Jump to content
SAU Community

Recommended Posts

With a Electronic Boost control can you alter boost pressure at different rpms. Im getting 17psi at 4500rpm and then it drops off too 12psi and peak revs. This is using a HKS actuator and no bleed valve so its not the actuator spring. So i thought with a EBC could i dial in more boost pressure at say 6000rpm.

Can i do this?

  • Replies 46
  • Created
  • Last Reply

Top Posters In This Topic

Some EBC's are not intelligent.

Some operate in a closed loop mode that monitors boost and adjusts the duty cycle to suit. The cheaper EBC's tend to have a fixed duty cycle which is why you get boost dropping at higher rpm's.

I used to own a Blitz SBC-ID EBC that had a manual function and auto function.

The manual function was like the regular ebc where you set it to a duty cycle.. Say 43. then you set the gain which controls how fast boost reaches that duty cycle peak if that makes sense. It would make 15psi then tapper off to 12.5psi by 7000rpm.

Then there was the auto function that would require you to dial in the boost you want (say 15psi) it would then slowly learn the boost curve and adjust the duty cycle to suit. This would require multiple 7000rpm runs.

Once learnt it knows that it has to reduce the duty cycle in order to hold that 15psi a certian RPM. It would then hold 15psi to redline.

Wait until you get the PowerFC & get the boost controller to suit that. :mad:

The PowerFC boost controller is essentially the same as the AVCR which is a very good boost controller. Some do not like the AVCR due to its complexity and thoughts that a bigger solanoid is better. Which is untrue. :mad:

EDIT: Stock turbo or not.. It has nothing to do with it. A good EBC will hold boost. i.e the rb20t turbo was able to push 16psi at 7000rpm on the rb20det when with a crappy bleeder it would tapper off to 12.5psi. You need an intelligent EBC. AVCR, Blitz SBC-id or the Greedy E0-1 (Expensive) I think it is.

How good of a boost controller do you consider something like a GReddy Profec B-Spec II, or even a Spec-S?

Some EBC's are not intelligent.

 

Some operate in a closed loop mode that monitors boost and adjusts the duty cycle to suit. The cheaper EBC's tend to have a fixed duty cycle which is why you get boost dropping at higher rpm's.

 

 I used to own a Blitz SBC-ID EBC that had a manual function and auto function.

The manual function was like the regular ebc where you set it to a duty cycle.. Say 43. then you set the gain which controls how fast boost reaches that duty cycle peak if that makes sense. It would make 15psi then tapper off to 12.5psi by 7000rpm.

 

Then there was the auto function that would require you to dial in the boost you want (say 15psi) it would then slowly learn the boost curve and adjust the duty cycle to suit. This would require multiple 7000rpm runs.

Once learnt it knows that it has to reduce the duty cycle in order to hold that 15psi a certian RPM. It would then hold 15psi to redline.

 

 Wait until you get the PowerFC & get the boost controller to suit that. :cheers:

The PowerFC boost controller is essentially the same as the AVCR which is a very good boost controller. Some do not like the AVCR due to its complexity and thoughts that a bigger solanoid is better. Which is untrue. ;)

 

EDIT: Stock turbo or not.. It has nothing to do with it. A good EBC will hold boost. i.e the rb20t turbo was able to push 16psi at 7000rpm on the rb20det when with a crappy bleeder it would tapper off to 12.5psi. You need an intelligent EBC. AVCR, Blitz SBC-id or the Greedy E0-1 (Expensive) I think it is.

AVCR lets you do everything. :cheers:

fuzzy logic, rpm & gear based boost. everything.

GReddy Profec B-Spec II, or even a Spec-S...

I don't know I would have to read up if it has a boost curve learning mode.

If you simply dial in a number say 42 or 45 that has no correlation to the boost figure

its self then it is based on a percentage of maximum boost hence duty cycle.

That is when you will run in to trouble as you cannot get the boost controller to increase or reduce the duty cycle when needed to hold a certian boost.

you will never be able to sustain 17psi throughout the entire on-boost rev range with a 2530 on an rb25. 2 different tuners in here in SA explained from their experience that apparently there is too much exhaust flow from the rb25 at the top end, where the compressor is "spun out of its efficiency" and starts to "chop" the intake air rather than compress it. we were also running 17psi and it always dropped off to 13psi at the top end. in this case, its the turbo, not the EBC that is responsible for the pressure drop. Before we we're told this we had tried 2 different wastegate actuators and 2 reputatable EBC's, all to no avail.

just be happy with the mid-range :D

a HKS EVC 3 or 4 will give the best control out of all of em...

but doesnt offer the fancy stuff like Gears vs Boost... guess thats why they are $150 cheaper. No flashy shit. Just controls boost you ask for

you will never be able to sustain 17psi throughout the entire on-boost rev range with a 2530 on an rb25. 2 different tuners in here in SA explained from their experience that apparently there is too much exhaust flow from the rb25 at the top end, where the compressor is "spun out of its efficiency" and starts to "chop" the intake air rather than compress it. we were also running 17psi and it always dropped off to 13psi at the top end. in this case, its the turbo, not the EBC that is responsible for the pressure drop. Before we we're told this we had tried 2 different wastegate actuators and 2 reputatable EBC's, all to no avail.  

just be happy with the mid-range :D

But i was thinking i could run 17psi in the midrange and when it starts to drop, somehow try and squeeze more boost into it without trying to boost to more than 17 in the middle.

Mate you can up the boost all you want but with a 2530 all ya gunna do is make hot air. And all that will do is bring you that bit closer to detonation.

and you know this because why?

do you know where a 2530's Efficiency range is?

its certainly not at low boost - 10-15psi. HKS turbos are designed to perform better at higher boost... not just "make hot air"

How good of a boost controller do you consider something like a GReddy Profec B-Spec II, or even a Spec-S?

Greddy Profec Spec S is like the old Profec B just with an upgraded solenoid.

Profec B Spec II is a bit of a pain to set up.

Check the link bellow, its bit old but good info.

http://www.sportcompactcarweb.com/tech/020...boostcontrol05/

Mate you can up the boost all you want but with a 2530 all ya gunna do is make hot air. And all that will do is bring you that bit closer to detonation.

no offense, but i dont think youve had much, if any, experience with 2530's on rb25's, because if you had, youd know that you cant "up the boost all you want".

not trying to shit stir here, but im coming from direct experience in collaboration with 2 reputable SA tuners.

Mate you can up the boost all you want but with a 2530 all ya gunna do is make hot air. And all that will do is bring you that bit closer to detonation.

no offense, but i dont think you've had much, if any, experience with 2530's on rb25's, because if you had, youd know that you cant "up the boost all you want". if you have had experience with this setup, i really want to know how you did it, because it was a real pain in the arse :)

i think if it was capable of sustaining 17psi at the top end, after all the tuning and trying different things, we would have been able to make it happen.

now on a rb20, its a different story, smaller engine, less exhaust gasses. my good friend with a 2530 on his r32, making 240rwkw, can sustain up to and over 17psi across the top end.

not trying to shit stir here, but im coming from direct experience in collaboration with 2 SA tuners.

But i was thinking i could run 17psi in the midrange and when it starts to drop, somehow try and squeeze more boost into it without trying to boost to more than 17 in the middle.

it seems to be all due to excessive exhaust gasses. i've always thought that if you enlarged the wastegate, you would be able to bypass more exhaust, slowing down the exhaust turbine and hence bring the compressor back into its efficiency. does that sound right?

i know its not all about the exhaust turbine and housing that matters, but, we have a 2835proS on the 25 now and both the exhaust turbine and its housing is considerably larger than the 2530, and it sustains 17psi rock steady across the top end, and wants to keep going. its so easy to hit the limiter because there is no letting up in the power delivery. after a rebuild it would be interesting to see if we could find the point, if there is one, where boost drops off at the top end with this turbo. but i dont think id like to push it that hard :)

But i was thinking i could run 17psi in the midrange and when it starts to drop, somehow try and squeeze more boost into it without trying to boost to more than 17 in the middle.

it seems to be all due to excessive exhaust gasses. i've always thought that if you enlarged the wastegate, you would be able to bypass more exhaust, slowing down the exhaust turbine and hence bring the compressor back into its efficiency. does that sound right?

it seems to be all due to excessive exhaust gasses. i've always thought that if you enlarged the wastegate, you would be able to bypass more exhaust, slowing down the exhaust turbine and hence bring the compressor back into its efficiency. does that sound right?

The wastegate on a HKS 2530 is bigger than the stock R33 turbo, i guess its still not big enough.

Does the 2535 have a bigger exhaust wheel than the 2530?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • The rain is the best time to push to the edge of the grip limit. Water lubrication reduces the consumption of rubber without reducing the fun. I take pleasure in driving around the outside of numpties in Audis, WRXs, BRZs, etc, because they get all worried in the wet. They warm up faster than the engine oil does.
    • When they're dead cold, and in the wet, they're not very fun. RE003 are alright, they do harden very quickly and turn into literally $50 Pace tyres.
    • Yeah, I thought that Reedy's video was quite good because he compared old and new (as in, well used and quite new) AD09s, with what is generally considered to be the fast Yokohama in this category (ie, sporty road/track tyres) and a tyre that people might be able to use to extend the comparo out into the space of more expensive European tyres, being the Cup 2. No-one would ever agree that the Cup 2 is a poor tyre - many would suggest that it is close to the very top of the category. And, for them all to come out so close to each other, and for the cheaper tyre in the test to do so well against the others, in some cases being even faster, shows that (good, non-linglong) tyres are reaching a plateau in terms of how good they can get, and they're all sitting on that same plateau. Anyway, on the AD08R, AD09, RS4 that I've had on the car in recent years, I've never had a problem in the cold and wet. SA gets down to 0-10°C in winter. Not so often, but it was only 4°C when I got in the car this morning. Once the tyres are warm (ie, after about 2km), you can start to lay into them. I've never aquaplaned or suffered serious off-corner understeer or anything like that in the wet, that I would not have expected to happen with a more normal tyre. I had some RE003s, and they were shit in the dry, shit in the wet, shit everywhere. I would rate the RS4 and AD0x as being more trustworthy in the wet, once the rubber is warm. Bridgestone should be ashamed of the RE003.
    • This is why I gave the disclaimer about how I drive in the wet which I feel is pretty important. I have heard people think RS4's are horrible in the rain, but I have this feeling they must be driving (or attempting to drive) anywhere close to the grip limit. I legitimately drive at the speed limit/below speed the limit 100% of the time in the rain. More than happy to just commute along at 50kmh behind a train of cars in 5th gear etc. I do agree with you with regards to the temp and the 'quality' of the tyre Dose. Most UHP tyres aren't even up to temperature on the road anyway, even when going mad initial D canyon carving. It would be interesting to see a not-up-to-temp UHP tyre compared against a mere... normal...HP tyre at these temperatures. I don't think you're (or me in this case) is actually picking up grip with an RS4/AD09 on the road relative to something like a RE003 because the RS4/AD09 is not up to temp and the RE003 is closer to it's optimal operating window.
    • Either the bearing has been installed backwards OR the gearbox input shaft bearing is loosey goosey.   When in doubt, just put in a Samsonas in.
×
×
  • Create New...