First dyno run today!

olliecast

olliecast

Active Member
First dyno run today! UPDATED!! 05/12/07

Hi everybody, had my first dyno run on my r today.
was just to get the timing and fuelling checked but got a plot at the same time.
mods are k&N, MBC (set at 1 bar max), Walbro, Decat, Magnex turbo back, think thats abou tit engine wise.

made 279.7 bhp and 264 torques!
Chap at noble motorsport (excellent service!) said the fuelling was fine, along with the power curve. Only thing he said as an observation was the boost tailing off.

plot below.
sorry about the boost line at the bottom, right click, save as then you can zoom in to see it!!
I`m fairly chuffed, what you guys think?

 
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antgtir

antgtir

New Member
TMIC or FMIC?

Looks a nice profile, at least its not boost spiking lol.

Have you any other engine management device installed?

Ant.
 
olliecast

olliecast

Active Member
its a tmic still mate, haven`t took the plunge yet. by mbc i mean a manual boost controller. its the ball bearing type though that uses spring pressure to regulate the flow of air.

i`m wondering whether the high revs is causing the sping to preload more therefore bleeding off boost pressure.
if the boost didn`t bleed, the power would be nigh on 290/300.
got to admit though, i`m loving the torque and power curve
 
stumo

stumo

Active Member
a stock R with a dawes device running 1 bar should hold the boost right up to the redline.
 
P

pulsarboby

Guest
yeah you are losing a lot of boost pressure there ollie!
i reckon that either the boost controller you have is bleeding the boost. or you could possibly have a few cracks around wastegate in exhaust housing.
if the boost was running around the 1 bar mark right through, you would have been making around 300 mark.
 
olliecast

olliecast

Active Member
pulsarboby said:
yeah you are losing a lot of boost pressure there ollie!
i reckon that either the boost controller you have is bleeding the boost. or you could possibly have a few cracks around wastegate in exhaust housing.
if the boost was running around the 1 bar mark right through, you would have been making around 300 mark.
Click to expand...
rubbish!! lol. is there a way of checking for cracking around the wastegate housing with the turbo in situe? if not then do you think its worth biting the bullet and just getting a proper electronic controller?

is it also worth checking around my current boost pipes for leaks?
 
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pulsarboby

Guest
can be done with pressure tester but you really would need to remove elbow to check it out properly!
eliminate all possible cooler leaks first and check boost pipe connections.
but i still reckon the housings cracked around wastegate;-)

they seem to hold around .7 bar no problem, but soon as you up the boost level thats when this becomes more apparent, could possibly be the controller but i doubt it.

another way to try it is disconnect the vacuum from actuator, then see what it boosts to and if it holds boost (better to do this with someone else in car keeping an eye on the gauge) once you reach around 1.2 try and hold it steady, and see if boost level drops off!
 
M

MarkTurbo

Well-Known Member
pulsarboby said:
i still reckon the housings cracked around wastegate;-)
Click to expand...
Both my last 2 turbo's have been cracked around the wastegate and they still hit 1.5 bar no problem ;-)
 
C

CanadianR

Member
Don't use that device from ebay.

They are cheap and work about as well as they are worth.

You can make your own for less than that cost.

From what I've heard, the AVC-R seems to be a good buy.
 
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pulsarboby

Guest
MarkTurbo said:
Both my last 2 turbo's have been cracked around the wastegate and they still hit 1.5 bar no problem ;-)
Click to expand...
it really does depend on how badly they are cracked mark!!! ive seen some with 0.5mm cracks in that wont even hold standard boost.
yet others have just hairline cracks that dont seem to cause a prob. you cant judge all turbos just by your one, every one is different.
to sum it up, only way your gonna find out is by testing it to see what the prob is.

but as matey above says 'i would have to take a very close look at the cheapie boost controller thats been fitted,
 
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youngsyp

Active Member
I reckon it's either a cracked turbo housing or, a weak actuator. From my experience of the relief valves, that you're using for boost control, they hold boost very well. Of course, the spring it that could be tired too though !

Not sure how you would test any of these things though, without replacing parts ?!
 
G

GTi-R23

New Member
I'd still invest in an electronic boost control device, it's a worthwhile investment and can be adjusted in car, so it has many benefits other than just a potential cure to the boost tailing off.
 
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youngsyp

Active Member
GTi-R23 said:
I'd still invest in an electronic boost control device, it's a worthwhile investment and can be adjusted in car, so it has many benefits other than just a potential cure to the boost tailing off.
Click to expand...
Despite what I said above, I would totally agree with this.

Have a look for my dyno graph on here, you'll see the boost 'curve' is ruler flat once the turbo has spooled up. This was using an AVC-R boost controller.

You can also get the best turbo response possible and tailor the boost curve to rpm's and specific gear if wanted.
 
olliecast

olliecast

Active Member
so say i have got a cracked housing. what are my options? is it going to be a case of getting a second hand turbo housing?

if you look at the dyno run aswell, why, when the boost drops off does it do it in an un-uniform line. The boost is held up to 1 bar, then seems to hold for ~1000rpm and then staggers down to 0.7 bar at 6890 rpm? could it be the ball bearing in the mbc being "moved around" by the increased flow at higher revs?
 
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youngsyp

Active Member
olliecast said:
so say i have got a cracked housing. what are my options? is it going to be a case of getting a second hand turbo housing?

if you look at the dyno run aswell, why, when the boost drops off does it do it in an un-uniform line. The boost is held up to 1 bar, then seems to hold for ~1000rpm and then staggers down to 0.7 bar at 6890 rpm? could it be the ball bearing in the mbc being "moved around" by the increased flow at higher revs?
Click to expand...
Looking at that boost curve again, I'd rule out the cracked turbo housing simply for the fact that it does reach the 1 bar level, holds it then drops off.

I think it's either your boost controller or the actuator.

Take the boost controller apart and clean it. Before you reassemble it, stretch the spring slightly, so that it's tension on the ball bearing will be higher. Then reset it and see how it holds the boost level. You'll need a decent, easy to read boost gauge to do that and, someone to watch it as you drive. I guess you have the gauge though, if you set the MBC up ?!

If you don't see any difference, I'd check the actuator next...
 
olliecast

olliecast

Active Member
rite, so first i`ll try stretching the spring slightly (would this have the same effect though as turning in the knob? i.e preloading the ball bearing more?). i`ll check all hose connections and i might even put a bit of sealent around them to seal. anybody reccomend something decent to use?

so say this doesn`t work and it still drops off. is checking the actuator a massive job?

the mbc i`m using is this: http://boostvalve.com/pricelist.html

another thing is that the two metal pipes under the top mount aren`t connected to anything, could this be causing a leak?
 
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Odin

Guest
I've moved this now because it's turned into a problem solving thread really.





Rob
 
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