nos and sc?

[diablo2469]

anyone know anybody running a supercharger/turbo AND NOS? what is the hp limit of the NSX engine?

 

[David]

Originally posted by diablo2469:
anyone know anybody running a supercharger/turbo AND NOS? what is the hp limit of the NSX engine?

If the N2O is properly tuned, there is no reason you should have any problems. In fact, the cold N2O will lower your intake temperature. Just be sure to pull enough timing. And, of course, use a wet shot.

The hp limit is not an exact figure. On the stock bottom end, I would be hesitant to go over 450 hp with a 3.0L and 500 hp with a 3.2L. One of the problems is that it is not immediately obvious when you are flexing the block. In the cases I have seen, it takes 10-15K miles to fatigue the block, so you won't have problems unitl maybe a year later. Unfortunately, once the block is fatigued, it is junk.

My .02.

 

[Sig]

What do you think about this scenario in the BBSC?

At WOT, use a small 50 shot to spool up the blower from about 3000 or 3500 rpm up to about 6000. At this point lay of the N20 and let the top end power of the bbsc take over.

This will give low-end grunt and hp up to the point where the bbsc starts really coming in.

Any downsides to this?

 

[Factor X Motorsports]

We agree with David's thoughts on NOS/SC and have been running a wet shot on top of the CTSC for the past 2 months. We've been pushing over a bottle a week

Speed Safely,

Factor X Motorsports

 

[David]

Originally posted by Sig:
At WOT, use a small 50 shot to spool up the blower from about 3000 or 3500 rpm up to about 6000.

You can't "spool up" a blower. It is mechanically driven. Sorry.

 

[Sig]

Pardon the poor word choice, or shall I say incorrect word choice. What I was getting at is the additional horsepower and torque from a small n2o shot will get the motor to the power band of the bbsc blower faster than without n2o.

In addition to getting to the power band faster.... I would think that since the bbsc dyno plot demonstrates that the power curves of the bbsc are almost identical to an otherwise stock car, a nitrous shot in the rpms leading up to the powerband would significantly add to the overall power under the curve. Total power under the curve being on of the most critical aspects of overall acceleration.

[This message has been edited by Sig (edited 03 May 2002).]

 

[David]

You could put a Hobbes switch on it so that it would shut off at a particular boost level.

 

[Yellow Rose]

On the stock bottom end, I would be hesitant to go over 450 hp with a 3.0L and 500 hp with a 3.2L.

******

Are the above HP numbers at the flywheel or at the pavement?

Regardless, other than the bore, the bottom-end of the 3.0L and the 3.2L are the same, right? Therefore, why your hypothesis of the variance of max HP between the two engines?

No flames, just seeking knowledge.

 

[4g62bt2c30a]

Originally posted by AndyVecsey:
On the stock bottom end, I would be hesitant to go over 450 hp with a 3.0L and 500 hp with a 3.2L.

******

Are the above HP numbers at the flywheel or at the pavement?

Regardless, other than the bore, the bottom-end of the 3.0L and the 3.2L are the same, right? Therefore, why your hypothesis of the variance of max HP between the two engines?

No flames, just seeking knowledge.

FRM?

 

[David]

Originally posted by AndyVecsey:
why your hypothesis of the variance of max HP between the two engines?

Andy,

That is a really good question. I am not really sure there is one (a difference), and the block tolerances may be the same.

The two motors that I have (reasonably) good data on were both 3L and failed at between 10K and 15K miles. One was making about 450 hp at the wheels and the other just under 500 hp. Both exibited the exact same symptoms and both had fatigued blocks. I am just hesitant to scare any 3.2L owners into doing Darton siamese style sleeves or a block guard when they might not need them. The 3.2L motor has slightly better sleeves (for moderate hp levels) and also, in my experince, larger displacement motors are often able to make more hp with less stress. As I stated at the begining, however, this may not be true for the NSX, as the motors are very similar except for the piston diameter and the sleeves. They blocks may very well fatigue at the same hp levels. Who can say for sure?

Its just so hard to tell, becuase it is almost impossible to diagnose before it is too late. The motor would seem perfectly healthy until you started having mysterious problems with the bearings or rotating assembly.

[This message has been edited by David (edited 04 May 2002).]

 

[cojones]

Originally posted by Sig:
the power curves of the bbsc are almost identical to an otherwise stock car

The plots from the recent NSteXpo dyno day seem to indicate otherwise (right Andy ?). Depends on the RPM range in question, and your particular driving application.

 

[cojones]

Originally posted by David:
I am just hesitant to scare any 3.2L owners into doing Darton siamese style sleeves or a block guard when they might not need them. ...

As I stated at the begining, however, this may not be true for the NSX, as the motors are very similar except for the piston diameter and the sleeves. They blocks may very well fatigue at the same hp levels. Who can say for sure?

Its just so hard to tell, becuase it is almost impossible to diagnose before it is too late. The motor would seem perfectly healthy until you started having mysterious problems with the bearings or rotating assembly.

Is the cost of prevention (decking the block, lower comp pistons, sleeving, etc) a worthwhile investment, rather than a block replacement down the line?

Also, once you get into (some) reinforcements, do you open up some alternatives towards increasing displacement ?? Up to a 3.5-3.8L with a 3.0L, which would probably be preferable to a stroker job on a 3.2L

 

[David]

Originally posted by cojones:

once you get into (some) reinforcements, do you open up some alternatives towards increasing displacement ?? Up to a 3.5-3.8L with a 3.0L, which would probably be preferable to a stroker job on a 3.2L

Since doing it correctly means new sleeves and pistons, yes. You could go as wide with the bore as the machine shop thinks will work.

If you want to increase the stroke, there is room, but it gets very expensive. At that point you are talking about new rods and a custom crank. Plus, you would have to machine out the block a bit for throw clearance.Anything can be done with enough $ - a friend of mine builds 2.8L H22s. : )

[This message has been edited by David (edited 04 May 2002).]

 

[nsxlr8]

hey Dave. .....

What part of the block got fatigued?
Was this under boost? What psi?


Do you mean the cylinder liners?
Did they (Liners) split at the top typical of a fully jacketed aluminum block Honda?

The main bearings? - fail?

Were these your engines?

Not trying to bombard you at all here, just giving you an idea of what I'm looking for. : )

Thanks in advance.
BK