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To claim rwkw is the wrong part

Fair point - gotcha. I think people say rwkw as a matter of habit :nyaanyaa:

BUt the moroso calculator doesnt lie, MPH and mass tell it all. Why not take it to the drags, measure the weight, thats the sure way to know how much power it has. By the shape of the power curve, i would agree with nismoid, if it was making 250rwkw on 8 psi then the boost threashold would be higher with a different shape curve.

Moroso is a calculator based on estimations and assumptions. A dyno is far more direct... an engine dyno is the only thing that tells you how much a motor makes. The drag strip is the only thing that tells you how fast it is down the 1/4 :thumbsup: Most people these days are savvy enough not to claim their car is quicker (or not) based on whatever the dyno spat out. Otherwise I'd probably be pretty keen to get on the lowest reading dyno anywhere and take the credit for being a better driver than everyone else haha

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From what I understand though the Moroso calculator is quite accurate?

And you cant play with settings of a drag strip like you can a dyno either...

Cant really add any 'correction' to top end MPH :nyaanyaa:

From what I understand though the Moroso calculator is quite accurate?

And you cant play with settings of a drag strip like you can a dyno either...

Cant really add any 'correction' to top end MPH :nyaanyaa:

But you can enter whatever you want into the calculator :thumbsup:

But you can enter whatever you want into the calculator :nyaanyaa:

Well then your only kidding yourself, the only genuine way to back up the power level is to know the MPH, and that has not got much to do with launch etc. We have seen time and time again power claims on here that cant be backed up with a trap speed.

I just found one of my time slips from a few ago weeks ago. On a wet day where the track was slowly drying up and I had unwarrantable tires in the rear, my best trap speed was 114mph. My ET for that particular run was 14.1. I was constantly wheel spinning through second and third the whole day. I ran a 14.1 with the old standard RB20DET I had in my car previously, so I reckon she has some good ET numbers in her under optimum conditions (good track, good tires).

Well then your only kidding yourself, the only genuine way to back up the power level is to know the MPH, and that has not got much to do with launch etc. We have seen time and time again power claims on here that cant be backed up with a trap speed.

MPH alone is not enough to determine power output, there are too many variables.

Why dont you clear it up and take it to another Different Dyno? just for a power run, then get the graph modeled in power vs psi(boost) then you can clear it up

Why dont you clear it up and take it to another Different Dyno? just for a power run, then get the graph modeled in power vs psi(boost) then you can clear it up

I don't think there is anything to clear up. Keep going to the same dyno and you can compare your own progress with yourself. If you want to see how fast it is - you race it. There is varience between most dynos anyway, so there is no point measuring using someone elses stick... because there is always going to be someone who says the reading is "wrong".

A before and after is what dyno's are good for.

Now the car has a new turbo and more power than before it's time to see how much quicker it is. Thats the fun part and the bit that really tells you how well setup the car is.

Unless you are a dyno queen of course :(

Tell you the truth i am far from impressed from that dyno graph. Sure you made 252kw, but it's at the end of the rev range at a short peak burst, ok for dyno comps where only peak power matters, but shit for street driving and other events. I much prefer a "fatter" graph, one that has more usable power, this is were a ball/roller bearing turbo has it's advantages, as it spools up faster. Your result also depends on the size of your turbo as if it is a big turbo, i would assume 8psi is not even tickling it's efficiency range. Get some bigger injectors, change the w/g spring to 14psi, retune the ecu and see what happens :(

A graph of you boost response will help clear things up.

Here is a graph comparison between our cars, neglecting what people have stated about "hub dyno's read higher, etc...". Also keep in mind i am using 18psi on a 380hp turbo

post-1811-1186808285_thumb.jpg

who cares

Ppl use hub dynos as they are a more accurate and consistant chassis dynamometers at measuring power at the wheels, since wheel diameter, tire pressure, and tire slip or bounce off a roller plays no factor in the measurement of power at the wheels - the dyno is a tuning tool remember so consistancy important. They will read higher than a roller and this differnece increases with power output. However Iits unrealistic to think this reading is 25% because of the dyno type at these power levels, most likely do to something else.

250 on 8psi psi...yeah I would expect more like 210-20 myself with this setup.

Here is a graph comparison between our cars, neglecting what people have stated about "hub dyno's read higher, etc...". Also keep in mind i am using 18psi on a 380hp turbo

The reason your power delivery is so much fatter for most of the graph is you are running 18psi......

The reason your power delivery is so much fatter for most of the graph is you are running 18psi......

Well that's what i am saying though.........

With such a low boost setting, on an aftermarket turbo, you will not be using the turbo's potential.

To make 250rwkw@8psi and using an external wastegate only tells me that he has a biggish turbo (500+hp). No point being happy with 250rwkw when you can't use it, unless you're on the limiter; and when there is so much left in the setup.

On a side note: Are you saying that the more boost you run in the same turbo the more responsive it is? Is that true? I would have thought that the response would be the same till 8psi, then the engine just doesn't make as much power, follows the same line but at lower power ;).

Are you saying that the more boost you run in the same turbo the more responsive it is? Is that true? I would have thought that the response would be the same till 8psi, then the engine just doesn't make as much power, follows the same line but at lower power :).

Ahh ok I was just making sure that was clear :)

And in no way am I implying that running more boost would make it more responsive! I was just making sure that it was clear that a big/plain bearing turbo won't be giving anything away to a small BB turbo in fatness of power delivery once its at the same boost level. It'll obviously take a bit longer to get there....

Generally, what sort of trap speed represents 250rwkw down the 1/4 mile? Keeping in mind this is in a Silvia chassis (so pretty much the same as an R32 Skyline)?

giving u an idea, i ran my r33 gtst with similar power, 60 foot time of 2.3, et of 13.3 and termial speed of 112mph :)

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