How much modification can you do before needing to consider building bottom end

I am considering modification but am concerned about how much power can you get before needing to beef up the crank and pistons.
I'd like to get some more power but done really want to have to do a complete overhaul at this time.

Any recommendations for moderate tuning?
I'm thinking the obvious ones such as intake, exhaust, down pipe possibly, injector tips and a chip. considering cam but that that might be to big of a jump at this time.

Cheers
John

Your main problem will be bending rods. Anything over 200hp has the capability to bend a rod. Doesn’t mean you will. A very good friend has the gtb22260 turbo set up plus over sized valves and stage 3 colt cam and still have the stock bottom end. I would have to say it will bend or blow a rod eventually but has not yet. He has to be making 210-220hp and torque I’m sure is double.

Hijack alert....

Okay, anyone know what the stock bottom end of a 2.0 CR is good for? 09-14 CJAA/CBEA?

Looking at big turbos. Will be doing all the fixings, but wasn't planning on a bottom end build.

do the rods bend from the HP or high boost pressure?

in theory if someone had all the other things done on a stock bottom end making say 230hp with only 30psi vs 40+psi wouldn't that last longer?
i am talking about head work, intake, turbo, IC system, injectors, tuning ans so on.

I think they coincide with one another. 30psi on a vnt15 is not the same as 30psi with a gtb turbo. HP was always the guideline that I’ve seen and went by. Most likely if you are making 200+hp there is a decently size turbo being used. My golf engine I recently built has the capability of 300hp safe running 35-40psi with a gtb2260. There is room for more power I would say since i built the bottom end and bored it to a 2.0. I think the main problem for more power is fueling.

that's kind of what i was thinking but had to ask.


blowing a stock 1.9 up is kinda like "you want to get shot in the head or chest"? either way your dead so does it matter how you got there lol

With the alh there is a chance of blowing a rod but the most likely thing will be a bent one. I’ve heard a lot of people didn’t even know they bent one until a compression check was done. But hey bending a rod and lowering compression you can add more boost haha.

sardo_67 said:

do the rods bend from the HP or high boost pressure?
.

Click to expand...

torque is cylinder pressure, which breaks parts
one easy way to get more power through a stock engine is to ditch all the tiny bolt on turbos

with a tiny one you center your powerband too low in the rev range, by the time you're spinning 3k+ you're making a lot more HP than you actually see out of the engine lost to the restrictive turbine.
Strap on something like an s200, he2xx, a larger td04 or td05, and it'll breathe a lot easier so you aren't making an extra 50hp or more just pushing exhaust through the turbine.

this question is like asking "how high can I jump off a building before I break my leg?"

so open ended

So many variables... how long do you want it to last, how do you drive, intended application, (rally, drag, street, endurance racing, MPG, etc...)

KERMA said:

this question is like asking "how high can I jump off a building before I break my leg?"

so open ended

So many variables... how long do you want it to last, how do you drive, intended application, (rally, drag, street, endurance racing, MPG, etc...)

Click to expand...

lol best analogy I've read in a while.

I agree, far too vague of a question with no context to garner a good answer.

Generally, the ALH is pretty tough, but you have to remember that a 150hp ALH is not like a 150hp AWP. If you want to be able to drive the car comfortably around town, in traffic, etc. I think you'll be fine with anything the stock bottom end can handle.

I think a lot of people come in talking big, but once the real world sets in, they back down.

If you really want to make a lot of power, safely, you need to lower the CR and up the boost. No easy way to lower CR without tearing into the bottom end. Peak cylinder pressure is what bends rods. But you go too low on the CR, and it'll be a pain to start, be smokey and noisy after a cold start, and may not run worth a darn until it gets some heat in it.

I've driven some heavily modified diesels that were so horribly undriveable under "normal" conditions, that the insane amount of peak power they could put out quickly lost its impressiveness.

[486] & Oilhammer I was wondering when you 2 would come in and put down some good input. Hopefully the OP reads it all.