What is or are the best mods for Bottom End performance?

Have the stock crank turned, polished, deburred and shot peened; get the Eagle 4340 forged rods & forged pistons from Wiesco,JE Arias and others;Clevite coated rod & main bearings;ARP head & main studs;2.3 oil pump & drive gear for the crank, remove balance shafts & modify block/oil passages; Miller Performance modified oil pan to clear the 2.3 oil pump; LGO 2.3 HO balancer that's about all I can think of of coarse get your block bored/plate honed, align bore & hone the mains, get rotating assembly balanced.


2000 Z24 5spd header & catback for now.

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Have the stock crank turned, polished, deburred and shot peened;

I wouldn't go this far. If the crank journels are deeply scratched then turn the crank, if they are not, I would use Emery cloth only. The problem is that you don't know if the crank had to be machined on the assembly line. Shotpeen ONLY if it is a cast crank. Many manufacures have returned to forging cranks. If it is forged your best bet would be to freeze the crank to strengthen it.

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get the Eagle 4340 forged rods & forged pistons from Wiesco

Why?? This would depend on application. If it was a turbocharged project I would use stock hats with forged rods. If it was an N/A project I would deck the head & block before I slamed rods and pistons in. You really need to calculate it according to the fuel you plan to use.

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2.3 oil pump & drive gear for the crank, remove balance shafts & modify block/oil passages; Miller Performance modified oil pan to clear the 2.3 oil pump; LGO 2.3 HO balancer that's about all I can think of of coarse get your block bored/plate honed

Why not remove the balance shaft altogether. Less rotation mass will give you more power, but a far more rougher ride. Block boring, should be used in ether repairing a block or increasing displacement. BUT you run into the issue of wall thickness and sleeving. Each has its own pros and cons. Measure according to your projects applications and budget.






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I'm gonna go out on a limb and say that he's not referring to the bottom end of the motor, but rather, how to get more low end power - more power off the line.

If that's the case, I don't think there's really anything you're going to find that's going to give the lower RPM range a big boost of power - it's a 4 cylinder engine, it makes power by revving higher than a larger displacement motor. The most successful builds are the ones that adhere to that concept - i.e. you don't plan to make all your power down low but rather focus your efforts on the upper RPM range. Think about it, in a racing situation, once you're off the line, when you shift near or at redline, your RPMs don't drop a great deal, so you're really only in those low RPMs for a couple seconds to start with and then after that you're up higher in the powerband.

If you still really want to try to get more power down low (and the results probably won't be all that fulfilling if you try) your best bet would be a smaller diameter exhaust (probably no bigger than 2.25"), a 4-2-1 header, and maybe a slight overbore with higher compression as higher compression tends to produce gains across the powerband. I believe if I remember the theories correctly you don't want a lightweight flywheel or anything like that as it will also tend to rob you of a bit of the low end torque. However you're still probably only going to pick up a couple HP at most down on the bottom end, and you probably also won't see nearly the gains overall that you would have because you're restricting your top end power to a degree.

If you're really after tire smoking, burnout contest winning power, go out and get a car with a V8.

Thank You MARCUS, that was what I was asking

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If you still really want to try to get more power down low (and the results probably won't be all that fulfilling if you try) your best bet would be a smaller diameter exhaust (probably no bigger than 2.25"), a 4-2-1 header, and maybe a slight overbore with higher compression as higher compression tends to produce gains across the powerband. I believe if I remember the theories correctly you don't want a lightweight flywheel or anything like that as it will also tend to rob you of a bit of the low end torque. However you're still probably only going to pick up a couple HP at most down on the bottom end, and you probably also won't see nearly the gains overall that you would have because you're restricting your top end power to a degree.

Point well made. But I have found that driving techique can help compinsate for some of a 4 cylinders performance issues. I use a lightweight flywheel in my Integra. I have to heal toe shift as I attack a corner. I also use a LS trans with a Type-R final drive. The combination of longer duration cams, higher compression and less rotating mass can help massively in low end torque.




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