Almost done

[falcon]

no its all custom now..I have driven the car in the past..before aa little malfunction and all the surge was eliminated. The surging is a fairly new occurance but was fixed in past tunes.

are you talking about actual surging... or turbo shuffle.

if it's the latter... time to get used to it as chances are it will always be there. I know from experience.

[Eber]

Its a little bit of shuffle and a little bit of surge... No wait tons of shuffle!!! I have tuned it out before so I know it is possible.. teh fact the Cas broke in half didnt help matters at all.. hahaha.. But we are bringing the car back to dyno later this week and a street tune to get rid of all the shuffle below 4,000. The AFR's were finr but most of the combustion was occuring way to late to TDC so needless to say my eyes were burning at the end of the day. Once the cam gears are set I think when the internal combustion happens internally there will be a serious difference in the power! I havent even tapped 1/2 the power these turbos are capable of so i see larger #'s for sure but I dont want to say too much. There are a lot of variables in my setup. I will show a full build thread at a later date so all is known.

[mwracing]

good luck with everything!!

[Eber]

Well A little update here... The car was back at dyno today and there were many cam adjustments made since the last time. It did wonders for the surge and drivability, but did little to nothing for the power levels. Reason being is that at higher boost levels the two turbos are working against each other. Therefore I am unable to make higher power, or add boost at all past low levels. i cant even get them into efficiency maps. By looking at the dyno graphs the tuners are begining to wonder about the true nature of my turbo's due to the fact that the surge points dont match that of the compressor maps listed on garretts web site. I have assured them that they are what I assume they are but they are wondering about the strange flux's in the pulls. Hopefully more will be figured out at a later date and I will be able to post some more information.

[Eber]

Well it seems as though we have discoved the problem to my car not running since we have put it back together...DEFECTIVE TURBO!!!!!!!!. Thats right people you heard me. It seems as though one of the turbos has a defective actuator which is preventing from sealing properly. Upon closer inspection of the wastegates we have found that one of them is 2mm farther out than the other...So being both turbos are the same both are fighting at unequal pressures unable to retain power, boost, or let my car run PERIOD!!!!. Nedless to say I am very pissed off right now and in desperate need of a beer. This is because like most others on this forum who have decided to build one of these things.. I'm broke!!!! It looks like the insurance is comming off and the shot gun is comming out of the closet! Run and hide!!!!!! We are going to take apart the exhaust side in the next couple days to see why the faliure occured and why I didnt notice it upon putting them on the car. Im guessing because we only ran 12psi through them to check the wastegates were working. 15psi is where they are slipping. This is very dissapointing that I did not hear about this problem earlier and even more dissapointing that I have a $30,000 paper weight.:hit_head:

[MikeM@Ztune]

Sorry to be the bearer of such bad news tonight bud. Talk about the never ending story hey. As much as I love your car, she can be a real bitch sometimes! It appears that this problem crept in (or at least got significantly worse) today right from the start of the tuning.

As we've tuned this car to 1.2bar with no shuffle before, we knew something was off when the car started shuffling at 1bar, even after the adjustment to the cam gears got rid of the shuffle down lown. There is no way they should shuffle that bad once getting into their efficiency zone, which told us right away that something was majorly out of balance between the two.

Upon inspection, we noticed that one wastegate arm shaft sticks out of the turbo 4mm, and the other sticks out about 8mm. Generally they don't even stick out as far as 4mm. Since there is only maybe 2mm of overlap of the shutter over the wastegate port, at least the back one is definately going to be leaking boost out the wastegate all the time. That explains the lag, the lack of boost, and the shuffle getting worse at higher boost as the back turbo will be spinning slower and making less boost than the front one.

Nonetheless, we will get the turbos out so that we can repair them and get her back in business. What a crummy problem to have at this point.

[falcon]

That sucks.. it seems to be one thing after another. Such is the story with Skylines. Hopefully it will be up and running soon.

[Daryl @ RightDrive]

Sorry to hear you've had some more bad luck Eber. One way to look at it is that when the car is finally running perfectly, it will be that much sweeter!!
I'll cross my fingers that all goes well for you.

[Eber]

The amount of $$ time and effort put into this car is crazy! I'm not just talking about myself... The staff at Z-tune including Andrew and Jerie specifically have donated parts to my build because they believed in what I was doing so much.. This just goes to show me the lengths that these people will go to to finish something for me ( a customer, and a friend). I just wish it went a little better because as I have said before I may have had the resources in the past I am now down and out do to the market place and have found better outlets to spend my cash. If it turns out the turbos need significant work i will be going single and looking for blood. It was a very unfortunate turn of events to find out I was on the bum end of a deal but it all happens for a reason. I will update you all about my big block T/A that does wheelies

[JD74]

If it turns out the turbos need significant work i will be going single and looking for blood. It was a very unfortunate turn of events to find out I was on the bum end of a deal but it all happens for a reason.

If you don't mind sharing.....

What was the story behind the Turbos ? Were they purchased NEW by you ? or were they a used purchase from another member ?

Again, I don't wanna rub salt int he wound, just giving you an avenue to vent

Hopefully your luck will get better.
Allan

[DeviantRebel442]

The amount of $$ time and effort put into this car is crazy! I'm not just talking about myself... The staff at Z-tune including Andrew and Jerie specifically have donated parts to my build because they believed in what I was doing so much.. This just goes to show me the lengths that these people will go to to finish something for me ( a customer, and a friend). I just wish it went a little better because as I have said before I may have had the resources in the past I am now down and out do to the market place and have found better outlets to spend my cash. If it turns out the turbos need significant work i will be going single and looking for blood. It was a very unfortunate turn of events to find out I was on the bum end of a deal but it all happens for a reason. I will update you all about my big block T/A that does wheelies

oooo..big nasty turbo and a big block...sounds like an evil drag build how much longer do you think it will take...on the road in 09

[Eber]

I dont want to stipulate the failure yet as the turbo's have not been removed from the car. They were not new and were purchased through a member on this forum.. However all that being said its hard to lay blame as of yet but once the turbos are off and apart it will be easy to see the results of what happened and if they were passed onto me to deal with

[falcon]

Could just be a problem with your wastegates not being properly sync'd. Hopefully that's all it is. It would explain the shuffle...



If they are infact pooched, why not consider 2860's -5 or -10? The -10's would be very similar to the RS's and would bolt right up to your current setup.

[MikeM@Ztune]

Could just be a problem with your wastegates not being properly sync'd. Hopefully that's all it is. It would explain the shuffle...

If they are infact pooched, why not consider 2860's -5 or -10? The -10's would be very similar to the RS's and would bolt right up to your current setup.

The first thing we do before installing any twin turbo kit is pressure balance the wastegate actuators using compressed air and a dial indicator. On cars planning to run high boost, we set the actuator's base pressure to the highest pressure that both actuators will run. That helps improve spool-up, reduces shuffle, and makes less work for the boost controller, which usually means less spiking and high peak boost. Unless one turbo has damaged wheels, they should put out pretty much the same pressure, and not shuffle much.

The wastegate actuators were re-checked yesterday, and are opening in sync. We also confirmed that the shuffle actually starts before they even start to open, which again points to another cause of a pressure differential between the two turbos.

It shouldn't be a big deal to repair the turbos, but they will have to come out so that we can confirm that is in fact the problem and not just a manufacturing discrepancy. The turbo wheels, bearings and oil seals seem to be in great shape from what we can see and feel on the car. So far it appears that just the wastegate arm needs to be repaired, which won't be too difficult once they are out.

[Zulu]

One thing after another... tough luck.... some time and more money and you will eventually have a good running car. It's just the time and money aspect that suck. Such is life... Hope things start going smoother for you.