Boost Spikes, Even After The Waste Gate Porting?!

[45T-XR]

^that is actually stated in the HP ford tuning manual!! I havent had an issue yet?

[arronm]

Did MTA port and do the flapper mod?????????????

[Gazza]

Freight Train - traction control can be on or off and the issue is the same.

45T-XR - Freight Train is right, for testing purposes only I bypassed the boost controller and plumbed the turbo directly to the actuator just to eliminate any flaws that might be in the tune (I guess?). I did test the 7lb actuator multiple times actually with various pre load settings. It didn't really make any difference, it still went up to 14-16lb sometimes so I decided to revert to the factory actuator as the pressure is less to open it (was just concerned for my engine - didn't want to blow it!). I'm not sure what software my tuner used to tune my car but I know that he does a lot of Fords... I think my old tuner (the one I was not happy with) used VCM suite, I think. I'm not 100% on that.

Re the porting job. I asked the guy who did it yesterday (who seems to be quite well respected for his knowledge with turbos...so not MTA..) and he said that he bored the hole to 31mm and he "contours around the short radius into the hole". It seems like he does these Ford XR6 port jobs quite often too as he had multiple housings in his garage waiting to be ported when I was there.... he said that this mod generally works up to about 400 wheel kw for 99% of cases and that's my impression too from going through this website/forum with a fine tooth comb. So he said it might be time to go external, but it seems a bit excessive for such low grunt and boost?? I don't know? I also talked to a friend of mine who has owned multiple turbo cars and he says that the internal gates work up to a point but once you introduce some free flowing gear I.e. exhaust and intercooler etc then the internal gates start to show their flaws.... I also want to change the intake on it soon too by putting a U.B.P. intake on and changing the intercooler piping but I think that is only going to exacerbate my issue if I do that so I think I need to solve this first!

[45T-XR]

How much preload was on the stock actuator when you refitted it? Unless it was far to much it shouldnt have had an issue. The details on the port job seem ok for your boost level. Just to give you an idea. I run a 4"dump with into twin 3" exhaust with a larger PTE6466 still internally gated (granted the PTE rear housing is designed for this turbo and the wategate works nicely. The car made 499rwkw with no boost creep/overboost. On actuator pressure only the car runs 17-14psi. Do you have a means to log this vehicle at all. Does atleast one of you have an Xcal and a laptop, the SCT datalogging software is free and you use an Xcal as the interface. Need to log this vehicle and find out if it is actually boost cut that you are getting. Failing that, its back to your tuner unless you can get the tune file to us to have a look at and see what could be the issue.

[aussie1926]

The hose from the turbo to your actuator is not leaking or have a split?

[Gazza]

Thanks 45T-XR. Its very strange as you are running far better mods than I have with far more power so if was going to happen to someone, it should happen to your car. I figure if that mod can work on a car like yours, it should work on mine too??

Re the data logging - yes I have had a go at it and I have a file that I logged at home (am at work now) so I don't have access to the file. It was just a few random parameters that I logged. Will upload later. I did log the waste gate duty cycle and I notice that when I get my 'boost cut' the wastegate duty cycle goes from about .8 (I think) down to 0, then back up to .8 and down to 0 again. I also see that the MAP voltage increases slightly as the duty cycle is reduced. Not sure what that means....

The decrease in duty cycle would be the boost cut right?

aussie1926 - I have cable tied every air line connection so everything is as sealed as I can make it. So the line that comes out of the turbo to the solenoid and then goes to the actuator is cable tied firmly on all ends...

[ratter]

outright power does not have a bearing on the turbo port and believe it or not the port job is more important at lower boost levels than higher boost levels

[45T-XR]

Sounds like Boost cut to me, did you get the same logs results with the ebc solenoid hooked up and bypassed or did you only log one setup? Did you log TP% or anything like aswell. nothing strange there going on?

I think the tuner might have to load the car to replicate the load on the street, or datalog and tune the wastegate duty cycle on the street.

[tichman]

Hey Gazza,

I've been searching for past posts on what I think might be the same issue and found yours to be the closest to what I'm getting the pip with. Any update on what this was being caused by? I'm down in Hawkes Bay and have just had a tune done on similar mods on 03 ute using 36mm flapper on new housing, 42lb injectors, 450x400x75mm cooler, 2.5 inch hot and cold side with cold side going under passengers headlight with factory bov mounted there feeding back behind rad support panel into 3" intake where battery was with K&N in a box, map sensor located on pipe between bov and throttle body, no cat, in tank walbro, atomic springs, turbosmart 12lb actuator and its going to 14-15 psi spiking to 17 even piped straight from the turbo to the actuator, biggest problem though is the surge or boostcut or whatever it is on around 30% throttle accelerating that has it climb to around 12 then drop really abruptly to around 5, then straight back to 12, cut back abruptly to 5 over and over in really quick succession, making a noise each time. Quite often on WOT it just pulls really cleanly to 15 psi spiking to 17 feeling quite good.

It didn't do this boostcut or surge thing whatever it is on the dyno but started once Id left the shop and was giving it a bit on the motorway (this was in Auckland by the way, 4-5 hrs away), rang tuner and went back and he is looking into it and we are thinking maybe pulling the 5 lb spring out of the actuator to drop it to 7 so we can use the factory solenoid to move things back towards 12 ( have a sedan with same mods except for Monza cooler and stock piping, standard in tank pump, and 38mm flapper mod on original housing that makes 290rwkw at 11 psi) which is what I was trying to replicate with the ute but figured with better cooler/piping/intake it would be even more efficient. This car was tuned 3 1/2 years ago and is still going strong by the same tuner as has just done the ute and he has done many many 6ts over the years so we are both somewhat stumped as to whats going on with this surge/boostcut carry on.

If anyone has an insight into whats causing this I'd be very happy to hear it.

[Bomber]

^^^ oh I feel your pain. My surge was largely attributed to a dud bov. Basically, it would bleed boost under lighter inputs. If I continued a progressive feed in no problems - same if I mashed it. Get yourself a 32mm rubber chair leg bung, worm drive clamp and bolt to blank of the vacuum/boost line and by-pass the sucker and road test.