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If there's that much back pressure, the hot side is badly mismatched.
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Dyno trouble.
- Thread starter MetalSpikeRacing
- Start date
If there's that much back pressure, the hot side is badly mismatched.
- Joined
- 19 February 2008
- Messages
- 1,532
Quote:
Originally Posted by StmpoRaceProducts View Post
without doing the math... at 8k on a c30 with a 40r... your looking at 36-40 lbs of pressure being generated... if your aiming at 8-10 lbs... you have 28-32 lbs leaving through your WG...
If there's that much back pressure, the hot side is badly mismatched.
that is the point im trying to make
Originally Posted by StmpoRaceProducts View Post
without doing the math... at 8k on a c30 with a 40r... your looking at 36-40 lbs of pressure being generated... if your aiming at 8-10 lbs... you have 28-32 lbs leaving through your WG...
If there's that much back pressure, the hot side is badly mismatched.
that is the point im trying to make
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Well, seems like nothing can go right for me.
Last night I got the car to the dyno finally, we strap the car down , and Marco at Magnus got to work.
I was most worrie about start up and with AEM little did I know what I had coming.
Marco's work start coming trough, ...
Marco: ya ya ya, there is 20 kits out there and this has never happened... Well it's happening now. Plus the pipes for the wastegate are to small in diameter for this wastegate .
Me: Fack.
I understand that there is all of you guys running this kit with this desing and has had no trouble, I think upgrading my wastegate to a precision unit has brought up the problem stated above...
Marco did all the tuning on my F/IC SOS S/C I just returned from the Dyno myself a few weeks back after intercooling it. He did help troubleshoot some of the issues I had to work on, and then on attempt #4 on the dyno of last season the car was actually running like it was suppose to. Out of the many SOS S/C'd kits out there I ran into a few issues with mine as well I call it the 1% error margin where I seem to get the products in the failure zone right out of the box, and if its going to going wrong it will happen to me.
I know it can be frustrating at times, but just keep plugging away until you get her up and running the way you want to, keep us posted on your dyno results after. Both Marco & Rob have been great guys and always willing to help me out of a jam... to make more jam... lol hope yours is sorted out soon.
Yep, car parts and modifications should say on them: MLMA.
(Murphy's law may apply)
Well, I've Been driving the car around and boost is nice and steady, the exhaust sounds amazing, so does the 40R spooling. Beatiful.
Going back to the dyno on tuesday afternoon.
-MSR
(Murphy's law may apply)
Well, I've Been driving the car around and boost is nice and steady, the exhaust sounds amazing, so does the 40R spooling. Beatiful.
Going back to the dyno on tuesday afternoon.
-MSR
I'm no expert but I've seen plenty of turbo setups on the dyno. & what i can see is that if the exhaust system is pretty efficient ie low back pressure wastegate placement becomes more critical.
I've seen some beautifully made turbo manifolds with wastgate placement opposite to exhaust flow work with "Street"style exhaust systems.
however the same manifold with a Low back pressure system with even the wastgate removed & vented to atmosphere have seen uncontrolable boost.
In my opinion the wastegate needs to be at least 45 degrees of exhaust flow to work properly on a low back pressure system.
I know in my experience of Indycars the wastegates saw direct exhaust flow & the turbo was at 90 degrees of exhaust flow.
Exhaust gases are like water in a storm pipe they'll take the path of least resistance.
I've seen some beautifully made turbo manifolds with wastgate placement opposite to exhaust flow work with "Street"style exhaust systems.
however the same manifold with a Low back pressure system with even the wastgate removed & vented to atmosphere have seen uncontrolable boost.
In my opinion the wastegate needs to be at least 45 degrees of exhaust flow to work properly on a low back pressure system.
I know in my experience of Indycars the wastegates saw direct exhaust flow & the turbo was at 90 degrees of exhaust flow.
Exhaust gases are like water in a storm pipe they'll take the path of least resistance.
Not Making Power!!!!!
Ok guys, so the boost fiasco has been fixed and boost is steady as a rock.
Now, I really need help figuring out what da Fack it's going on, The car was strpped on the dyno lastnight for a good couple hours, and we just made not power!!!
Marco was working away on it, we did first pull at 6psi to get 280whp;( , the he up the boost to 8psi and we got an scarce 312whp. Marco then found out the the timing was "moving" by it self even when he had locked it on the AEM,
We end up doing a couple pulls at 11psi and 24degree of timing and got just around 370whp, pathetic.
I just can't catch a break...
We think the timing was still moving by the end of the night,
I know the angus kit would of be good for around 500whp @11psi , so @9psi I should seen around 420whp...what's going on!!!!
BTW, no boost leaks, boost was consistent and steady, air/fuel was pretty much perfect, don't know what is but something is really wrong .
Question for angus turbo guys, how much timing are you guys running??
Thanks,
-MSR
Ok guys, so the boost fiasco has been fixed and boost is steady as a rock.
Now, I really need help figuring out what da Fack it's going on, The car was strpped on the dyno lastnight for a good couple hours, and we just made not power!!!
Marco was working away on it, we did first pull at 6psi to get 280whp;( , the he up the boost to 8psi and we got an scarce 312whp. Marco then found out the the timing was "moving" by it self even when he had locked it on the AEM,
We end up doing a couple pulls at 11psi and 24degree of timing and got just around 370whp, pathetic.
I just can't catch a break...
We think the timing was still moving by the end of the night,
I know the angus kit would of be good for around 500whp @11psi , so @9psi I should seen around 420whp...what's going on!!!!
BTW, no boost leaks, boost was consistent and steady, air/fuel was pretty much perfect, don't know what is but something is really wrong .
Question for angus turbo guys, how much timing are you guys running??
Thanks,
-MSR
Following your MLMA theory, I know this may sound like a really silly question, but you never know, is vtech being enabled? This actually happened to me where it was a very simple palm to forehead oversight.
make sure that vtec is engaging and that the butterfly's in the intake manifold are opening. 24 degrees timing with 11psi on pump gas on a stock engine is asking for broken pistons this is about 5 degrees more than I would run with this configuration. If the engine is built with low compression you should be ok
on our turbo system with the 4088 turbo on 11psi we see upwards of 520whp. On are dyno a stock 3.0nsx will make right around 260whp. Something is definitely wrong with the setup where is the engine making peak power?
Peak power seems to be coming between 6-7000rpm, I am not sure if the V-tech was anable, I will check that my self when I get home, anyone care to tell me how to do this on the AEM I am not tunning savvy.
The butterflies I beleave I have unable/open them by unplugging the #3 vacuum line, and capping the actual rubber/vacuum line that leads to the control box.
The part of the line/tubbing that goes in the throttle body, I actually left it open...not capped.
Thank you guys for the help it's really appreciated .
On my car I capped the hard line on the TB and left the rubber hose unplugged....
not sure if it really matters though from searching.....
http://www.nsxprime.com/forums/showthread.php?t=125600&highlight=vacuum+vvis
Wait, cap the hard line that goes to TB and leave the rubber hose hanging uncapped ? Or cap both?
Wait, cap the hard line that goes to TB and leave the rubber hose hanging uncapped ? Or cap both?
O.k done, I am trying to figure out if the Vtec is anble, it is set up to come at 5500 and stay off at untill 5200.
But then on the parameter box for the Vtec, it says it is off when I connect to the EMS, maybe it comes on when it hits 5500??
-MSR
Edit:
Nevermind, Vtec is coming on.
I guess next thing to look at is timing.
I was told by Bob at AEM that the correct way to set the timing on a coil plug on set up, is to make a "bridge" between the coil and a spark plug with a wire, to able to get a good proper reading.
Instead of just getting the signal from the coil wire it self, anyone any input on this?
Where do you guys think those 100whp are?
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I think you are playing with fire. Something is clearly not set up correctly. First off your dyno guy should GRADUALLY bring up RPM's during initial runs and then make very small adjustments to timing and fuel. Once things begin coming together, you slowly adjust boost upwards and make fuel/timing changes. This isn't just (lets add 25 degrees of timing and see what happens) My first FULL pull was at 3psi and made 304hp. That was after a dozen or so 1/2 pulls so we could monitor the motor health much like a Surgeon cuts only after a team of Nurses makes sure the patient is ready and vital signs are steady.
Is your VVIS disconnected? FYI 15 psi could blow your motor in a heartbeat. What are your AFR's?
Is your VVIS disconnected? FYI 15 psi could blow your motor in a heartbeat. What are your AFR's?
I completely understand what your saying on turning boost and timing so hard.
Maybe because he is used to tunning for very high boost applications, but then again he is a well know tuner, so I didn't want to say much to him while he was working.
AFR' are actually pretty good, 11:2 to 11:7
I have the VVIS line (vacuum #3) disconnected and capped, also I did disconnect the TC plug, Rob said that it disables the butterflies too.
This is chaos, I am not even driving the car at the moment.
Maybe because he is used to tunning for very high boost applications, but then again he is a well know tuner, so I didn't want to say much to him while he was working.
AFR' are actually pretty good, 11:2 to 11:7
I have the VVIS line (vacuum #3) disconnected and capped, also I did disconnect the TC plug, Rob said that it disables the butterflies too.
This is chaos, I am not even driving the car at the moment.
Doble post.
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That AEM map i gave you made 370HP @ 6psi with a GT35R (small compressor 57mm) & .63 exhaust.
with less timing than you are running.
Do not use the bridge wire to set timing. Some timing lights do not work accurately with this method. remove the coil connect a spark plug lead & connect the timing light to this lead.
with less timing than you are running.
Do not use the bridge wire to set timing. Some timing lights do not work accurately with this method. remove the coil connect a spark plug lead & connect the timing light to this lead.
Ok I will Reset timing today, what should it be set at?
I have been talking to Beau at AEM, he's has been extremely helpful and he offered to take a look at the log and the map that I am running right now and here are his observations:
"Thanks for sending the log and map. I have to admit, the log looks a bit scary. I’m seeing what looks like a significant amount of knock during some of the pulls and while the engine is under load. From what I can see on the map, it looks like the timing map is very similar to one suitable for an NSX with no boost whatsoever, however it looks like you’re running around 8-9 psi. Normally ignition timing is retarded as boost increases, and also timing is increased with RPM. Your ignition timing during some of the pulls starts very high once full boost is reached (~30* or so) and tapers to ~26* near redline. I am also seeing a considerable amount of knock voltage at all RPMs..
*
What type of fuel was the car tuned on?"
*
Beau Brown
Technical Support
AEM Performance Electronics
Btw the car was tuned on 94oct.
He mentions he can see significant knock, which cant be good.
Maybe a bad knock sensor is screwing up timing?
Car is not going back to Marco for a few days, so now is up to me to find what the issue is..damn it.
-MSR
I'm in my tuning stages as well. I was told that the NSX has a fair amount of knock voltage, even in stock form, and that SC or turbo just increases it. So a lot of it needs to be filtered out.
I'll let some experts chime in though hopefully.
I'll let some experts chime in though hopefully.
I think it is time for a new tuner before you do serious damage to your car.
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