine.

 

[BM1]

Actually, it depends on the type of alcohol you use, mix strength, and how much you spray.

A 50/50 methanol/water blend with a tank of 93 pump gas will be approximately 105-110 octane when calibrated properly. You could go higher with a more aggressive mix but it's not recommended for a street setup.

Also, a failed injection system does not equate to a blown motor if the system is set up correctly. Setting it up correctly means making sure the IAT is positioned after the nozzle so that it can accurately measure charge temperatures when methanol is used. A good tuner will then provision your tune to pull all the timing and dump a ton of fuel if intake temperatures go above a certain threshold. You also should use an in-car wideband when using a setup like this so that you can monitor what is going on. Some of the newer kits such as AEM also have a built-in monitoring system that will alert you via LED light if there is a pump or system failure.

I'm not saying methanol/pump is better than race fuel, but it can be a good substitute in certain applications (ie street cars). It's also a good safety net due to the fact that the quality of pump gas usually varies quite a bit.

This is all way off topic though. There's some good information here if you're interested.

http://www.alternativeauto.com/waterbox/wb_archives/meth_injection.html

 

[2001sleeper]

A 50/50 methanol/water blend with a tank of 93 pump gas will be approximately 105-110 octane when calibrated properly.

would you care to elaborate on this or are you just passing off random information you heard elsewhere.

 

[BM1]

would you care to elaborate on this or are you just passing off random information you heard elsewhere.

I got that information from Bob Kurgan. He set up and tuned both of my meth injected cars. He said the meth can add UP TO 20 points.

Both of my cars were tuned for 100 octane on the pump/meth combo just to play it safe.

OP: Sorry for the hijack.

 

[2001sleeper]

i'm sure bob knows his tuning, but i'm not buying the stated octane increase. There are other chemical effects taking place inside that cylinder since you are flowing methanol, water, atmosphere, and fuel into that cylinder. It all may add up to running more timing and such, but I seriously doubt that the octane increase is that considerable since methanol by itself is only ~120.

to the OP, get a good tuner, some quality pump gas and see where your blower will take you. I think 18-20 on pump gas is obtainable wtih the proper setup.

 

[BM1]

That's fine, but I wouldn't count it out completely. It is a proven combo.

 

[mystical]

Good discussion guys, that's what I like to see:beer:

Alternative actually built and tuned the car. Lidio claims that the meth doesn't actually increase the octane much if at all but rather helps with cooling. I wonder why the article on his site says it's a "huge octane booster":shrug:

Anyhow, he likes to be on the safe side and recommends the 110 to most blown guys running decent boost. The problem with that is I don't have access to the stuff where I live and even if I did it's a street car and I don't want to be paying the huge premium for it.

 

[BM1]

You'll be fine on the meth/pump combo.

 

[mystical]

Get ready to do a serious upgrade to the fuel system for E85. But to answer the original question, we had an 03 Cobra running on 93 with a Ysi Renegade class. Over 20 psi without problems.

Stock 8.5:1 compression?

 

[mystical]

You'll be fine on the meth/pump combo.

I hope so, time will tell.

 

[04cobradude]

i just recently tuned a Mark VIII with a built longblock, non intercooled YSi, built tranny, low compression, 93octane, and dual nozzle meth... we ran 18psi and made 680rwhp through an unlocked 4r70w trans... charge temps went from 220deg to 120deg with the dual nozzle meth.

 

[04cobradude]

Get ready to do a serious upgrade to the fuel system for E85. But to answer the original question, we had an 03 Cobra running on 93 with a Ysi Renegade class. Over 20 psi without problems.

what is a "Ysi renegade class"