Hks2835 Tune

[75coupe]

I did give the tuner a manual turbotech boost control bleed valve, and he tried that and it made boost control worse...

I'll play with wastegate preload and boost control gain on the PFC and see what happens....

[Harey]

Boost control as others have mentioned is shocking...

Ditch the Power FC boost control kit as it is junk, either install a Turbotech bleed valve for $35 which will work very well or fork out for a Blitz Dual solenoid (spec r or IDIII) so you can have multiple boost settings

I think shocking is a slight exaggeration. Yes it could be improved but take a look at joeyjoeys boost curve with the same turbo, it hits boost faster but still drops off about 2psi. It could be the turbo and engine combination that means it cant hold 20psi till redline. Turbos that have a strong midrange can often do this. A lot of the 3076s and hypergear turbos seem to exhibit this behaviour. I think someone said its to do with the amount of air flowing through the wastegate pushing the wastegate open (overcoming the actuator spring). In this case I dont think a boost controller can help you.

But by all means I would be winding the gain up to get it as close to joeyjoeys result as possible.

[Harey]

I did give the tuner a manual turbotech boost control bleed valve, and he tried that and it made boost control worse...

Interesting, I could understand that it did not improve the boost control as the wastegate was overcoming the actuator spring but I cant understand how it could make the boost control worse?? I dont think it was setup correctly.

[DVS JEZ]

people say the same bad things about Vi-pec boost control, its just a DC adjustment and when setup correctly will nearly as good as any

[wolverine]

The main issue with Turbotech (a few years ago) that I have seen is that as boost rises small turns can lead to large increases in boost.

For low levels of boost they seemed to be great value but closer to 18psi it was getting a bit erratic so perhaps the tuner had a similar issue??

[Dale FZ1]

needs a stronger actuator. I would go for a 24psi atmospheric pressure rated actuator, whichs should hold 18psi without boost controller. Garrett part: 446131-23

I'm running the std HKS actuator and the PowerFC boost control kit...

Interesting, I could understand that it did not improve the boost control as the wastegate was overcoming the actuator spring

people say the same bad things about Vi-pec boost control, its just a DC adjustment and when setup correctly will nearly as good as any

I'll share a little recent/ongoing boost control experience with GT3037 Pro S on 30DET.

Started with 12psi actuator running straight feed to the actuator, no BC. Definite problem with boost slowly building then running away to 19psi and tapering to 16psi; not readily fixed or changed with preload.

Changed to a 18psi actuator, trialed with straight feed again. Slower boost build to peak 19psi, again tapering to 16psi. Obvious that actuator spring strength affected the rate of build, and was generally more effective.

Activated and tuned the Vipec BC map. Found that it is very sensitive to adjustments, and duty cycles were effectively addressing the characteristics observed when not running any BC. ie. high DC to promote fast boost rise, quickly tapering to allow the actuator to do its thing and limit boost to the observed peak. Then finally start to ramp DC back up so that boost didn't fall again beyond 6000rpm. And come to the conclusion that the turbine is probably getting to its flow capacity and starting to struggle a bit.

I did find that the boost "curve" was a bit wavy and didn't look super smooth with up to 1.25psi variation through the range. Not my ideal but it works ok.

Comment to OP: make sure you use an actuator not far removed from your target boost. Light-pressure actuator probably won't cut it if you want to run some bigger boost levels. Get the preload set right. An extra turn or two on the rod will make a difference. Be prepared to play with EBC settings to get it "right" or at least to an acceptable degree of control.

Good luck and don't worry too much about the power number. Look at the shape of your torque curve.

[75coupe]

thanks for the comments Dale, I'll play with some small changes and if they dont get me the on boost response Im wanting I'll look at another actuator...

Its all about response for me, top end power is good, but response is better...

[DaveO74]

This will feel like an absolute weapon on the street I'm sure, more so once your boost issue is sorted. Congrats mate, I think you have helped me make up my mind on this turbo, to my laymans eyes looks much better than what the 3071 would deliver.

Did you get the whole pro s kit or just the turbo?

Sorry for the little hijack:)

[75coupe]

I was able to find the turbo brand new with gaskets and studs for sale heaps cheap (like cheaper than a 3071 would be) in the for sale section...

Hopefully I can get it to achieve full boost by 3500rpm and bring the whole curve on earlier... maybe play with the VVT as well..

[GTScotT]

thanks for the comments Dale, I'll play with some small changes and if they dont get me the on boost response Im wanting I'll look at another actuator...

Its all about response for me, top end power is good, but response is better...

Can I note, you are making power in the following intervals:

3-3200 100kw~

4000 200kw~

46-5200 240kw~

6-7300 280+

Now may I ask, where would you like to IMPROVE YOUR RESPONSE?

Response is how quickly the car makes power, not how quickly it comes on boost. Torque wins races, certainly not PSI@xRPM. While boost response may be a set variable to how a setup may perform, it is not the key indicator.

Consider when plotting the compressor map of a turbo, variables taken into consideration is RPM/boost/engine VE/engine size. Alter the engine VE and for the same flow you will be pushing LESS boost than before. Same FLOW = same POWER.

You are achieving a result that some argue is not possible from a turbo this size, are you certain that you need your boost to come on earlier? And are you certain that having it come on sooner will not make for a less desirable outcome overall?

I remember I had an evo 4 with the most epic response id ever seen, truth of the matter was it would hit target boost at something along the lines of 5000RPM on the stock turbo. Infact I found that fairly normal for an evo with my mods. Friends had similar cars with more restrictive exhausts and saw boost on notably earlier, but also were NOT as fast when it came to torque or response.

Key point, I believe this turbo wishes to run at roughly 18 psi on this motor - not more. You are also achieving this by 4000RPM, for a 6 cylinder this to me sounds like epic delivery.

How does the car actually Drive now? Please elaborate.

[75coupe]

well I must admit Im yet to drive it in the dry, so I couldnt actually get past 4500rpm today... (maybe that is saying something) but as soon as its dry I'll take on a favourite road and see what happens...

I guess it'll become a traction game eventually...

I want instant power basically, so I can control the car with my foot, not just foot down waiting for power to hit...

[wolverine]

With better boost control there is more to be had earlier on the ramp up to 3600rpm. It is making the numbers otherwise.

Does it matter? This is a SAU so squeaking out every last bit of performance (especially early/midrange) is serious business especially when someone else is paying the bills.

[GTScotT]

Does it matter? This is a SAU so squeaking out every last bit of performance (especially early/midrange) is serious business especially when someone else is paying the bills.

LOL, it doesnt matter no.. I just am not confident it has much more to give.

I base a great deal on feel when driving, one of these is RPM points of a motor. While a good 2L4 has something to show for 3500RPM, those are not necessarily big revs for a I6. I would say I am of the opinion that a 6 makes peak torque on a good street setup roughly 1000RPM later in the rev range than a 4 (say SR20 or 4G63 vs RB). This doesnt translate to lag in my opinion, I think these are simply the delivery characteristics of the motor.

Personally results in question only further concrete the fact that I WANT one of those turbos.

[R31Nismoid]

I think shocking is a slight exaggeration. Yes it could be improved but take a look at joeyjoeys boost curve with the same turbo, it hits boost faster but still drops off about 2psi. It could be the turbo and engine combination that means it cant hold 20psi till redline. Turbos that have a strong midrange can often do this. A lot of the 3076s and hypergear turbos seem to exhibit this behaviour. I think someone said its to do with the amount of air flowing through the wastegate pushing the wastegate open (overcoming the actuator spring). In this case I dont think a boost controller can help you.

But by all means I would be winding the gain up to get it as close to joeyjoeys result as possible.

3076's do not have that issue at all. They will smash 20-25psi @ 8,000rpm no problem.

My GT3040 had 24psi until 8,000rpm without a sign of abating. It was external gate (.82), but a proper IW housing on the 3076 and you wont have these problems.

Its just a case of the compressor nosing over really IMO.

The next step is the 3037ProS in the HKS speak which is virtually the same as the 3076 and they never had any issues either and would make 300-330rwkw on PULP on a 2.5ltr.

Dale's example is a bit of a odd one, i wouldn't have thought it would drop that hard at all as the rear certainly isnt running out as they are a .78 IIRC either way they aint running out of exhaust flow.

[joeyjoejoejuniorshabadoo]

Can you check your EX cam gear setting?

totally forgot man.... i'm running a greddy ex cam gear aswell

Its the same format as joeyjoeys dyno so 'Dyno Dynamics'

one is DD the other (finished is a dynapack, set to give the same results as DD)

Can I note, you are making power in the following intervals:

Now may I ask, where would you like to IMPROVE YOUR RESPONSE?

we played with my setup HEAPS (well in excess of 100 passes) and found that it likes as much gain as possible to spike to between 20 and 21 psi to get things moving, and then to hold as close to 18psi as possible.

there is definately room for a little more fun in that setup.... but not that much more... at this point my number 1 concern would be safety

[GTScotT]

there is definately room for a little more fun in that setup.... but not that much more... at this point my number 1 concern would be safety

Fair call, up to the OP I suppose.

[joeyjoejoejuniorshabadoo]

exactly... although the number 1 fun thing in driving my car is having the full 20psi by 3400 rpm

it's the sole reason that i went for this turbo and not the 3037 kit

[GTScotT]

Well now you can sell it to me for my JZ lol

I had the 3037 pro S on my RB25 for a very short stint at 10psi. It felt like it would have been epic, although there is something that the back cut wheel and 71mm compressor just do in my pants.. Cannot deny!

[Revspeed]

simple.... just needs more boost...

i run 20psi through mine which trails of to 18 by redline and i make 285rwkw

what boost controller are you running? and which actuator?

how close is this dynopack to the dynodyanmic?

[89CAL]

I think the main difference between the pro s and the KAI is the inlet and some internal improvements. I will take some photos soon. Working 12 hour days at the moment so dont get alot of time to do things lol