Few questions about crank pulley and larger throttle body

[Zivman]

first off, I don't have a msp, have an '01 stratus coupe R/T and '04 nissan 350Z. Anyways, I have a friend of mine that does have a VERY lightly modded msp (like cooler plugs and some stickers). I just sent my throttle body off my Z in to proflow to be bored and inquired for him about this service for his msp. I did a little poking around the forums here and found little interest about this for the speeds.

I had this done on my stratus and thought it gave nice throttle response and would have thought that turbo'd cars would be all over larger throttlle bodies. Anything to increase airflow to the motor would seem like money well spent. Why the lack of interest in larger throttle bodies?

Also, I did some searches on unorthodox crank pulleys and yes, I am aware of the pros and cons, but my question is, does anyone know if the MSP engine is internally balanced with or without the flywheel and clutch attached? If they are balanced without the flywheel attached, the harmonic balancing should be a non issue, correct? Any lightened flywheel would have the same possible problems as a lightened crank pulley. Crank pulleys have been used on lots of cars for lots of years including the TT 300Z without issues. I would think that this would be great way to get a decent amount of power accross the enitre RPM range.

 

[Velocifero]

i dont know too much about how to answer your questions, as to the throttle body, i was looking at options to opening mine up some, there are a couple that you can buy that are already larger, i dont know about boring one out, sure its possible, just havent read about anyone doing it, but i am new to the msp community.

 

[boomergt]

Hey Zivman... Man your a bonehead....


Nice post. We were talking about these items yestarday and figured to ask for your guys input.

TIA

 

[Torco-MSP]

i would like to put a bigger throttle body on but no one makes one at a reasonalbe price with that much of a bigger bore.

 

[daedalus]

yea the AutoEXE one is 540.00!!!!

YIKES!

 

[blynzoo]

The TB flows well, and is big for the size of the motor...unlike the one on the chrysler 4's... There are a lot better places to look for power than the TB on the FS block.

 

[BlkZoomZoom]

Yeah just ream it out yourself.

Oh and a colder set of plugs on a stock motor is acutally hurting him.

 

[speed1016]

word!! He should stay with the stock plugs unless he boosting abit more,if Im not mistaken

 

[Zivman]

word!! He should stay with the stock plugs unless he boosting abit more,if Im not mistaken

I was just giving him (boomergt) shyt in regards to the plugs and stickers - he is running the Denso Iridiums, which I don't know if they are colder, but they are COOLER, in the LL COOL J sense of the word. They have to be because they are a mod, right?

All kidding aside, you all don't have much interest in a bored throttle body? How would you suggest you do it yourself when you need to replace the throttle plate as well? I know proflow usually charges less than $200 for the service. Is that too much?

Like I said, the throttle body I had done before increased throttle response and I would think that this is what guys driving turbo'd cars would want. Anything to get that engine reving quicker would be something worthwhile. I think proflow states a 11-13% increase in flow on the bored Z throttlebody. That increase in flow on the msp throttle body wouldn't translate into whp?

 

[BlkZoomZoom]

I had put a a larger plate in one of my tb. I had milled it out too far tobe safe
and it ended up not being, it cracked one day. I have since put in a mildly ported and fully polished tb. I have never noticed a difference, even from stock. However I am running some decent numbers.

 

[Velocifero]

why are cooler plugs not better? i got NGK copper plug for free but havent put them on yet, was going to wait til i got some better wires, i know these are one level cooler than stock, why is that bad? other people informed me cooler was better.

 

[BlkZoomZoom]

Colder plugs are a safe gaurd to detonation if you are upping cylinder pressure. If you are stock, stock is better.

 

[Velocifero]

if i drive at stock to 9 psi daily, usually stock, but turn up occasionally for track days to around 13, but then back to stock after that, what would you recommend? stock plugs or cooler?

 

[bill harvey]

I have bored out throttle body and i liked the better response that came with it.

 

[Zivman]

I have bored out throttle body and i liked the better response that came with it.

Do you know the specs on it? What they bored it to?

 

[bill harvey]

not sure corksport is where i got it i think it is a 62mm but i am not sure

Do you know the specs on it? What they bored it to?

 

[bored132]

60mm (from 55mm)

 

[Zivman]

60mm (from 55mm)

unless he bought the $540 replacement TB, I don't think that is right. They have a $255 rebore service which is what I think he had done, it would be more like 55mm to something like 57 or 58mm. I wanted to know so I could compare it to what proflow says.

Anyways, done tons of reading on crank pulleys and no matter what you read, there is all sorts of misleading and contradicting info.

It seems that those on this forum that are concerned about problems are concerned about the following two things:
1.) Oil pump failure
2.) premature bearing wear - crankwalk

I found that the MSP engine is internally balanced and as long as the pulleys you are putting on are balanced as well, they shouldn't cause any problems. In terms of the oil pump, I can't see how a crank pulley would be that detrimental. installing lightweight flywheels really get the motor reving quickly and this is what is supposed to cause the oil pump to fail. As a result, any lightened flywheel would pose more potential trouble to the oil pump than a crank pulley.

In terms of permature bearing wear, this is a non issue if you have a balanced crank pulley. Any reputable company, ie: unorthodox, sells only balanced pulleys.

There has been much debate on the 350z sights that I frequent in regards to pullies being harmful and has presented a case where a pully caused damage to a motor. On this sight there is a person that claimed a pully caused an oil pump to fail, but I somewhat addressed this earlier in my post.

We are seeing good gains with pullies on the Z:
Link to Turbo Mag article on pullies for the 350z

 

[boomergt]

So does anyone have any comments on Zivman post above????

 

[Brian MP5T]

The TB thing would help a NA car out more that a Turbo, that being said, I have heard good things for both types of applications. There are several "Discussions" about the Underdrive, and we have come to the conclusion that it's a bit of a waste. There is more "Ass Dyno" results than actual results. Plus, you can shake so much more off with a flywheel that costs the same...