TGPForums.com

MODIFICATIONS => Performance => Topic started by: TGed on August 05, 2009, 04:43:02 PM

Title: Knowing the Limits
Post by: TGed on August 05, 2009, 04:43:02 PM
Most of us know their are limits to injectors and how much they flow, but what if you used different octane?  
How much more could you gain with proper tune-ability going from 89 octane to 104 using same size injectors?  
Lets say you have 28# injectors, what or how much does octane change it's supporting factors?  

I was thinking about doing a build using all junkyard parts, and I already have a shelf of 28# that I might use depending the feedback.  



-------------------

I also have another different thread asking about something different but sort of the same concept...  Two separate cars though.  :p  
See it here:
http://www.tgpforums.com/index.php/topic,5487.new.html#new
Title: Re: Knowing the Limits
Post by: meltboy11 on August 06, 2009, 12:59:02 PM
I don't know the answer for you, but I was also wondering how my car would react to 104 octane, we got 1 pump in Utica that carries it and I was wanting to try it out with my 302s...

I had put a few gallons of 104 in my old 91 after my rebuild years ago, and leme say did it wake it up, and made the exhaust smell damn nice too. I assume the TGP could handle it fine, but I was a little weary of putting it in.
Title: Re: Knowing the Limits
Post by: TGed on August 06, 2009, 01:10:16 PM
I run big ole injectors and 110 in the other Gen2 motor in the other "car" .  I kind of have to though.  Only downside is, each year I have to change o2 sensors.  So pretty much $100.00 every spring is a gaurantee prior to running.  DO'H!

This motor, I don't want to buy injectors unless I REALLY have too, and running 104 is not that hard to get and slightly cheaper than 110 by about a 1.50/gallon.


No special precautions have been taken in to account for the 110 LL octane, engine been running off it for 3 years minimum.
Title: Re: Knowing the Limits
Post by: killinprixs on August 06, 2009, 01:48:36 PM
Without any specs on the car id say as long as your not already getting detonation, and again i dont know how much boost you are trying to run or any specs on your car but a good tune and 93 goes a long way if you are really good at tuning.  The higher octane i suppose could let you run more timing or serve as a saftey for track use or hotter conditions.  I wish i could help you out but i am by no means claiming to be a pro tuner  :laugh:
Title: Re: Knowing the Limits
Post by: TGed on August 06, 2009, 02:35:20 PM
I know that tuning and 93 or just plain tuning goes a long way, I just want to know the limitation to #28 while using 104 octane.  Like does anyone know their max power limits (regarding them in a 3.1) ?
Title: Re: Knowing the Limits
Post by: flybynite on August 07, 2009, 09:52:38 AM
Quote from: TGed on August 05, 2009, 04:43:02 PM
Most of us know their are limits to injectors and how much they flow, but what if you used different octane?  
How much more could you gain with proper tune-ability going from 89 octane to 104 using same size injectors?  
The higher octane fuel will help/eliminate detonation but it does not allow your injectors to flow more fuel. With the higher octane you can increase timing and that will increase HP #s.
The 28lb injectors will hold around 325 WHP. If you add in the higher octane fuel and increase timing, HP #s will increase as well...   :icon_twisted:
Title: Re: Knowing the Limits
Post by: TGed on August 07, 2009, 10:21:01 AM
Quote from: flybynite on August 07, 2009, 09:52:38 AM
The higher octane fuel will help/eliminate detonation but it does not allow your injectors to flow more fuel. With the higher octane you can increase timing and that will increase HP #s.
The 28lb injectors will hold around 325 WHP. If you add in the higher octane fuel and increase timing, HP #s will increase as well...   :icon_twisted:

Awesome info, thanks!
Title: Re: Knowing the Limits
Post by: mfewtrail on August 07, 2009, 10:27:57 AM
Quote from: meltboy11 on August 06, 2009, 12:59:02 PM
I don't know the answer for you, but I was also wondering how my car would react to 104 octane, we got 1 pump in Utica that carries it and I was wanting to try it out with my 302s...

If it's not needed, it's not going to help you any and probably hurt performance somewhat. With a stock or topgun chip, 93 is plenty.

For what it's worth, dbtk2 posted about running 87 octane in his car with no knock a few years ago.
Title: Re: Knowing the Limits
Post by: GutlessSupreme on August 07, 2009, 05:51:11 PM
wasn't dbtk2 living somewhere highish altitude though? Not that you couldn't get away with it, especially with the right tune, but it does make a difference...
Title: Re: Knowing the Limits
Post by: GPChief on August 07, 2009, 06:21:24 PM
Quote from: GutlessSupreme on August 07, 2009, 05:51:11 PM
wasn't dbtk2 living somewhere highish altitude though? Not that you couldn't get away with it, especially with the right tune, but it does make a difference...

He is a MI person. 

Here in Colorado I can run 14 psi all day long because of the altitude.  But my times at the track are always slower also.
Title: Re: Knowing the Limits
Post by: TGed on August 07, 2009, 07:27:07 PM
I'm going to try running 28#, 110 octane, AND alcohol injection (big maybe on this one) .  The injection kit all determines how hard it's going to be to put a junkyard kit together and for how much effort/$.  I should have a positive turn out on this, being that I do have resources to score some decent parts and a low cost deal. 

Going to see how far this junkyard gen2 will go on junkyard parts.  I shall call it, THE Savaged Beast.
Title: Re: Knowing the Limits
Post by: GPChief on August 07, 2009, 08:17:39 PM
Sounds good, let us know how you put your Alky kit together with the junkyard parts. :icon_cool:  I've had many ideas but never found the time to make anything.