BPU Boost Controllers

[Fulcrum2000]

Hi All

 

So my mechanic set up my Supra with the HKS EVC VI IR BC and it turned out it was overboosting, as nobody seems to use this BC on a Supra I've been advised to use 2 separate BCs on one turbo each, the first being .85 and the second being 1.2. Is this right and can anyone recommend the best cheapish BCs to run in tandem in this way? Thanks in advance.

[Frank Bullitt]

So boost creep? The exhaust is flowing more than the wastegate can handle? Do you have a restrictor ring in the exhaust?

 

Are you using a three port solenoid?

 

When you say two controllers, do you mean one for pre-spool and another post pressure?

 

At what RPM is everything happening?

 

Are you wanting to run the OEM twins, sequential of TTC?

[Mike2JZ]

You dont need two separate boost controllers. Nothing wrong with EV6 controller. You are overboosting because it has been setup wrong in the calibration, or your mechanic has plumbed it up wrong.

[Scooter]

I have a setup that does about this, 0.85 and 1.15 and it's just a filed restrictor ring, and then a little bleed value setup on the rear sequential pipework.

 

I can't change the 1.15 bar figure but can tweak the 1st turbo boost from stock to the 0.85 (you can go more but it's risky and not worth it)

 

Controllers always seem to be a massive faff and I don't think you can limit the boost with them.

[Mike2JZ]

I have a setup that does about this, 0.85 and 1.15 and it's just a filed restrictor ring, and then a little bleed value setup on the rear sequential pipework.

 

I can't change the 1.15 bar figure but can tweak the 1st turbo boost from stock to the 0.85 (you can go more but it's risky and not worth it)

 

Controllers always seem to be a massive faff and I don't think you can limit the boost with them.

 

You can't limit the boost with a controller, you can only raise boost with a controller.

 

For you to have good boost control there needs to be a good mechanical wastegate pressure setup. AKA, when you have the turbo actuators running directly off wastegate (no external boost controller of any sort), there should be no boost creep etc. It should hold a steady pressure to redline. On a decent BPU setup this should be around 7-10 psi on first turbo, and 10-14psi on second turbo, all depending on types of turbo's used, decats, exhaust system etc etc.

 

If you are getting boost creep with wastegate pressure you have a mechanical issue that needs addressing, otherwise trying to put a boost controller on top if that is going to achieve nothing.

[supra_aero]

You can't limit the boost with a controller, you can only raise boost with a controller.

 

For you to have good boost control there needs to be a good mechanical wastegate pressure setup. AKA, when you have the turbo actuators running directly off wastegate (no external boost controller of any sort), there should be no boost creep etc. It should hold a steady pressure to redline. On a decent BPU setup this should be around 7-10 psi on first turbo, and 10-14psi on second turbo, all depending on types of turbo's used, decats, exhaust system etc etc.

 

If you are getting boost creep with wastegate pressure you have a mechanical issue that needs addressing, otherwise trying to put a boost controller on top if that is going to achieve nothing.

 

Totally correct. And failing that I need a boost controller and you can sell it to me immediately for a good price in these trying times

[Fulcrum2000]

So boost creep? The exhaust is flowing more than the wastegate can handle? Do you have a restrictor ring in the exhaust?

 

Are you using a three port solenoid?

 

When you say two controllers, do you mean one for pre-spool and another post pressure?

 

At what RPM is everything happening?

 

Are you wanting to run the OEM twins, sequential of TTC?

 

So basically I dont know how its been plumbed in wrong but at full chat it read 33.3PSI on WOT (even though the HKS 6 is set up to have a maximum on all 3 readings of 17PSI) - whether that is both turbos at full or whatever I dont know, it isnt monitoring atmos pressure, its zero till the sound of spool, I also notice the spool sound is louder since I had it installed (only slightly but noticeable). The problem is with the current situation the tuner is not available and is looking like he might go out of business altogether. There is another very good mechanic in my town who has agreed to fit two controllers next week but what I ideally want is one cheapish manual for the first turbo that can take it to .8 and maybe all under the bonnet, and then one into the second which will take the second to 1.2. If I do this set up will the ECU make them both activate and spool in the right order at the right time or will having two BCs interfere? My understanding is the car still controls everything but the controllers allow the boost to be at a higher maximum? I switched the HKS down to 16.5 and the max was then 29.9 but as I dont know if it is reading one or both turbos I dont want to cause potential damage and have to have my turbos rebuilt or repaired. I think I've got away with having no damage as the car doesnt smoke on idle or when boosting but I really want to get it sorted whilst we're in lockdown so its ready when we're allowed out without having to dodge police alsatians.

 

I am if you didnt know JDM 93 Auto at BPU with a 1 bar restrictor in the exhaust from WB, have A CW FCD, Walbro 255, 3 inch full decat stainless system and basically spent money to get the most recommended set up but seem to be failing at the final hurdle on the boost controller. The whole engine has been rebuilt with forged pistons and had perfect compression so I should really be as close to a BPU max as possible if I can actually get the darned boost to the right level!

[j_jza80]

Has the car been de-catted? And if so, was a restrictor ring installed?

[Fulcrum2000]

I should also clear up I want to run the stock twins as twins at the best possible norm, not TTC or anything, I love the power delivery of true twins

[Frank Bullitt]

I should also clear up I want to run the stock twins as twins at the best possible norm, not TTC or anything, I love the power delivery of true twins

 

So sequential as apposed to parallel? TTC stands for true twin conversion and is parallel.

 

Are your VSVs all working correctly? Have you any photos of the engine bay? As Mike says you don’t need two controllers but that doesn’t mean you can’t!

[Mike2JZ]

So basically I dont know how its been plumbed in wrong but at full chat it read 33.3PSI on WOT (even though the HKS 6 is set up to have a maximum on all 3 readings of 17PSI) - whether that is both turbos at full or whatever I dont know, it isnt monitoring atmos pressure, its zero till the sound of spool, I also notice the spool sound is louder since I had it installed (only slightly but noticeable). The problem is with the current situation the tuner is not available and is looking like he might go out of business altogether. There is another very good mechanic in my town who has agreed to fit two controllers next week but what I ideally want is one cheapish manual for the first turbo that can take it to .8 and maybe all under the bonnet, and then one into the second which will take the second to 1.2. If I do this set up will the ECU make them both activate and spool in the right order at the right time or will having two BCs interfere? My understanding is the car still controls everything but the controllers allow the boost to be at a higher maximum? I switched the HKS down to 16.5 and the max was then 29.9 but as I dont know if it is reading one or both turbos I dont want to cause potential damage and have to have my turbos rebuilt or repaired. I think I've got away with having no damage as the car doesnt smoke on idle or when boosting but I really want to get it sorted whilst we're in lockdown so its ready when we're allowed out without having to dodge police alsatians.

 

I am if you didnt know JDM 93 Auto at BPU with a 1 bar restrictor in the exhaust from WB, have A CW FCD, Walbro 255, 3 inch full decat stainless system and basically spent money to get the most recommended set up but seem to be failing at the final hurdle on the boost controller. The whole engine has been rebuilt with forged pistons and had perfect compression so I should really be as close to a BPU max as possible if I can actually get the darned boost to the right level!

 

If you are not doing the work yourself and are relying on a mechanic, then please do yourself a favor and visit a supra specialist before you blow up your turbos and engine running 30psi of boost. There are a few specialists scattered across the UK, all of which will be capable to setup a boost controller. Its pretty simple.

 

Adding a second boost controller is not going to solve your problem. Do not do this. (Although technically possible, but not needed for this scenario, so lets keep it simple :3)

 

Failing that, if you are capable of picking up a spanner and taking some photos of whats been done in terms of vac hose plumbing between your boost controller solenoid and turbos, then we might be able to crack this problem via the forum members knowledge.

[Scooter]

My car came with a boost controller but it wasn't working properly and it's now just a boost gauge with a high boost warning function.

 

I removed it's control part pipework and just left the bit where it was 'T' into to read the boost pressure. If you run it with otherwise stock pipework you can then see if it over boosts, if it does your restrictor ring is not restricting enough!?

 

You should then get 0.7 bar 1st turbo and with a correct ring 1.15/1.2 bar on both. To adjust the 1st turbo up you can tap into the pre spool circuit and adjust a valve (got mine from eBay) and by trial and error get it to 0.85.

 

Then you can just leave it, you can't adjust it on the fly, or go 1.25/1.30 bar for a minute or two like you can with a boost controller but it'll work and once set you can't accidentally overstep the mark or get carried away in the heat if a moment etc

[Fulcrum2000]

If you are not doing the work yourself and are relying on a mechanic, then please do yourself a favor and visit a supra specialist before you blow up your turbos and engine running 30psi of boost. There are a few specialists scattered across the UK, all of which will be capable to setup a boost controller. Its pretty simple.

 

Adding a second boost controller is not going to solve your problem. Do not do this. (Although technically possible, but not needed for this scenario, so lets keep it simple :3)

 

Failing that, if you are capable of picking up a spanner and taking some photos of whats been done in terms of vac hose plumbing between your boost controller solenoid and turbos, then we might be able to crack this problem via the forum members knowledge.

 

Cheers for everyones info but just to clarify I intend to rip out the HKS even though it cost 600 quid and plumb in either two BCs or one bleed on the first and a BC on the second to allow safe boosting, what is the best hardware for this? Money isnt a problem but the most expensive isnt necessarily the best.

[Fulcrum2000]

Cheers for everyones info but just to clarify I intend to rip out the HKS even though it cost 600 quid and plumb in either two BCs or one bleed on the first and a BC on the second to allow safe boosting, what is the best hardware for this? Money isnt a problem but the most expensive isnt necessarily the best.

 

 

Looking at all your answers I think Scooter is right - if I get a bleed valve on the first and have it up to .85 and a traditional BC on the second one up to 1.2 that gives me full BPU at the most safe set up is that right? And this will work fine with a 1 bar restrictor plate? Excuse my ignorance I assume it is fine as its going over that with the restrictor plate in now but I just wondered. If this is ok whats the easiest most reliable BC for the second turbo that everyone uses and Scooter what is the valve device called on ebay so I can pick one up? I'll obviously confirm all this with my mechanic too before buying.

[Style]

Cheers for everyones info but just to clarify I intend to rip out the HKS even though it cost 600 quid and plumb in either two BCs or one bleed on the first and a BC on the second to allow safe boosting, what is the best hardware for this? Money isnt a problem but the most expensive isnt necessarily the best.

 

Why are you on here asking for advice and then proceeding to completely ignore said advice? Mike is about the most reliable source on this forum for this kind of thing and therefore one of the best people to advise you on what to do. Best thing to do is get some photos up so we can try and solve the issue, not mask it with multiple controllers.

[Fulcrum2000]

Why are you on here asking for advice and then proceeding to completely ignore said advice? Mike is about the most reliable source on this forum for this kind of thing and therefore one of the best people to advise you on what to do. Best thing to do is get some photos up so we can try and solve the issue, not mask it with multiple controllers.

 

With the greatest of respect to those answering I think you are misunderstanding my replies. I am not suggesting I add a second controller to the first one which is clearly and inherently wired up incorrectly, I am going to remove the HKS 6 completely and replace it with a more user friendly system of either two simple BCs or one and a bleed valve to just slightly increase the first turbo and bring the second one up to safe BPU. Can I just make it clear now (and again no offence) that this is my intention and always was my intention right from the outset of this thread.

 

And I appreciate the advice on going to a Supra specialist but the nearest one to me is, well, not near to me and of course its not possible to reach them for the forseeable. And this HKS wasnt set up by some back street mechanic, it was a tuning specialist with Tom Hudson on video call whilst he did it who I believe is one of the best tuning experts in the country and now runs FenSport Performance. According to the tuner who did it the HKS was 'the most awful piece of kit he'd ever used' and Tom Hudson thought the same. So, and I know I will get some flak for this, I would say anyone out there who is considering buying the latest HKS EVC, if its going near a twin turbo, think again. They are just plain awful and nobody knows how to set them up properly. It cost me nearly 600 quid and I will be selling it as soon as I can get it grafted out of my car, I see they go for a couple of hundred on ebay and not surprisingly there are some on there.....

 

So back on topic, I agree it would look a bit 'carnival' to have two BCs with head units running to my dash so the obvious choice is a small block to the first to hit .8 or .85 and then a standard BC with a head unit running the second turbo to 1.2bar. With that in mind what exactly is this device on the first turbo called so I can find one today on EBay or Amazon and assuming all HKS systems are equal and I dont get one of them what BCs are others using for their second turbo BPU?

[Scooter]

It does seem to me like your restrictor ring is too large, so I'd get one of them too, Chris Wilson's will be definitely small enough.

 

For me I didn't want different boost levels, I settled for a happy/safe (i think) medium. I and the car was up and down like a yoyo for a few hours, taking out the restrictor ring, filing it's internal diameter larger, refitting, taking it out for a spin, checking max boost, til i now get 1.15, and occasionally over, my boost controller (now just gauge) has a nice audible warning feature. I've not touched the restrictor ring since, all I miss is the ability to fine tune up or down now with a button or dial, but I'm happy with the fixed setup.

 

The t piece adjustable bleed screw thingy I added after being disappointed with the 1st turbo performance, is plumbed in to the prespool part of the vsv's and again is adjusted incrementally in small stages to creep the 1st turbo boost up, I've read this can be more risky for the turbo and you shouldn't go mad.

 

So for me boost wise the mechanical adjustment of the restrictor ring and this bleed valve (that's got an allen key securing lock) work and aren't a risk if you read up on what's going on and don't rush setting them up? Mine was made easy by having the boost gauge with a warning limit and peak hold function.

[Ric]

You've still not answered if you have a correctly sized restrictor ring. If you don't, stop and fit one or you're going to blow something up.

[Style]

Fair play, apologies in that case!

 

The TT system isn't something I know much about as I skipped it But hopefully you can get it sorted

[Fulcrum2000]

You've still not answered if you have a correctly sized restrictor ring. If you don't, stop and fit one or you're going to blow something up.

 

Hi

 

Yes I do have a correct restrictor ring, I got it from WB and before the next stages it was hitting .95 on my boost gauge. I also have an AFR and its never gone into dangerous levels even though the car seems to be overboosting so hopefully the overboost hasnt caused any issues.

[Ric]

If you turn off the boost controller completely you see 0.95 bar on full boost? Thats about right.

 

So the issue is with your boost controller configuration or plumbing IMO

[Fulcrum2000]

If you turn off the boost controller completely you see 0.95 bar on full boost? Thats about right.

 

So the issue is with your boost controller configuration or plumbing IMO

 

I would absolutely agree Ric - I want to upload pics but the forum just says upload failed?

[Fulcrum2000]

 

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[Fulcrum2000]

 

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Didnt realize there was a 2mb file size limit, modded all the pics now so you should see them.

[Mike2JZ]

Spaghetti junction there. No wonder you are having issues. Completely different to any HKS boost controller I've plumbed in, looks so wrong I'd RIP out the plumbing, put it back to stock then start again. When I get home tonight I'll upload some photos and diagrams you can follow