Mild build, injectors?
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Drifting
Joined: Aug 2009
Posts: 1,971
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Mild build, injectors?
355 LT1 with LE ported stock heads w/larger valves, ported intake and a mild cam, short tubes, electric WP, list goes on. Expecting a solid ~400hp
Car has its original 24lb injectors and ran well with this same head/cam setup when it was a 350. I was happy with my AFRs on the wideband through rev limit set at 6100 and had taped a mechanical fuel pressure gauge to dash to confirm I wasn’t losing psi in the top end. So it seemed the stock injectors and still original fuel pump were up to it but I don’t recall what the injector duty cycle was.
The 355 is getting the same heads, freshened up, and same cam. It’s going to have a little more compression and way better forged rods, hyper pistons and while I expect a refreshed motor to run stronger I don’t think it’s going to make much more power than the prior setup, what’s 5 cubes worth anyway. I think the stock injectors will still workout ok, but not really sure. With the rebuild I’m debating sending the injectors off to FIC for service and questioning if that is the right call or if I should be looking at bigger set or new/different injectors. What have you other mild 355s done?
Car has its original 24lb injectors and ran well with this same head/cam setup when it was a 350. I was happy with my AFRs on the wideband through rev limit set at 6100 and had taped a mechanical fuel pressure gauge to dash to confirm I wasn’t losing psi in the top end. So it seemed the stock injectors and still original fuel pump were up to it but I don’t recall what the injector duty cycle was.
The 355 is getting the same heads, freshened up, and same cam. It’s going to have a little more compression and way better forged rods, hyper pistons and while I expect a refreshed motor to run stronger I don’t think it’s going to make much more power than the prior setup, what’s 5 cubes worth anyway. I think the stock injectors will still workout ok, but not really sure. With the rebuild I’m debating sending the injectors off to FIC for service and questioning if that is the right call or if I should be looking at bigger set or new/different injectors. What have you other mild 355s done?
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Joined: Jan 2023
Posts: 50
Likes: 7
From: Denver
It’d be worth running down what your duty cycle is. I think 85% is the max recommendation for anywhere in your map generally.
A couple quick calculators like the one below guesstimated that you’ll be pushing the limit with the 24s if you’re around 400hp at the crank. I think you can probably get away with them but you’ll be pushing the cycle time which doesn’t necessarily leave a lot of room for corrections the computer might want to put down. I imagine it also shortens injector life a little bit.
https://deatschwerks.com/pages/fuel-injector-calculator
A couple quick calculators like the one below guesstimated that you’ll be pushing the limit with the 24s if you’re around 400hp at the crank. I think you can probably get away with them but you’ll be pushing the cycle time which doesn’t necessarily leave a lot of room for corrections the computer might want to put down. I imagine it also shortens injector life a little bit.
https://deatschwerks.com/pages/fuel-injector-calculator
