Made it to the dyno

[thehelix112]

Well, I will test them for sure, as said I am over 600 crank hp now..

 

Did I miss a post where you went back to the dyno? Or are you going with the well-worn net-boy's guide to dyno figure inflation? I would have to question what sort of driveline you're running if you're going to claim 25% loss, or have you since had the engine on an engine dyno to support that claim.

 

Forgive me for asking, just well, you know, seeing as you don't seem willing to believe anyone else has made hp without proof?

 

Dave

[TimZ]

Tim may I ask how much money you have in your engine?

I stopped counting long ago.

 

If you are already setup for the T5, you might want to look into the GForce T5 gearset - mine has been holding up really well. You'll need a WC gear housing (the datsun bellhousing and tailshaft house bolt right up), you'll need to modify the tailhousing for the larger output shaft, and of course you'll need a new drive shaft and clutch hub.

[1 fast z]

17 percent drive train loss, makes right about 600 hp. Thats the closest percent loss I have read for years on these cars and trans/rear end, sticky tires, etc. No I will definitly be using the Z32 trans, as I already have it, I already have an adapter, also. I will try it first, although, it is REAL heavy. I dont have tons of money, and I want to keep the TOTAL cost including the car under 5k. I am at about 3400 now. Paint should put me right at my 5k mark when Im done. My goal is to get low tens if not high nines with the car when Im finished on pump gas. I will be building a cage soon for the car also.

[jgkurz]

I stopped counting long ago.

 

If you are already setup for the T5, you might want to look into the GForce T5 gearset - mine has been holding up really well. You'll need a WC gear housing (the datsun bellhousing and tailshaft house bolt right up), you'll need to modify the tailhousing for the larger output shaft, and of course you'll need a new drive shaft and clutch hub.

 

My G-force T5 is also holding up well. It's taken plenty of punishment and hasn't missed a beat. The only down side is the gearset is much noisier than stock. For me the durability was well worth the extra noise. I had mine built with some extra strength items like a G-force reinforced case so I can use it in a Bonneville LSR application someday. It's suppose to hold well above 600bhp but there are never any guarantees....

[Clifton]

600 HP is all the stock rods are supposed to be good for? Hmm. I remember when people said that about stock 2JZ pistons and rods a few years back. Now people make an easy 800+rwhp on them. My 91mm stroked 7m with a rod that can't be any stronger than an L rod has been easily doing more than that for years.

 

Bryan, I would talk to Joel. It might not be too much to buy just the cold sides you want.

[1 fast z]

I just picked up one .48 ex housing on ebay, so I need one more. I will talk to joel this week. Yea, I would guess rod failure from detonation, etc. But to put a pure HP marking on a rod is pointless. Its TORQUE output that is harsh, not HP. It all has to do with R/S ratio, lenght of rod, timing, etc. There is ALOT of varibles to be looked at. I tend to do things that alot of people say I cant or couldnt do. I learned ALONG time ago, that internet talk is just that, talk. I like to experience it FIRST before I belive it, to an extent that is. I mean, 90% of the guys on this board, said I couldnt bolt a head together, and make it last, and 5k miles later, and nealry 500 rwhp, holding up great.

 

 

So what does happen when at 600 hp, the rods fail? What fails? Pictures? Bolts, bending, cracking????? Lets get technical about it if where going to throw it around online.

[Gollum]

I remember watching a video (linked on THIS website) of a BMW inline 6 reaching the limits of the stock rods of the motor around 700hp or something.

 

They had a pic of all the rods laid out and you could see which one failed as it was bent badly.

 

They said they were gonna replace the rods and shoot for 1000hp.

 

Though that's not extremely scientific data, sorry. It's the best I've got off the top of my head.

[(goldfish)]

One of the ZOOM club members has eaten 2? trannies on his z32 at the 600hp crank number.

[WEBEZEEed]

I can't even come close to say how much H.P. would do this or how much H.P. would do that, but MY GOD....... to risk all that work in that head to find out! (woweee)

[Challenger]

Im guessing that a rod failure could damage the head? Will the head be easily fixed if something was to be damaged?

[Thumper]

One of the ZOOM club members has eaten 2? trannies on his z32 at the 600hp crank number.

 

I think 600hp in s30 is alot easier on the tranny since you are accelerating alot lighter vehicle. So more power is wasted on accelerating the parts then moving the vehicle vs a heavier car.

[1 fast z]

Agreed. F=MA, less mass equals less force. Make the car lighter, makes parts stronger. Sorta like lighter pistons make stronger rods, etc.

[rztmartini]

that really makes sense, considering how much you lightened your pistons...

so i dont think that any of the other rod limits would apply to you, unless they had the same weight pistons...

 

btw, if you dont mind to share, what was the difference in weight btwn the stock piston and yours?

[1 fast z]

I cant remember the exact per piston but I did take out 2.9 lbs out of the recipcating mass, compared to a flat top nissan setup.

[Tony D]

"600 HP is all the stock rods are supposed to be good for? Hmm. I remember when people said that about stock 2JZ pistons and rods a few years back. Now people make an easy 800+rwhp on them."

 

The difference is the 2JZ was people without any experience on the engine making the claims. The difference here is someone like John Caldwell of Electramotive found out failures firsthand in the 80's. They may have been detonation related at that power level, but they would not use stock rods in endurance engines, and those classes that required stock parts got changed regularly....like NHRA Top Fueler Parts.

 

Making 600HP on a run down the dyno, and 100 passes down the drag strip is only maybe 10 laps of a road course. Drawing conclusions on durability this early in the development stage is foolish, especially when others with far larger budgets decided they were not going to risk their engines (or race winning record) on a properly-prepared stock rod. And this was the best in the busines making this decision...

 

The rods were a compressive failure as I recall, splitting down the H-Beam beneath the gudgeon pin.

 

JeffP does not have stock rods in his engine, either.

 

Our Bonneville N/A engine walked the pressed-fit pins to the wall... Stock rods seem to get slightly 'elastic' on the small end above 8200rpms, and then have compressive issues at the BMEP encountered at or above 100 HP/ Hole. You freshfaced engineer-types should easily be able to calculate that BMEP point on the bore diameter, I'll leave that to you, see what you come up with!

 

And remember this is true engine HP that can be extrapolated back to SAE standards. A Mustang Dyno can be back-extrapolated, most Dynojets are not set up for that kind of accuracy. So the type of dyno you run on will inflate the numbers as well. KTM will verify the difference between the HP shown on the Mustang at Dynamic in Lake Forest and the DynoJet at DRS in LaHabra can be startlingly different: 20-25% in some cases. Even Dynamic's Owner said he will warrant you show at least 15% more HP on a Dynojet than what you will read on his Mustang. But his Mustang is calibrated and traceable to a Set Engineering Standard set by the SAE, so take that FWIW. If JeffP wanted to do the brag thing, he would be using his Dynojet numbers, not his Mustang numbers...that would put him above 570 RWHP, misfiring like crazy about 6300rpms.

[X64v]

I think 600hp in s30 is alot easier on the tranny since you are accelerating alot lighter vehicle. So more power is wasted on accelerating the parts then moving the vehicle vs a heavier car.

 

F=MA, less mass equals less force.

 

I politely disagree with the above statements. Force is dictated by the output of the engine, not the mass of the vehicle. Less mass equals less force for a given acceleration, but not for a given engine output. If you put 600ft.lbs. of torque through a tranny, it does not care what it's trying to move. You're not moving as much mass, but you're going to get better acceleration, making the stress on the tranny the same.

 

The lighter pistons analogy is not the same, as acceleration is held constant, dictated mostly by engine rpm.

 

The point is moot, as you're using that tranny no matter what, but none of us like incorrect information floating around.

[JohnH]

Show me ANY L Series with over 600 RWHP, everyone keeps talking about them, but I wanna see legitimant proof.

 

 

I posted some youtube vids of JDM cars on the other board a couple of weeks ago. Check under "bunch of Jap vids" in cartalk.

[1 fast z]

No, I dissagree. If you make a car lighter, the DRIVETRAIN COMPONENTS ARE STRONGER, it IS the same as if a lighter piston is on a rod, it makes the rod stronger.

 

 

 

You take a car that weighs 10,000 lbs, with 500 torque, and get sticky tires and launch, then take the SAME motor in a car that weighs 1000 lbs, the car that is ligther, will be less force on the drivetrain.

 

 

Take a slege hammer, leave it on the ground, then with one arm, take it and as fast as you can swing it 360 degrees over your head.

 

 

Then take a tack hammer and to the same thing.

 

 

Post your results back when your done with the hammer testing.

[thehelix112]

You take a car that weighs 10,000 lbs, with 500 torque, and get sticky tires and launch, then take the SAME motor in a car that weighs 1000 lbs, the car that is ligther, will be less force on the drivetrain.

 

Unless the 1000lb car accelerates 10 times as fast as the other car, which I think may have been X64v's point.

 

There is a reason transmissions are rated in torque. Assuming that 100% of the torque is used (and not lost in say, tyre slip > 1), both cars will pop the transmission at the same time.

 

Dave

[X64v]

Your piston and rod analogy is true, but does not relate in the same way.

 

That car that weighs 1000lbs will accelerate 10x faster than the 10,000lb car, because the force is the same.

 

The hammer example is the same as the piston and rod thing. You're holding acceleration constant while varying the mass, which varies the force. This is not the same as the two different mass cars with the same force applied. The force on the car (generated by the engine, transmitted through the drivetrain) is the same in both cases. Cut the weight in half and you double the acceleration, not cut the force in half.

 

Edit: Dave beat me to it.