TurboS13Hatch

iTrader: (5)

I started a thread in the "General Section", but was told to post it here.. thought you guys might want to contribute, read up..

http://forums.maxima.org/showthread.php?t=441424

I wish someone would have just moved it.. I didn't know where to put it..

Travis

Wish-it-was-AWD

Just a quick question TurboS13. Have you considered the additional mass of the larger pistons in your calculations about 8k-9k rpm. Granted the R/S ratio is the same but the additional mass of a larger diameter piston may be troublesome. Yes, the VQ is naturally a more balanced engine than any inline-4, however, I am just curious as to how you think bigger slugs are going to effect your high RPM capabilities. More mass in the piston, longer stroke and smaller (by 10mm) rod bearing journal may make for the potential for crankwalk. Just a concern. With that I will wish you the best of luck. I hope to see this work...I'd love to see it in an old 510 with a T66, tubbed with some slicks, or a Max. Anyway, if you are going to be building this, I would personally reccomend chamfering the oil journals on the crank and knife-edging it. Will help reduce windage drag and rotational mass as well as ensuring (hopefully) you stay well lubed in high-g loads in your sump, without a doubt a possibility with the amount of low-end grunt you will see in this motor. Get back to me and let me know what you think of the piston mass versus speed worries I mentioned. I'd be interested to see how you may overcome them. Good luck...To busted knuckles and Bourbon.

95turbo gxe

iTrader: (25)

hows this project coming?

TurboS13Hatch

iTrader: (5)

I don't see rotating mass as an issue... There's tricks to lighten up pistons/rods if need-be.. But, hell, I've seen SR20's rev to 9K.. and they have SUPER heavy rods/pistons from the factory. If anything, I think a larger bore diameter will provide helpful in absorbing the load better.. (more surface area to displace the load over)

The project is progressing.. just doing all the leg-work right now.. Patience..

Hoooper

youre putting a turbo on a stroker? strokers put more stress on the engine as it is...putting a turbo on could be a disaster.

DA-MAX

iTrader: (10)

um, okay...how so??

when you build up a stroker kit, you will usually use forged and upgraded components so it will more than be able to take the stress if bult right. I think many people have the misconcpetion that "stroker" means you have to have higher compression when it doesn't. you can easily have a stroker kit with lower compression to be applied to forced induction.

TurboS13Hatch

iTrader: (5)

*sigh*.... lol..

Travis

DA-MAX

iTrader: (10)

LOL, I think thats about the 800th time I've seen someone post that type of statement in one of your "storker threads" alone

Hoooper

it has nothing to do with the compression...although boosting a high compression would be bad. When you have a longer stroke, you get more torque because the piston has more room to speed up, which means its going faster at the top of the cycle than a normal engine. When it tries to slow down, the increased wieght and force of the piston puts a bunch more stress on the crank and main caps than a normal engine, thats why strokers usually have a lower redline. more stress=more likely to break, more boost=more likely to break. more likely to break+more likely to break=likely to break...

DA-MAX

iTrader: (10)

again, if its built right than again whats wrong with turboing it?

mtcookson

iTrader: (2)

Usually the higher you rev an engine, the more likely it is to break. That's what having a lower redline with boost makes a pretty good engine. Tons of torque... lots of fun.

Stephen Max

iTrader: (59)

There's a much simpler explanation for the additional torque that a stroker gives.

Torque is just the downward force exerted by the connecting rod on the crankshaft, times the moment arm. The moment arm is the horizontal distance from the center of the connecting rod big end to the crankshaft axis of rotation. When the crank angle is 90 deg, the moment arm is equal to the crank throw. You increase stroke by increasing the crank throw, and that results in more torque.

TurboS13Hatch

iTrader: (5)

Tell that to the AMS guys.. who are making 840awhp with thier 2.3 liter stroker.. lol..

Seriously guys.. please pick up a book... do some reading.. get your hands dirty.. LEARN something.. before you try to correct people who obviously know WAY more than you do.

Travis

Hoooper

yes you know way more than i do...i know exactly what im talking about. i said if you built it it might work, but if its just somewhat day to day components its jacked. are you trying to argue that a stroker puts = or less stress on than a shorter stroke engine?

Nealoc187

iTrader: (23)

By your logic no one should mod at all, since even an intake puts more stress on the engine... heck we should all make our cars less powerful as to reduce the amount of torque produced.

Yes there is more stress being produced but the components which that stress is acting upon will also be of much higher quality and strength.

Hoooper

i never said it WOULD break, i said its more likely to break. i know if its built right it wont break...look at the dragsters, theyre runnin on 45 PSI and they dont break every run.

TurboS13Hatch

iTrader: (5)

Of course a stroker puts more stress on the internals.. Is it enough to worry about? No.. Look at Nissan's QR25DE.. 1.43:1 R/S ratio.. it has TINY rods.. People make 300whp/280wtq on stock internals all day long. There's 1 case of a rod failure that I know of.. out of about 60 people running turbo kits. And, that failure happened at 240whp.. It was a freak thing.. The only thing that a stroker does.. is put more stress on the piston's skirt.. and a little more stress on the rod.. because of the angle that it gets to. It's not THAT big of a deal.. and certainly.. has nothing to do with turbocharging the engine.


Travis

Hoooper

what it has to do with turbo is that turbo puts more stress on, on top of the increased stress from a stroker. tiny rods, btw, are good. the rods on a nascar engine are as far around as a sharpie. tiny works because its lighter and therefore has less rotational weight...less stress.

TurboS13Hatch

iTrader: (5)

Just out of curiosity... how many strokers have you built/turbocharged? I've got at least a dozen under my belt.. The biggest one making 630whp.

Any engine has to be built to withstand the output that you're shooting for.. The stroke/rod length really isn't THAT big of a factor in terms of stress on a part. It just doesn't come up in discussions when you're talking about building a engine.

And yes, tiny works great when you're trying to build a very efficient, N/A motor.. and not going for big power. But, it's place in your argument is moot... The only thing that the rotating assembly must do, is survive whatever power you're looking to make. Nascar rods are NOT small..

Travis

Hoooper

go check out a nascar rod, my friend has been around the motors and ive seen em, theyre nice and skinny. and yes if you build any engine enough it will work. but do you want to drive an engine with a 300 pound rotating assembly around on the street?

TurboS13Hatch

iTrader: (5)

So, how many strokers have personally built and turbocharged? Seriously.. if I didn't know what I was doing.. I wouldn't have posted the idea here. If you have some hard data/facts to back up what you're saying.. then, please post them. I know what I'm doing.. I've been doing this for a long time. Just because no one here has done anything like this with the Maxima.. it doesn't mean that it can't be done.

Travis

Hoooper

i never said it couldnt be done. all i was saying is that if you dont build it right it may have issues with too much boost. and yes, stock engines can handle a fair amount of boost, but if you plan to put more than that on a stroker, it needs to be built well. i believe that youve done it, i have no doubts...with enough work anything can be done

mtcookson

iTrader: (2)

just like any other engine ever made.

Hoooper

yes, except with a lower boost threshold.

Stephen Max

iTrader: (59)

Okay, you've made your point. Let's move on.

JClaw

iTrader: (17)

I'd be very interested in doing this N/A. If the 3.5L can do 300whp N/A, a 4.0L with 12-12.5:1 comp, ITB's and big cams could put down real good numbers N/A.

95turbo gxe

iTrader: (25)

Yes that would be agood idea too I wonder what the cost would be as to just boosting one though?

JClaw

iTrader: (17)

Well if Travis is right:

Best part is I could keep my stock VQ35 block/rods. No need to send your block anywhere. Maybe I could simply ask Travis to buy the VQ40 crank, prep it, buy that off from him, then get custom pistons for the 12-12.5:1 compression, the new 600$ cams and then get it assembled in the stock VQ35 block.

In fact I am curious as to what the compression ratio would end up being with the prepped VQ40 crank but still using the stock VQ35 pistons/block & heads. Shouldn't it increase it (reasonably) which would be perfect for N/A? That would decrease the cost even more.

stephenlc

iTrader: (1)

They are also titanium rods. So they don't need to be super thick.