Manual boost controller

Does anyone know if the MBC in this link is a ball and spring type. I want to try and tinker with the #1 turbo mod and it stipulates a ball and spring MBC instead of bleed valves.

http://cgi.ebay.co.uk/MANUAL-BOOST-CONTROLLER-KIT-TOYOTA-SUPRA-TURBO_W0QQitemZ220380670617QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item220380670617&_trksid=p3286.c0.m14&_trkparms=72%3A1689%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

i would save and buy an electronic one mate, no mass in these bleed valves

MBC's are a PITA on the GTE engine, they're a real pain to get working right and even then boost levels can vary considerably. Constant adjustment is needed. Tried two different one sone mine and couldn't get either to work right.

EBC is the way to go if you want boost control after BPU, they are only £100-150 for a decent one 2nd hand. Much less if you are put some time into it.

With regard to your question, if it doesn't stipulate ball and spring in the add, it's not going to be one. And for £15, thats to be expected.

Looks like it's a bleed valve.

http://turborevs.org.uk/Boost%20Controller.htm

http://cgi.ebay.co.uk/R-Spec-BOOST-CONTROLLER-KIT-FOR-ANY-TURBO-CHARGED-CAR_W0QQitemZ220383914231QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item220383914231&_trksid=p3286.c0.m14&_trkparms=72%3A1689%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

Thats the one you want there. Its definitely ball and spring.... if that means there is a spring and a ball bearing in it?

I have one sitting in front of me lol.

Thanks for the responses, I already have a AEM tru boost for controlling boost over and above 4k, I was just skimming over supraforums and noticed someone did the no.1 turbo mod(same one as is on max-boost) and figured i'd give it a go. I do like the idea of having 1bar on the first turbo and then 1.2 on the second! I nver really gave much thought to MBC's before reading the write-up so i'm not terribly clued up when it comes to picking one.

Cheers Scott, that one is indeed what i'm looking for and also looks a little more reputable than the others.

Thanks for the responses, I already have a AEM tru boost for controlling boost over and above 4k, I was just skimming over supraforums and noticed someone did the no.1 turbo mod(same one as is on max-boost) and figured i'd give it a go. I do like the idea of having 1bar on the first turbo and then 1.2 on the second! I nver really gave much thought to MBC's before reading the write-up so i'm not terribly clued up when it comes to picking one.

 

Cheers Scott, that one is indeed what i'm looking for and also looks a little more reputable than the others.

No worries, report back on how you get on with the mod, i fancy giving the tubby1 mod a run.

Make sure you do it the "safe" way though as there are a few dodgy ways to do it.

ignore the threads on supra forums and max boost, they refer to "UK" turbo's which are apparently ( ) slightly stronger than the jspec ones.

Plus, running such a high level of boost without having it mapped in, especially on jspec injectors and ECU is asking for det.

It's completely pointless/risky doing this unless you have a mapable ECU.

ignore the threads on supra forums and max boost, they refer to "UK" turbo's which are apparently ( ) slightly stronger than the jspec ones.

 

Plus, running such a high level of boost without having it mapped in, especially on jspec injectors and ECU is asking for det.

 

It's completely pointless/risky doing this unless you have a mapable ECU.

Could the same not be said for running the combined boost at 1.2 though?

Could the same not be said for running the combined boost at 1.2 though?

No, it's a completely different situation. Have a read of the max boost site and it'll explain how the sequential system works.

As mentioned in the other thread, it's efficiency ratio's gone out of the window X2, air temps x2, etc (it'll be a lot more than x2 though )

No, it's a completely different situation. Have a read of the max boost site and it'll explain how the sequential system works.

I know how it works though, i read through all the different versions of the mod and the last one (deemed the safest option) seemed sound. Certainly no more risky than upping the overall boost.

Our cars aren't mapped for 1.2 bar any more than the first is for 1 bar.

ignore the threads on supra forums and max boost, they refer to "UK" turbo's which are apparently ( ) slightly stronger than the jspec ones.

 

Plus, running such a high level of boost without having it mapped in, especially on jspec injectors and ECU is asking for det.

 

It's completely pointless/risky doing this unless you have a mapable ECU.

I have a wideband sitting ready to go on but no fuel control, I was hoping the injectors would cope with 1bar @3-3.5k seeing as they cope with 1.2bar @5k. But as they say, assumption is the mother of all mistakes. My other theory(assumption:)) was that aslong as you didn't get greedy with the boost from the first turbo, there would be enough exhaust pressure to spool the 2nd before the transition.

I have a wideband sitting ready to go on but no fuel control, I was hoping the injectors would cope with 1bar @3-3.5k seeing as they cope with 1.2bar @5k. But as they say, assumption is the mother of all mistakes. My other theory(assumption:)) was that aslong as you didn't get greedy with the boost from the first turbo, there would be enough exhaust pressure to spool the 2nd before the transition.

The horrible lean point on the BPU setup is at the switch over point and when the boost first starts to build on the 2nd turbo. If you already have a huge charge temp from the 1st then switch to 2nd at a far higher boost/temp level it's going to be det it's arse off when then 2nd comes online. The AFR gauge will be too slow to respond to spot this, it needs an aftermarket ECU with det monitoring when taking things to this level, and therefore mapping in.

Pushing the 1st turbo to such levels is very risky, it was only designed for 0.4 ish bar so will shorten life of it and the rest of the engine significantly without the changes being mapped in when boost pressures are raised by such a degree.

The horrible lean point on the BPU setup is at the switch over point and when the boost first starts to build on the 2nd turbo. If you already have a huge charge temp from the 1st then switch to 2nd at a far higher boost/temp level it's going to be det it's arse off when then 2nd comes online. The AFR gauge will be too slow to respond to spot this, it needs an aftermarket ECU with det monitoring when taking things to this level, and therefore mapping in.

 

Pushing the 1st turbo to such levels is very risky, it was only designed for 0.4 ish bar so wil shorten life of it and the rest of the engine significantly without the changes being mapped in when boost pressures are raised by such a degree.

Wow, i didn't realise stock boost was 0.4, i thought it was 0.7 lol. I wouldn't mind upping the boost in that case, but certainly not to 1bar. 0.6-0.8 at most.

I think thats the sound of my parade being pissed on:( I guess the only way to get corvette power delivery and torque is to buy a corvette.

I think thats the sound of my parade being pissed on:( I guess the only way to get corvette power delivery and torque is to buy a corvette.

You can still up it, just don't go nuts

Wow, i didn't realise stock boost was 0.4, i thought it was 0.7 lol. I wouldn't mind upping the boost in that case, but certainly not to 1bar. 0.6-0.8 at most.

Just to be clear, stock on the 1st turbo is around 0.4, with both online it's 0.76 bar.

With BPU you can *fairly* safely run 0.5-0.6 on the 1st turbo and up to 1.25 with both online, but thats pushing things to their limit.

You can still up it, just don't go nuts

Might give it a go, if I did it would only be a little bit and I think I'd have to set the valve externally as some of the guides tell you to install the valve wide open and gradually reduce the boost untill the slam starting of the 2nd turbo stops, to me that sounds iffy. Homer has a point though, there is a lean spot when the 2nd turbo comes on and I dont have a det mic, so it could run great untill I burst a ring land or something equally expensive.

Just to be clear, stock on the 1st turbo is around 0.4, with both online it's 0.76 bar

Yeah thats what i didn't know. I thought it was 0.7 first then 0.8 both for stock

Might give it a go, if I did it would only be a little bit and I think I'd have to set the valve externally as some of the guides tell you to install the valve wide open and gradually reduce the boost untill the slam starting of the 2nd turbo stops, to me that sounds iffy. Homer has a point though, there is a lean spot when the 2nd turbo comes on and I dont have a det mic, so it could run great untill I burst a ring land or something equally expensive.

That is the right way to do it buddy. You want the valve all the way open, if you have it closed the vacuum won't open the actuator and it will pop. MBC's work the opposite way from what you would think

When its fully open it works as stock, then just start to tighten it until the boost goes up a touch.

I think thats the sound of my parade being pissed on:( I guess the only way to get corvette power delivery and torque is to buy a corvette.

Or a nice big single kit

When its fully open it works as stock, then just start to tighten it until the boost goes up a touch.

Or just fit an EBC that has adjustable gain control control? It's far safer and has a lot less messing involved after it's installed and setup.

Or just fit an EBC that has adjustable gain control control? It's far safer and has a lot less messing involved after it's installed and setup.

Oh definitely, i think its just a trial run though

I fitted a bleed valve on my first turbo back in the day, and gave no noticeable power gain when upping the boost by a couple of psi, and a definite power drop when upping it a bit more - either overheating or the ECU pulling timing due to detonation, or both I guess. Disappointing especially after the time I spent on my quality installion

-Ian

I fitted a bleed valve on my first turbo back in the day, and gave no noticeable power gain when upping the boost by a couple of psi, and a definite power drop when upping it a bit more - either overheating or the ECU pulling timing due to detonation, or both I guess. Disappointing especially after the time I spent on my quality installion

 

-Ian

Did you notice a difference in the transition?