YBJ

iTrader: (3)

I hope someone can answer this as I did a search but couldnt find an answer.

Car is a cossie 4x4 with brandnew T34.55 turbo running and MSD 380 bhp setup for siemens 55's. At the road boost pressure peaking at 32psi holding 26 psi (high setting) and 18psi (low setting). Car pulls like a train.

Now yesterday I have been to a Dyno an the result (flywheel power) are:

high boost 300bhp at 26psi and
low boost 218bhp at 18 psi.
So I am very dissapointed to say at the least.

Have to say this: I have mounted an air temp prob before and after the intercooler to check. The car was running at least 20min at idle because of strapping down issues. Intake temp after intercooler were rising to 63.5 degrees Celsius. I also heard the coolings fans for the radiator go on.

Run was taken with this temp and didnt go down. Boost was also decreasing rapidly after peak so not holding it. Now I think these very low figures are pure due to the very high intake temperatur.

At which temperatur does the ECU retard the ignition? And does it also reduces the boost pressure out of savetiness?

Again at the road I do not have these issues and inlet temps stays under boosting around 20-25 degrees (ambience temp being around 13 degrees celsius)

Hope someone can tell, here is the graph:

Danielbetty

iTrader: (3)

Them figures at the wheels or flywheel?ive hot simuliar set up and mine made 385bhp on Harvey's dyno

Jay,

iTrader: (4)

the ecu should retard ove 40 degree and itll be mapped accordingly

Turbosystems

iTrader: (5)

you won't get much power with act's at 60 +
who left it ticking over so long all this will do is cause heat soak
your act's should have come down quickly once on boost
ign retard is not the issue with your power loss high act's have less oxygen by volume
and it is oxygen you need

YBJ

iTrader: (3)

This is flywheel power measured. I edited my post.

scoooby slayer

iTrader: (4)

stick the graph up.

stevieturbo

Ask whoever mapped it what sort of timing compensations are applied.

And it almost reads as if the dyno had no cooling fans ? If the dyno has adequate cooling fans, air temps should have fallen very quickly once it was on. If it doesnt have adequate cooling fans, you should never have been on it in the first place.

And boost control sounds very erratic. Surely a spike to 32psi then steady at 26psi cannot be deemed normal ?

As for boost reductions as a safety strategy, again you'd need to ask whoever mapped it.

Everyone will apply different things under different conditions. But 60degC+ is certainly not good under any circumstances.
What sort of temp probes were they and what sort of response time do they have ?

But as others have said, why on earth would it ever be idling for 20 mins ? Although IMO it shouldnt pose a real issue if there is adequate airflow on offer.
Not a huge pile different than queuing in the fire up lane at a drag strip where heat soak always happens and you race straight after.

YBJ

iTrader: (3)

I will ask the guys from MSD. Maybe they can give some comment to this.

I have added the graph.

stevieturbo

graph not working.

YBJ

iTrader: (3)

I hope it does now.

pee vee

says the intake temps were 22 deg on that graph... but if they were really 60deg, then there is a big difference there, so they cant of had the probe in the right place to get the actual temp ??

YBJ

iTrader: (3)

That is the ambient temp not temp measured after intercooler.

pee vee

ahh i see. well if you were seeing charge temps of 60+ then im certain that one of MSDs maps would of started to adjust the ignition before it got there.

stevieturbo

Something is definitely throwing a wobbler on the high boost graph.

Are there no boost traces or AFR traces ?

Was it a dyno day, or some specific time on the dyno for your car ?

If dyno day, how did other cars perform ?

And was there a cooling fan used ?

mikemcc03

stevieturbo -- And was there a cooling fan used ?

quick net search show this as there dyno.
dont know if the fan is any good as ive never been on a roller..

http://www.proimport.nl/diensten/dyn...ics-450ds-awd/

Turbosystems

iTrader: (5)

the fact that the act compensation ignition table took out may be 4 degrees at 60C is nothing to do with why you lost power
The reason you have lost power is the fact that the act was 60
less fuel would have been injected at this act as you had far less oxygen by volume entering the cylinders
move on from the act ignition retard
22 degrees C would have been the cell temperature not air charge temperature the weber l1 l6 and l8 ecu are speed density
had his act been 23 he probably wouldn't have so little power

Karlos G

iTrader: (4)

Something very very wrong there... 300PS @ 4500rpm then only 160PS @ 6500rpm?!

Turbosystems

iTrader: (5)

what did the RR operator say as he was in the best position to comment

YBJ

iTrader: (3)

The comment was: "your boost is dropping, so that means less power".

Karl

Two issues to consider:

Boost is usually much lower on the RR than the road due to the load not representing that seen in 4th and 5th gear. As such you have to look at what power you have made for the actual boost on the RR. For example if it was only holding 16 psi then 300bhp is a good result.

L1, L6 and L8 (except for pectel strategies) all use boost reduction strategy as ACT's rise rather than gradual ignition retardation. This means if you have passed a critical ACT condition on the RR the amal valve may have completely shut down causing a rapid reduction in boost and the type of power curve you have there.

If it holds it's boost well on the road you have no issues, and is just another problem typical of rolling roads!

YBJ

iTrader: (3)

So what you are saying is looking at this graph and dropping its boost so fast its a safety strategy due to this high charge temp?

The operator tried to get the temp lower for the second run by just rolling it gently, but this didnt do anything. So the second attempt was with a starting temp of 63,5 degrees celsius and I assume this only went up during the test.

cossie4i+

iTrader: (15)

Your intercooler must be very poor or the fan set up on the RR is very poor.

Last time mine was on the rollers it had heat soaked to 45deg but at the end of the run was 22deg

Steve

YBJ

iTrader: (3)

I have a standard 4x4 intercooler with works really well on the road. Temperature stays below 30 degrees celsius under full acceleration.

But I think due to big heatsoak from at least minimal 20 minutes at idle for getting it all on the rollers, strapping it and after that a long calibration period before the real run it went so high. And the fan at the front of the car couldnt get it any lower.

Found a little movie from the run in period:

http://www.youtube.com/watch?v=4WRua...ature=youtu.be

Karl

Watching that video just made me laugh! At best all you are going to achieve is a fooked engine. There is no way the cooling is adequate for any form of power testing!

cossie4i+

iTrader: (15)

Better intercooler required and a RR with a decent fan set up would help

Steve

stevieturbo

Is there something wrong with the dyno operators foot ? Why cant he hold it steady ? Must have a nervous twitch as he keeps revving then stopping, revving then stopping ?


And why is the fan nowhere near the car ? Or is that just to keep onlookers cool ?

A fan with the car like that and bonnet open, should be blowing the bonnet so hard....it wouldnt be safe to have it open.

foreigneRS

is any rolling road fan any good? i haven't seen one yet in a tuning environment that is

things haven't changed since the old days on here have they Karl? bloody rolling roads and their piddly little hair dryers

Karl

Hi mate,

You're quite right nothing has changed. Rolling roads will always be a joke when it comes to giving any meaningfull power figure or being usefull for full load mapping! I personally would rather trust a map I had best guessed whilst sat drinking tea and watching the TV than a car actually mapped on a rolling road!

Rolling roads are great for diagnostic work and basic things like light load mapping, but totally hopeless for any form of flat out mapping!

Oh I forgot to add, Rolling road figures are great pub talk! Sadly the bullsh!t stops when the car hits the tarmac, where times dont lie!!

YBJ

iTrader: (3)

Yes I agree. And the main reason for me to do a rolling road session was to see if the new setup I had bought have a save AFR, steady torque and finally a nice bhp output. In that order.

Reading your comments there should not be anything wrong with my car as it performs very very well at the road with its boost of 26 psi holding till 6000rpm and further. No strange issues of suddenly reducing boost or other strange dips in the power. And a lot stronger than my previous setup that was on msd chip closed loop for greens with a T3.

Karl

Personally I'd get yourself a cheap AFR gauge like the aem item discussed on the other thread, and do some flat out runs yourself on the road. That way you can adjust the held boost in 4th and 5th gear to something sensible and make sure your AFR's are high 11's or richer!

Gary F

iTrader: (1)

I'd take it else way mate!

Gary F

iTrader: (1)

Or as Karl says get an AFR gauge sorted.

YBJ

iTrader: (3)

I think for the revs going up and down the operator needed to calibrate the computer for the right values for the car. But that's just a quess.


And there was a huge fan in front of the car about 1.5m x 1.5m. But it didnt blow me away and I was standing next to the car where the big screen is located. So a lack of enough cooling force can be an issue for my intake temp for getting so high and not going down like on the road?

And indeed, just for AFR reading I could have bought a decent gauge, you are right.
But I also wanted to see the other figures and if someting wasn't right hopefully I could get a good hint were to look for.

foreigneRS

a fan can be as big as you like, but the air will take the path of least resistance and just go around the car if it is not correctly ducted from that distance

Karl

And in any case if you can stand up in front of the fan it's absolutely no use whatsoever for replicating full load conditions! You need wind tunnel conditions to get any kind of decent cooling on a rolling road. (Hence why I only recommend engine dyno's and live mapping)

Actually whilst on this topic let me make another comment regarding ACT's. You cannot judge how good an intercooler is from the rolling road. You need to do sustained high speed runs in 4th and 5th gear holding full throttle for at least 10 seconds. Only then can the suitability of an intercooler be judged! (I recall seeing some of the comics doing intercooler tests on the rolling road!! ha ha ha!)

stevieturbo

Last time I was at AET turbos, must be 4 years ago now. Their dyno cell and cooling fan setup was excellent. Best Ive come across anywhere. There would be no issue whatsoever with cooling due to lack of fan there.

Although seems recently there has been changes in ownership/staff, so no idea what the place is like now.

Karl

No, there is no rolling road I know of in a tuning environment that is good enough to replicate accurate top speed conditions. I have had the opertunity to work on a couple of OE car manufacturers wind tunnel rolling roads and thats as good as it gets, but certainly no tuning outfit has anything like that setup!

That's not to say it can't be valuable taking your car to a well setup rolling road, because a good operator can certainly get a good feel for how well the car is mapped, which is much better than having no idea how the car is setup. The biggest problem comes in extreme setups. With the YB engines I am up at over 10,000rpm and boost pressures approaching 3.5 bar (more to come!) and these conditions cannot be simulated accurately on the rolling road. Detonation, heat and specifically EGT's are so critical under top speed conditions, it simply has to be mapped in car to be confident it will last! Remember thats how all OE manufacturers do it, engine dyno for development followed by months and months of live mapping in all conditions all over the world! No OE car manufacturer ever goes near a rolling road for mapping, end of story!

stevieturbo

Certainly when I was there, I would have no concerns about extended high load testing with AET's setup.

Their fan system was very powerful, and well ducted to where it mattered. Better than any Ive seen anywhere in the UK.

I'm not arguing about road mapping, just saying that their setup is very capable.

YBJ

iTrader: (3)

Thanks Karl for your wise words, it gives me answers.
It confirms wat came into my mind as soon as I looked at these high charge temps from my temp gauge and saw the results of the dyno.

I will give the lads of MSD a call and hopefully they can give me some info how the strategy of their chip is working. This all will certainly support to this theory.

pee vee

I am enjoying this new, more outspoken Karl Norris! lol

PS: Karl, have you got any video of what a YB sounds like at 3.5bar and 10,000 rpm!? lol
(or have i just totally misunderstood what you ment lol )