Oem K04 Power Output(Debate)

[ibizacupra]

Not sure if you are disagreeing with me or willy, but I believe we are both saying the same thing?

My reply was to you not wildwilly.

hybrids have (depending on manufacturer) larger compressor wheels and larger turbines or clipped turbines.. so yea, viewed singly, the turbine should ahve less back pressure if it can flow more, BUT, you cannot ignore the compressor is larger, and the nett result is there is more backpressure unless you relieve it somehow (porting things larger etc)

hope this makes sense

 

[Mark300zx]

My reply was to you not wildwilly.

hybrids have (depending on manufacturer) larger compressor wheels and larger turbines or clipped turbines.. so yea, viewed singly, the turbine should ahve less back pressure if it can flow more, BUT, you cannot ignore the compressor is larger, and the nett result is there is more backpressure unless you relieve it somehow (porting things larger etc)

hope this makes sense

Yeah fair point, the larger turbine does help get rid of the back pressure but obviously it is specific to the particular product, does your hybrid have bigger compressor+turbine as well?

As someone involved with these cars at what point do the stock actuator springs become obsolete?

Also wouldn't electronic boost control be more advisable for some of the hybrid guys as they have built in boost limiters and it is a lot more controllable for winter/summer?

 

[ibizacupra]

Yeah fair point, the larger turbine does help get rid of the back pressure but obviously it is specific to the particular product, does your hybrid have bigger compressor+turbine as well?

As someone involved with these cars at what point do the stock actuator springs become obsolete?

Also wouldn't electronic boost control be more advisable for some of the hybrid guys as they have built in boost limiters and it is a lot more controllable for winter/summer?

The "uprated" actuator, is a mis-noma to me... its stiffer, but thats not uprated to me.. but thats just semantics and me

When a stiffer actuator is added, its often because the soft 5psi stock actuator cannot hold shut under full boost... which you can imagine may produce more than 5psi manifold pressure in the exhaust manifold/collector area.. and in this instance the wastegate can be blown open but this, which looses boost.. Excess backpressure is whats goign on, which is a bad thing to have anyhow.. Now a 5psi does'nt need to go very soft to loose its already low shut pressure, so there will be instances where some have gone soft and lost their shutting ability.. this can often be recovered to an extent by adding more preload, but I have only ever seen a 2-3psi max adjustment by doing this.

Going too stiff on n75 boost control will cause a massive boost spike and deviation... muchos bendy rod torque.. scarey stuff. MBC can clamp this spike and tame it tho.
EBC depending on how they control *should* also be able to do this when setup appropriately.

the CR turbo k04's use larger compressor and turbine. turbo dynamics use the same compressor but choose to clip the turbine.. I would imagine a CR turbine "clipped" will be even more top end potential with the small sacrifice of spool... but hybrid to stock k04 they dont seem to spool lany slower at all, just more everywhere and hold on longer up the revs

regards
bill

 

[Mark300zx]

Thanks, is there any particular reason the N75 becomes unreliable when tampered with, I would have thought electronic control would have greater performance and reliability than a MBC?

 

[ibizacupra]

Thanks, is there any particular reason the N75 becomes unreliable when tampered with, I would have thought electronic control would have greater performance and reliability than a MBC?

N75 tampered with? I dont understand sorry.

N75 is sized for a k04 turbo on 5psi actuator, as is the PID control from the ecu to achieve the requested boost... The spool charcteristics of the hybrids and k04's with stiffer actuators changes the control parameters, which is why so often (but not always when mapped to accomodate it - very difficult at times!) the end result is an overshoot in boost, and poor recovery by the ecu to pull it back..

log your car and watch the n75 duty cycle % leap to 95% on block 118 as soon as you are accelerating.. Inherantly the ecu's askign for as quick a spool as possible (95% duty cycle is wastegate shut) until it see's the map sensor actual boost get to the request 9and shoots past) and N75 just cannot react quick enough with the ecu in control to prevent the overshoot and subsequent boost/torque spike.

EBC's which run slower update terms in their PID, or can run fixed duty cycles dependant on rpms/throttle position etc, can make this delivery "better". Mapping the N75 can also do this, but its not always simple when the actuator is just to stiff to start with.

phew..

 

[EL]

Hey guys interesting read here. I have been debating whether to change my rods and have a quick question.

I am trying to understand whether by changing the OEM actuator to the forge one on a standard LCR set up would see any benefit? My plan is to install a MBC to level out the boost spikes and have a custom map put on. However is it worth changing the rods now (as I am getting the belt and water pump done soon) or can I get away with keeping standard rods and making sure the map which is put on doesn't put too much stress on the rods?

 

[Mark300zx]

I think what Bill was saying is that it is only worth uprating to a forge actuator if the stock one has gone soft, which is you look at your log or dyno should be detectable?

 

[DaNnY_LaD]

Reviveing an old thread.

Well with all my mods on the revo stage 2 map i made 270bhp & 277ft-lb & 210g/s @ 20psi the reason for the low torque was the ''Uprated Actactor'' being too stiff...Seems the Yellow Spring is far too stiff even though set to 24psi Peak in 4th after the RR.it woundnt keep the Gate shut ''unless'' I wanted to run stupid boost on a OEM K04...Boomtasic....

So with me faffing around i thought id refit the Green 10psi spring which has made things Mucho better...Along with it spooling slight earlier it holds boost better topend.. Also with the Green spring in side it didnt spike no were near as bad unlike the Yellow One so Could it be a Compormised as a upgrade on a Non Standard bottom end...


Im going to have it RR'd on saturday to show the results on the green spring & 3'' tip...Its Rather Rapid at the moment though....

Edit:

I know I don't have any proof of logs,dyno data of the performance of a Actuator but as i drive it everyday it defo feels alot better but thats my opioin and im happy with the ££ ive spent on it...

 

[rsmith]

Hi Danny,

270bhp is probably a true figure for stage 2 on an honest dyno, I really had trouble pushing mine past 270bhp back when i had a stage 2.It would be great to see a dyno read out so we can see how the 270lbft is distributed across the rpm range.

 

[EL]

If be happy with 270bhp which holds power through the rev range instead of just spiking and dropping off as in the real world that won't do anything

 

[Joeb]

ive given up on BHP figures, whats the point when its only high up in the revs


its more torque for me

 

[brad1]

My oem actuator spring has gone soft, Nick from R T.e.c.h diagnosed this when doing logs on my car when adjusting the revo settings on the rollers. He has advised a forge actuator but if i can get a oem actuator, that would be fine. Im gonig to get a forge one and go from there

 

[DaNnY_LaD]

I'd recommend the Green spring mate that's stiff than OEM at 6psi and the Green on is 10psi

 

[h7 cya]

My oem actuator spring has gone soft, Nick from R T.e.c.h diagnosed this when doing logs on my car when adjusting the revo settings on the rollers. He has advised a forge actuator but if i can get a oem actuator, that would be fine. Im gonig to get a forge one and go from there

Which Revo settings are you running Brad?

 

[brad1]

Which Revo settings are you running Brad?

I cant remember mate, think its on boost 8 and the timing is on one of the lowest settings i believe, no matter how hard Nick tried the car wasnt pulling any CF's i believe when advancing the timing

 

[DaNnY_LaD]

Sorry for the late reply Brad...

My Settings are Boost 9, Timing 7, Fuel 8 on 99 Tesco Ron.... This Was the Currently Graph when my Actuator Wasnt set all....I still made The Bhp but lost the torque due to the wastegate being blown open..

Now Its all fixed and set up how it should be Im looking forward to getting it back on the RR In the next few weeks....

 

[jimbob99]

well regardless of what all the paperwork says danny, ive seen that thing set off down the slip lane and it left mine for DEAD

 

[DaNnY_LaD]

Heres the updated RR off my car all setup correctly

288 Bhp & 337ft-lb gonna order a EBC or MBC later