Atomic Motors (Merged Topic).

[Kimberley Scott]

That's an excellent post from Nizpro..... thanks.

Could I get you to clarify whether 650 lbft peak torque is for stock rods, or for an aftermarket rod.

I can see a lot of guys are going to be checking their dyno charts to see where they sit.....

Here are some conversion factors which might help.....

650 lbft equates to about 880 Nm, based on a conversion factor I found in a text....

1 Nm = 0.73756 lbft.

For those that want to get an indication of the torque from their power charts...

  Nm = (kW x 9549) / rpm

so, if you have 220 kW at 3000 rpm, then that equates to 700 Nm @ 3000 rpm

That also equates to 516 lbft of torque in the old imperial measurements.

But if you have 200 kW at 2000 rpm, then that's over 954 Nm @ 2000 rpm

which is equivalent to 704 lbft of torque...

As Nizpro have stated, it's all well and good to get a big kick in the pants with a huge torque peak at launch, but it's much safer to control the peak torque down low, and aim for a flatter torque curve across a wider bandwidth for good reliable street use.

Some guys are finding their ET's at the track are better by early shifting to take advantage of the higher torque at lower rpm......  This is fine IF the motor and driveline can take up the stress due to the huge increase in peak torque.

tom

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Any chance you can help me out with the sums on mine?

Scotty

[F6 RAPID]

I can Scotty - not enough, you NEED more!

you know you want it.

[Kimberley Scott]

I know.

Scotty

[Kimberley Scott]

What Rpm is 160m kph in 4th, I am trying to work out the tourque.

Scotty

[SavageF6]

As well as all the ratios, you'll need the diameter of the rollers on the dyno then.

[Guest]

Lean mixtures on there on will not cause this type of failure due to the fact that cylinder pressure will be reduce due to the lack of combustible mixture. This is one of the key point I have shown on the engine dyno to all who have attending our training seminars. I am usually looked at with discussed when first explaining this, as people are very reluctant to believe that in some cases a richer mixture will actually cause the onset of detonation . Mind due once shown people are simple amazed.

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finally someone agree's with me!!!!!

as to the main reason I have seen for rod failure its been rod bolts

cylinder preasures due to torque have not been an issue for me but

seen a lot of bent rods due to detonation though

[jetute]

ok

so by this thread we know the rods are not up to the task.

-most people say that rods and pistons need to be changed at a minimum and maybe bearings??

now what are the options??

for those that have the money to fork out for rods and pistons what is the best way to go?? what brands and what prices??

what about if if wanted rods only (I know I know.. do the whole lot if you have it open). but if you were to do this.... which ones? if the rest remained the same.

opinions

[GOLDIE]

Hey jetter I use atomic rods and cp pistons also acl race bearings.

As for rods alone atomic again and bearings the same but not worth the hassle with out the pistons.

Ian

PM for prices

[Adam]

Firstly to make your decisions you would have to know how much power you want to make, not just now, but in the future.

Pistons, who knows?

Conrods, Atomic rods are up to the task by all reports.

Bearing, I would change the bearings without a doubt.

I for one would consider changing just rods, due to a couple of reasons.

I could do the work myself and the cost would be realistic for me. Pistons would at least double the cost of the job.

I also decided long ago that I wanted 300-315rwkw's, that's approaching the point of rods according to the general opinion and I'd like the piece of mind knowing that it can be tuned and driven more aggressively.

That's my thoughts, I'm sure everyone will be different but that will depend on their ultimate goals and budget.

[jetute]

Hey jetter I use atomic rods and cp pistons also acl race bearings.

As for rods alone atomic again and bearings the same but not worth the hassle with out the pistons.

Ian

PM for prices

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thanks ian... I will get in touch about this stuff but the time is not right at the moment.

as for rods alone... when you say not worth the hassle without pistons... does that mean that there will be issues if rods alone are done?... or that since its open may as welll do both?

when the time is right I will give you a call