S54 Stroker build

[Jhinz03]

If you destroked you’d just run a shorter final drive to make up the difference. The engine will just be a bunch busier in that it will always spinning faster at a given road speed. Personally I’d rather have the stroke for a bit more effortless / accessible performance.

the power is always in the top end of the engine the bottom end just determined the rpm where it happens (scales peak hp rpm up or down)

it’s amazing how many think stroking an engine makes more peak power inherently as it’s just completely wrong to assume that. It’s not to say you won’t get gains but it comes down to what’s limiting power in the first place

If I end up stroking it, it would be to gain some lower end torque. I'm less concerned with getting a big number at 8300 than general driveabilty and all around fun experience. It's going to be a daily more than anything. I have a short, relatively traffic-free commute, but the wife and I also like to go for a drive sometimes at night (which is why I'm actually looking for the drop top). If I just wanted a huge HP number, I'd slap a custom turbo kit on it and call it a day. The fun factor is also part of the reason for the velocity stacks over a CAI. I just like the sound they make and the feel of the throttle response. I think I may just grab some lightweight Carillo rods since they support 400whp and I dont plan on going higher than that and some 12.5:1 pistons. Also debating 14mm lift on the cams and having the pistons recessed a little.

Am I wrong in thinking using lighter internals would reduce drivetrain loss to the whp?

[digger]

If I end up stroking it, it would be to gain some lower end torque. I'm less concerned with getting a big number at 8300 than general driveabilty and all around fun experience. It's going to be a daily more than anything. I have a short, relatively traffic-free commute, but the wife and I also like to go for a drive sometimes at night (which is why I'm actually looking for the drop top). If I just wanted a huge HP number, I'd slap a custom turbo kit on it and call it a day. The fun factor is also part of the reason for the velocity stacks over a CAI. I just like the sound they make and the feel of the throttle response. I think I may just grab some lightweight Carillo rods since they support 400whp and I dont plan on going higher than that and some 12.5:1 pistons. Also debating 14mm lift on the cams and having the pistons recessed a little.

Am I wrong in thinking using lighter internals would reduce drivetrain loss to the whp?

i wouldn't destroke it then as youd only do that to improve the bottom end reliability/durability at higher rpm.
Lighter rods wont do much of anything for dyno performance. if you want a lighter rotating weight then rods are not the low hanging fruit.
Its easy to to spec the pistons to suit cams in any case. i'd get a Mahle MS 4032 type alloy.

[Jhinz03]

What would be the low hanging fruit for reducing rotating weight? I'm likely swapping the rods anyways if I'm already opening the engine, so that seemed a logical choice. I will eventually start trying to lighten the car as much as reasonable. I wouldn't open the engine JUST to swap in lightweight rods, but if I'm in there, I figured why not. Eventually looking at things like a CF driveshaft, I have budgeted for forged wheels that'll drop 55lbs and a lightweight battery whenever the stock battery needs replacement.

[mrgizmo04]

3.5L Stroker

https://youtu.be/A0GiUoGkf0k

Sent from my SM-G950U using Tapatalk

[digger]

What would be the low hanging fruit for reducing rotating weight? I'm likely swapping the rods anyways if I'm already opening the engine, so that seemed a logical choice. I will eventually start trying to lighten the car as much as reasonable. I wouldn't open the engine JUST to swap in lightweight rods, but if I'm in there, I figured why not. Eventually looking at things like a CF driveshaft, I have budgeted for forged wheels that'll drop 55lbs and a lightweight battery whenever the stock battery needs replacement.

Flywheel, clutch and pressure plate are where the rotational inertia is in the engine

youd be nuts to choose 1700 rods to gain nothing material when you can do Actual performance mods.

[Jhinz03]

Flywheel, clutch and pressure plate are where the rotational inertia is in the engine

youd be nuts to choose 1700 rods to gain nothing material when you can do Actual performance mods.

Oh I wasn't changing the rods to try to gain performance. I was changing the rods as part of building out the engine due to it being nearly 2 decades old and likely having over 150k miles on it. I was going to go to a forged H-beam rod anyways, and these were the same price as the standard rod. I figured a lighter rod might reduce parasitic loss and maybe help it rev a little quicker. I'm hesitant to lighten the flywheel since I'm worried about making shifting in Miami rush hour a pain. Clutch is on the build list.

[8 Coupe]

Flywheel, clutch and pressure plate are where the rotational inertia is in the engine.

My rebuilt engine is now in the car & I have a couple of pics showing the low rotational mass of the JB Racing Ultra Light Flywheel & Clutch kit - very well designed & manufactured kit but only suitable for use on the track.