LS-7 conversion, do I need a bigger fuel pump?
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,152
Likes: 243
From: Northern VA
LS-7 conversion, do I need a bigger fuel pump?
Well, the car's on the dyno but shop is saying the motor is running lean above 5500 rpm. They don't think there's enough fuel. The pump is stock C5Z pump. Should it be enough? Stock LS-7 injectors but heads are ported a good bit.
Thoughts??
Thoughts??
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,152
Likes: 243
From: Northern VA
Maybe my stock pump is going... Apparently they switched fuel pump types mid run on the Z and depending on my VIN the pump is different. Early 03 and before is one style, later 03 to 04 it is the C6 style.
Apparently it just runs out of fuel after 5800 rpm. Duty cycle of stock LS-7 injectors have plenty of room at that point.
Apparently it just runs out of fuel after 5800 rpm. Duty cycle of stock LS-7 injectors have plenty of room at that point.
Acct Suspended APR 2026 by request
Joined: Dec 2010
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2020 Corvette of the Year Finalist (performance mods)
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you can easily see what type of system you have by looking behind the driver side rear wheel, if your sending unit is on the side of the tank you have the early style system... regardless I would recommend upgrading to a bigger pump, having more than enough available fuel is never a bad thing
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,152
Likes: 243
From: Northern VA
Lingenfelter's site has the VIN cutoff number for the new style pumps and luckily, It looks like have the old style. I've ordered the upgrade Walbro pump with Racetronix wire kit.
Now it sits some more waiting... grrrr
Now it sits some more waiting... grrrr
