Thread: Lt4 blower swap
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Old 01-18-2020, 10:54 AM   #29
Eldi Z

 
Drives: 17' 1SS 1LE GBA-Black
Join Date: Mar 2017
Location: TLV
Posts: 810
Quote:
Originally Posted by KingLT1 View Post
The LT1 indeed makes more power then a LT4 at the same PSI of boost. As you mentioned, The LT1 has a lot more compression which contributes to the increase. Honestly the LT4 supercharger works better on the LT1 because it doesn't need spun as hard to make power which equals lower blower temps. LT1's tend to dyno around 600whp on 9 psi and not 550whp like the LT4 on 93. The down side is the LT1 runs into a octane wall on pump gas around 10psi. So you need to supplement with Ethanol blend or Meth. LT4 can potentially make a lot more power on 93 octane with it's lower compression.

It's a good swap if you don't plan to go very far. I personally would run a larger 7psi pulley and run a blend of ethanol(E60) with LT4 fuel system. It will soften the hit since the little 1.7 makes a boat load of torque down low and still make the same if not a little more power up top as the 9 psi pulley on 93.
Good points.
For instance, my personal goal is no more than 570-580 RWHP tops. I do not plan on drag racing - just to increase my daily "fun factor" a little.

I guess that for such power goal the sweet spot for a clean pump 93 (no E and no Meth additions), would be 8 PSI of boost on moderate and safe timing advance?
From most of the information posted, so far the weakest link is the tight ring gap on the LT1 pistons, which calls for extra care when boosting.
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