murlo26

iTrader: (9)

If its on a shift like that you can boost spike. You sure your boost gauge is accurate?

If its not mechanical then its simply a tuning issue.

Sean@Iveytune

iTrader: (14)

It's 100% over, I just checked the logs and I want to post it here for all to see.

if you are seeing a spike during shifting that could be due to the car retarding the igntion before shift.

The real test go in 3rd on a deserted road, start at 2000 rpm go flat and hold to 7500 no shift. Watch the boost, you will see no creep.

If the boost is too high coming off the dyno thats a whole other matter which can be taken care of by dropping the boost down in the SW.

Sean

Sean@Iveytune

iTrader: (14)

Please see the log I have posted. If you would like bring it back and we can go on the road together and log etc.


Sean

Sean@Iveytune

iTrader: (14)

Kinda looks like the boost is going down with RPM, pretty normal on these applications.



Sean

sparky

iTrader: (1)

I like the boost log! Flat across the RPM band at 25 PSI. No knock up on top. This is on 93 octane pump right? Are you still on the stock IC?👌

ChrisCarey

iTrader: (38)

I'm at a trade show through Friday, but I would be happy to get on a call early next week if you feel it still have not been resolved.

AkumaMotorsport

Sean(the OP) and I had a very long convo yesterday regrading the car. My main concern is addressing this issue for him asap.

The turbo has an 18PSi actuator and can not run lower that 25 PSI. I understand the log shows a 24PSI run with peaks of 25+/-.05PSI. This is great on the dyno, but not in aggressive street driving. The boost slowly raises above 25PSI after 5500RPM regardless of WGDC values.

The thing we are not seeing is that this log is from a pull on the Dynojet, which is not a load bearing chassis dyno. The car needs to be driven on the street, as Sean Ivey suggested, in order to see what the car is doing at higher boost/RPM combos. The OP has done this and sees 26 - 28PSI at RPM exceeding 5500RPM. Once the car is loaded up, exhaust pulses are pushing beyond the limits of the WG orifice. Basically, this car, with an 18PSI actuator, should be capable of running 18-20 PSI, with no boost spikes. This car can not do that, therefore we need to fix it for him.

When I tune a set up like this, I like to tune a few different boost level before arriving at the final requested pressure. If I am going to shoot for 25 PSI, I will tune 20...22...24...25PSI intervals to be sure the calibration is set up properly at all the necessary break points. Before anyone reads into this, I am NOT commenting on Sean's tune. This is NOT an attempt to question his methodology, I only want to solve this issue for the customer. The timing and fuel curves will be set accordingly... there is no real reason to go into the fuel curve or timing strategy, as we are only concerned with boost at this time.

Someone mentioned a boost spike, and Sean is correct. When timing is retarded at a shift point, this can have an anti-lag type effect and cause a spike. This spike can also be cause by the WGDC tables being set up too aggressively. If you do a dyno pull and the table is set up to have a low WGDC value at peak boost, and then ramp up toward redline, this can produce a smooth boost curve on the dyno, but when you start running it on the street and have different shift points, you can run into over boost issues. ie. on the dyno a WGDC of 50@5500RPM may give you 24PSI because you are into the pull already. On the street, this 50 may be to high because you are shifting into that point and require less duty cycle at that RPM/Load combo.( I hope this make sense to visualize). So there are a few reasons he could be spiking. The key here is the real world driving scenario where he will see constant boost creep as he revs through the pulls beyond 6000RPM.

IMO this appears to be a simple mechanical issue. The orifice(hole) in the exhaust housing can not divert enough gas pressure to alleviate the over boost condition. This turbo can not run 18 PSI as the actuator is designed to do. If you take the boost controller out of the equation, the car can not run the mechanical boost it is designed to do. The tune may be OK at 24PSI, but the fact is the product is designed to run 18PSI and higher, it can not do this. These things can happen. I am not blaming anyone or claiming anyone has bad products or services. We just need to work together to arrive at a solution. I have told Sean(OP) that I will make myself available to him anytime. I suggested a conference call with MAP. I am more that willing to take the car on the road and dyno to get whatever data is needed to get a new housing or turbo to test. We all want to see Sean have a car he can enjoy for years to come with no worries for mechanical reliability.

Again, I hope to have this fully resolved for Sean ASAP. If Sean has time, we will get him down here so we can get some more data and get his all ironed out. We just need to stay focused and we can get this done.

Regards,

John

sparky

iTrader: (1)

It is a fairly simple and straightforward task to determine empirically and thus prove as a practical matter, whether or not boost creep is due to a restrictive bypass port, or the WGA, as stated in your opinion above:

1) disconnect any and all boost control devices such as boost controllers and boost solenoids, etc.

2) disconnect the WGA's rod from thr flapper valve's pivot arm.

3) plug off open ends in the boost/vacuum lines.

4)wire the flapper valve full open.

5) do a WOT run and watch the boost gauge.

EnjoyDriving

iTrader: (29)

Any update on this??