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Discussion Starter · #1 ·
Well, I've now gone about 10 years with my GM Goodwrench crate engine. It's done hundreds of drag strip passes with a 125 hp plate nitrous system, road racing events and many thousands of miles driving around, with no issues to speak of. Oil looks clean when I change it annually and doesn't burn anything.

About 3 years ago I added an Edelbrock E-Force Supercharger to the mix, and pulled the nitrous jets down to 50 hp equivalent. I've done a little racing here and there, but mostly street duty at this point in the cars (and my) life. The baby blower kit is rated for 5-6 psi, but I basically only see about 2.5 psi at WOT, unless it's seeing a ton of load (like straight up a hill in high gear), where it sneaks up towards 3.5-4 psi.

I'm planning to purchase a pulley from the Blower Shop to add a little boost, and the question is..... how far would you push it? I'd rather not kill the engine (it's been good to me), but I am at the point in my life financially that it wouldn't be devastating if I need a new long block.

The blower has a 3.75" pulley, and there's pulley's available all the way down to 2.75". My understanding is that each quarter inch change in pulley diameter is worth about 2 pounds of boost.

Would you try the 3.5" pulley (4.5 psi), 3.25" pulley (6.5 psi) or set it to kill with the 3" pulley (8.5 psi)? Keep in mind, I'll be spraying the little nitrous kit at times and this is a cast bottom end engine with about 8.2:1 compression. The rest of the drivetrain and chassis is set up to handle a lot of power, as needed.

Kev
 

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For the cost of a pulley, I would begin with the 3.5 inch. 2 additional pounds of boost should make a noticeable difference. If it isn't enough, you could always drop it down another 1/4 inch. Since your engine has a few miles on it and has been good to you, with proper care, you should be able to expect another "few" miles of fun from it. Good luck. and keep us posted.
 

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@novaboy009 found this old post in a 'vette forum I added a link below to the site:

"My recent change from a 3.5" to 3.25" pulley yielded right at a 1.5 psi increase. As for longevity...who knows. The C6 Edelbrock kit has only been on the market for something less than a year. It's going to take a long time to determine just how long it will last."


Hope this helps... Dealing with my current setup on my 2002 Lightning too... I don't want to grenade my motor... but a couple more lbs of boost would be nice. Sitting at 10lbs at the moment

~Andy
 

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Discussion Starter · #4 ·
I found in a few other places that it seems like the 1/4" change was closer to 1.5 PSI change. I think I'm going to try the 3.25" pulley and just be conservative with the timing. I've got a boost referenced AED custom blower carb and good fuel supply, so I'm confident on the feed side.
 

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@novaboy009 and if you feel lucky (and have it available to you), you can mix 1 gallon of E85 to 10 gallons of 91/93 octane gasoline and that should give you a good jump on the detonation issues to boot. Should give you some chamber and blower cooling too. I use it in my truck periodically and can squeeze a few more degrees of total timing out for a bit more pull. Works like a champ! Sometimes I go as far as 2 gallons per 10. Best to stay conservative on the pulley ratios too. You can always go bigger/smaller but once you detonate, it's too late and head gaskets aren't the strongest...
 

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Discussion Starter · #6 ·
Any issues with the E85 rotting lines or causing any other issues with that limited mix ratio? Do I need to do anything with the jetting? Or just leave it all alone?

Kev
 

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Any issues with the E85 rotting lines or causing any other issues with that limited mix ratio? Do I need to do anything with the jetting? Or just leave it all alone?

Kev
None so far, and I've been using this mix for many years, just not in Edelbrock carbs :) They no likey!! NOTE: Make sure your boost-referenced carb is E85 capable... although a mix won't hurt it at that level as most gasoline now has some ethanol mix of some % but the higher you go on the %, the more it causes issues unless your fuel system is capable of supporting it. I use PTFE lines on all my big stuff so it's impervious to the alky. Aluminum is not very compatible with the alcohols...
 

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Discussion Starter · #8 ·
I just sent an email to my carb builder to ask his thoughts on jetting and E85 use with the extra 3 psi. We'll see!
 
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