Another Dyno thread

[paulr33]

Most people know that I always look for and generally find a reason for freak results. I believe there is always an explanation/reason. I sit and study the data logs from the race cars for hours looking for reasons, hints, symptoms etc anything that will give us a competitive edge. So, sorry if the following appears a little harsh but it is based on what I see.

Hi Paul, I agree with Cubes, your power flattens off over 5,250 rpm, you should be up around 200 rwkw at 6,300 rpm based on the lower part of the curve. A properly tuned and set up RB25 with your mods makes it max power around 6,250 rpm and yours looses 15 rwkw instead of increasing power in the last 1,000 rpm. It is good up to that point, as good if not better than most. That's why it feels fast.

My guess is you have a restriction that is limiting the flow over 30 lbs per minute of inlet airflow. Or more likely, an exhaust restriction that is limiting the out flow. My first suggestion would be to take a critical look at your dump, engine pipe, cat and exhaust. Maybe even try a dyno run with it disconnected at the front of the cat. That will tell you where to start. At the same time take a close look at your boost curve, particularly what is happening under and over 5,000 rpm. I try to take a boost pressure reading at the turbo oulet and compare that with what I see at the plenum. If there is more than 1 psi difference between above and below ~5,000 rpm then you have an inlet restriction. Have a critical look at your filter, intercooler and inlet pipework.

When looking for an issue like this, I just do one power run and log everything that I can. Costs very little, if you do it at a club day $50 or so. Then it is time to look at the tuning, what are the A/F ratios like over 5,000 rpm? What are the ignition timing settings over 5,000 rpm? Have a look at the maps on the Commander and just do a simple comparison while refering to the dyno graphs. The answer is there, I guarantee it.

Hope that made sense:cheers:

ok stupid questions when you get a front and dump pipe done and fitted they change the pipe that has the oxygen sensor on it don't they? looking at my car the pipe that has the oxygen sensor on it appers stock (its probably 20cms long??) - this is the dump pipe yeah? then if so ive still got the stock dump pipe. 20cms down i can see a new pipe which looks to be 3" then it goes under the car. i remember seeing under the car that i saw the new pipes but never checked the dump pipe area

[paulr33]

ignition maps on the way, hang 5

[justin911]

when i got my exhaust there was a hole for the oxygen sensor to go in the new exhaust. Mine was a r33 bolt on kit though. There was just 1 long pipe that went from the turbo to the cat if i remember correctly.

[paulr33]

http://members.dodo.com.au/paul/docs/power...-%20paulr33.xls

[predator]

The stock "dump pipe" - or one off the turbo has the O2 sensor.. unless you have an aftermarket one (not all aftermarket are one piece). Usually the factory ones are cast and have a browny/reddy colour by now.

If your stock dump pipe is still factory, I would say thats probably an obvious restriction..

[Cubes]

Paul,

Do a full power and Map trace run through say second gear. Take note of the load points it uses.

Let me know.

Edit: Just in case you don't know.

On the hand controller go in to Monitor, Maptrace then press the right arrow key. This will mark every load point you use.

I'm comparing the map to a stock map with comments to show you where the differences are and by how much.

I'll post the map tomorrow.

[paulr33]

no probs, will do map trace today

[paulr33]

http://members.dodo.com.au/paul/docs/power...-%20paulr33.xls

[C yar]

*** not meaning to make examples of people or anything. i took 4 other non powerfc or aftermarket ecu dyno runs from the rb25det dyno thread and put them below ***

 

heres my latest dyno. after powerfc knocking fix.

my peak power goes between 130km/h to 180km/h redline of 4th.

my max power looks to be much more than the safc/stock ecu combo's below.

**** it i dont my max power is lower. my average power is much better than the non powerfc configurations (4 below).

http://members.dodo.com.au/paul/pics/dyno/172rwkw.jpg

 

http://www.skylinesaustralia.com/forums/at...achmentid=25688

203rwkw

mods

3" exhaust

pod filter

10psi boost

safcII

FMIC

BP Ultimate 98

stock standard turbo

 

http://www.skylinesaustralia.com/forums/at...achmentid=25736

185.5kW 93 series 1

Engine management - Stock ECU

Boost ran - 0.9 Bar

Turbo - Stock

Fuel used - Optimax

Stock all other internals.

Apexi AVCR

Hybrid Front Mount

3" Exhuast from dump pipe back

Pod Filter

HKS SSQ BOV

 

http://www.skylinesaustralia.com/forums/at...achmentid=25752

1994 R33 GTS25t

Avcr - 0.8bar

Full zorst

Trust IC

Standard Turbo

Standard Ecu - no tuning or piggybacks

Automatic gearbox

180.3 Rwkw

 

http://www.skylinesaustralia.com/forums/at...achmentid=25791

1995 gts-t

Stock turbo

pfc

gtr fuel pump

adj fuel press reg

3'' catback exhaust

ebc

Pod filter+partion

Small Hks front mount

Slipping stock clutch,leak in header/exhaust gasket.Cant remember what boost it ran...

12:1 afr's

182.0rwkw

 

 

http://www.skylinesaustralia.com/forums/at...achmentid=26012

Iv got 172rwkw S1 R33 Auto

Stock turbo

Stock cooler

10 psi

Cat back zorst

Pod

Auto Tranny

ok the top dyno is my car, my hp jumped heaps when we fitted the SAFCII,

I have to agree with nickr33 about the nasty holes in the power curve and yes it was time for a powerfc upgrade...

the mid range power you talk of... well my car on the road had little mide range and little power until above 5000rpm then the power kicked in pretty hard

by the way i have had my car on 2 different dyno with same figures

NOW.. like i said before it is time for a ecu upgrade.. i now have a power fc and gezzz it made a huge difference... not only in max power 290hp (216kw) but in drivability.... meaning more power midrange and accels heaps better

not sure if ive added any heapfull info but .....

[Munna]

im gonna jump up and agree, my rb25 that manages 0 to 100 under 5 seconds only gets 170rwkw only 2 seperate dynos'. ice performance checked it out and its fine. making the normal amount of power. powerfc, boost@0.80bar, cooler, zorst, dump/front/cat 3" so the usual mods. however ive seen stacks of cars with just safc or remap hit 195 all the time. so either the dyno's are on crack or shootout mode is off the scale or my tune is shit. or something is wrong with my engine. now im not trying to be the "winge winge rb25" guy sure my power less so be it, there must be a reason surely.  

 

now i know that an rb25 with safc (or remap) and exchaust cooler may make 195rwkw at max but im sure my 170rwkw max top figure should out acceralate the safc tune as the powerfc tune is more aggressive, well theoritcally speaking it should be? i guess the only resolution is a dyno day and do change any of the dyno settings for the day. the freak "ecu" thoeory has been thrown around a bit and i remember sk shooting it down a few times, theres always something that is the reason for the "freak" power output. maybe servicing history or some crap has made the engine stronger. my rb25 is on 120,000 odd so i wouldnt call it "old old" but it certainly isn't new.

Power in sig dynoed at Ice performance. Car has 79000 on the clock dont know if its genuine K's but is in top condition

[TTT]

did anyone else notice that Paul R33's car is an AUTO?

doesn't this make a difference to power at the wheels?

don't they have different ratio's?

and how do they keep it in the gear that is 1:1 ratio as the auto kicks back if floored.

just a thought.

[nedb]

I just had my Auto R32 tuned. It made 168rwkw.

Mods are: pod, 3" full exhaust, RB25 turbo and FMIC and 14 psi with GFB bleed valve.

FMIC alone made 14rwkw difference on stock boost. (144rwkw on 10psi)

At the same time there was another R32 manual, with RB25 conversion with pod, exhaust and FMIC and it made 160rwkw on stock boost (7psi)

[Turbine]

How about this theory Roy.

I'm putting it down to the way in which the available airflow gets through th system to the engine.

In the past if you looked under the bonnet of a modified street car, it would have all the good names on it but no thought about how the airflow gets around. Nowadays with the same good names of harware, guys are streamlining the airflow path.

This makes less heat, less restriction and so on to develope more horsepower.

May have a little to do with the tunning ability of the guy as well

Turbine

[Sydneykid]

We have picked up quite a bit of power with Optimax and Ultimate now being more readily available and also safe to tune to. Plus we are tuning tighter around the A/F ratios and we know we can rely on the knock sensors, so the ignition timing optimisation is more confident. We are using faster/more accurate lambda sensors so we have reduced the allowances.

As for the cars themselves, well I will pick up on one point, heat shielding and ambient air feeds. We would hardly ever see a car with a decent heat shield and air feed, open pods sucking in hot air were the common sight. Not so much now, but still too much for my taste.

Plus I reckon I have picked up 10 rwkw from reading the forums (this one in particular) and implementing the good ideas of others. Don't underestimate the power of pooling knowledge.

[WazR32GTSt]

I just had my Auto R32 tuned. It made 168rwkw.

Mods are: pod, 3" full exhaust, RB25 turbo and FMIC and 14 psi with GFB bleed valve.

FMIC alone made 14rwkw difference on stock boost. (144rwkw on 10psi)

At the same time there was another R32 manual, with RB25 conversion with pod, exhaust and FMIC and it made 160rwkw on stock boost (7psi)

i'd be keen to see a dyno graph of your auto R32 making 160rwkw

i made 132rwkw with the auto rb20 having 3"dump/front/cat-back (stock cat), FMIC, 12psi, chipped ecu (AFRs were 10-10.5 though), rb26 cams, and panel filter with CAI

i thought the auto robbed some power out of it personally but you seemed to do nicely!

EDIT: actually i just noticed in another thread that you have the MV automatics shift kit in your auto box as well... was this put in after the 140rwkw run?

would this have contributed to the dyno figure or is it purely gear changes as the name would imply?

[WazR32GTSt]

I just had my Auto R32 tuned. It made 168rwkw.

Mods are: pod, 3" full exhaust, RB25 turbo and FMIC and 14 psi with GFB bleed valve.

FMIC alone made 14rwkw difference on stock boost. (144rwkw on 10psi)

At the same time there was another R32 manual, with RB25 conversion with pod, exhaust and FMIC and it made 160rwkw on stock boost (7psi)

actually i just noticed in another thread that you have the MV automatics shift kit in your auto box as well... was this put in after the 140rwkw run?

would this have contributed to the dyno figure or is it purely gear changes as the name would imply?

[paulr33]

did anyone else notice that Paul R33's car is an AUTO?

doesn't this make a difference to power at the wheels?

don't they have different ratio's?

and how do they keep it in the gear that is 1:1 ratio as the auto kicks back if floored.

just a thought.

its not auto, where did you get that idea from? i need to find a workshop who do me a dyno run with the exhaust disconnected to see what power i make with the exhaust off

[TTT]

ummm...

from the post that you put up..

http://www.skylinesaustralia.com/fo...achmentid=26012

Iv got 172rwkw S1 R33 Auto

Stock turbo

Stock cooler

10 psi

Cat back zorst

Pod

Auto Tranny

where it says "I'VE GOT"

I assumed that meant that YOU'VE GOT since you are the one posting.

[paulr33]

thats not my car, it was someone else's i was posting the config (and 4 others) as examples

[The Mafia]

I made 209rwkw, and 420nm Torque NOT in shootout mode, done on 2 different dynos.

Is that good?

PFC

FMIC

Pod filter & Partition

12psi

Full Custom Exhaust and Hiflo Cat

Standard Turbo, Standard Injectors, and Standard Fuel pump.

Same mods without the powerFC made 141rwkw at 10psi

I don't give too much of a shit about top power. I want torque..