Jump to content
SAU Community

Recommended Posts

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

  • Replies 42
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

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 :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
    • For race cars, this is one part where I find having the roll cage bar having gone through a hole in the floor better than the build it up on a ledge inside... The Merc I help on, the main hoop ends are marked on the car, and the jack is marked... Jack goes under a few inches and lifts one whole side of the car up... Removes that fight for long slim jacks for race car duties!   My biggest issue for the daily drivers I work on, is my jacks don't go high enough. The jacks start out on a few blocks, jack it up, then start a second jack under it on more blocks, and then I can get an axle stand under it. My axle stands are presently in use, and are nearly fully extended. The car is sitting with barely more than a cm of clearance to get the wheel off the studs! Sarah's Kluger is the same, as it has an ungodly amount of droop available in the suspension and a distinct lack of good jacking points!
    • Happy? Yep, my to do list is getting shorter and shorter. Either this light approaching is the end of the tunnel, or I'm about to be hit by a train... Ha ha ha   Also, Duncan isn't that far out of town that you need to make a multi day drive out of it. 😛
    • Sorry I meant that we are building the EH for a client.
    • LOL, when one "money pit" is never enough Noice, and excellent work mate
×
×
  • Create New...