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Boost controller's and BPU


MrHanky
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Hi,

 

I have been searching for an answer to this question, but cannot find a definative answer. I am looking to go BPU in the next 2 months or so and have started purchasing all the bits I need. I have also started getting quotes from various places and whilst talking to a very well respected member on here was told that a boost controller is not recommended.

 

Now I fully appreciate that this member know's 100% more about performance cars than me, but why do other garages recommend boost controllers?

 

What are other peoples opinions on this?

 

Thanks

 

Mark

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Although my car in off the road I recently went BPU, and I had and have no intention to fit a boost controller unless when I get the FCD set correctly I do not reach the 1.2 bar then yeah I will get a boost controller to do what it's built for and thats raise the boost and control it.

 

It is a personal choice.

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Most Jap cars will boost over 1.2bar (not good!) when the cats are removed and therefore require a restrictor ring to bring the boost back down to your desired level - most choose 1.0 bar.

 

...however some jap cars (including mine) only increased the boost to about 1.0 bar without the need for a restrictor ring. i have been told this is unusual but not uncommon.

 

I therefore added a boost controller to increase boost to 1.2 bar (my desired level). However please not on extreme cold days i have to adjust the controller or even turn it off thus not to boost over 1.2bar.

 

So in a nut shell. By removing the cats most Jap cars boost over 1.2bar (not safe) so they add a restrictor ring to reduce back to 1.0bar but then add a controller if you wish to increase boost to your desired level.

 

hope this helps.

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In order to clarify what i think Mark is trying to say, You dont normally NEED a Boost Controller.

 

The Wastegates on the Jspecs dont ALWAYS (yet there are exceptions) Cope well with the increased boost and so allow 1.2 bar anyway even without a boost controller.

 

The restrictor ring prevents the Turbos from generating 'runaway boost' since the overpowered wastegates wont stop it.

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So whats a safer bet for someone who wants to BPU a JSpec @ 1.2 bar max.......

1) Restrictor ring that allows up to 1.2 bar in wintertime (may need some toing and froing with ring sizes and there may be the odd boost spike over 1.2 bar ??)

2) Restrictor ring for 1 bar, plus a boost controller (more expense)...(does a smaller restrictor ring cause any issues when upping the boost with a BC ??)

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Thanks for your input guys. The argument against the boost controller according to the guy I spoke too, was that by fitting say a 1 bar restrictor ring and then upping the boost to 1.2 bar puts extra strain on the turbo's (this is how I understood it anyway). So it would seem that there are cons to both approaches.

 

1) If you go the boost controller route you add extra strain on the turbos when running higher boost than the restrictor ring.

 

2) You don't place the extra strain on the turbos, but since you will be running 1.2 all the time (assuming you use 1.2 bar ring) you can over boost into dangerous boost territory.

 

Is what I have put above correct? or am I being a numpty? :)

 

Thanks

 

Mark

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A restrictor ring doesn't put more stress the the turbo, if you run the car with a restrictor ring set at 1.2 or 1.0 with boost controller to up it to 1.2 turbo's are running the same stress. you just have more control over boost with a controller, if you go for just the restrictor ring only set it to 1.0 bar so you don't over boost in the winter or buy one for winter and one for summer.

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I'd go for 1 bar restrictor ring and boost controller, with the boost controller you can up the gain and make the turbo's spool up quicker and have more control over boost in summer and winter.

 

i'd go with jayssupra on this,ive a 1.2 resistrictor + boost controller to run 1.45 but i know everyone cains this much boost on stock turbos,but in my defence its been like this for over 4 years now.

 

i love the difference in spool with the boost controller on and would say money well spent even when the controller still only makes 1.2 bar

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,ive a 1.2 resistrictor + boost controller to run 1.45 but i know everyone cains this much boost on stock turbos,but in my defence its been like this for over 4 years now.

 

I wouldn't promulgate this kind of advice to people seeking info on BPU questions as it is simply incorrect. 1.45bar is not good for any stock tubbies! You've been very lucky mucka!!

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The trouble is when going BPU, not everybody gets the same results, as already said some don't need a RR and some need to spend a lot of time trying to get the right size for the required boost, in my case i under boost, so i have decided to keep the size of RR and up the boost with a controller to get the added benefits of faster spool up and a good control over boost spikes, and also have the ability to have instant control over summer/winter boost variations.

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With a smaller diameter restrictor ring to keep boost to 1bar and then raise further with an EBC, you have more restriction in the exhaust system and with that higher EGT's (Exhaust Gas Temperatures) for the same 1.2bar boost.

 

IMO if you want 1.2bar boost, fit a restrictor ring that should see 1bar boost normally and keep filing it out a little until you see a natural 1.2bar. As it's cold just now, it's likely this will be the most boost you see and it will drop slightly in the summer.

 

Spool up is pretty damned instant in the Supra so I don't see there's much benefit in buying a £200 + EBC, and I'm normally an advocate of fitting an EBC for most turbo cars.

 

The best route for me at BPU with FMIC looks like the new MAP2 piggyback ECU with built in boost control that looks a real bargain, given you can now map both ignition timing and fuelling to optimise your setup now and be able to make the necessary adjustments for the logical next step of a big single and larger injectors etc in future. This is also when you need the EBC function to raise boost on a turbo with appropriately sized wastegate.

 

Cheers,

 

Brian.

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My experience was pretty much the same as Suprasteve. I went BPU to find with a 1.2bar RR in I only made 0.9bar. So I took the RR out completely and then made 1.2 (this was in the summer).

 

That was ok for then, but it would obviously be spiking now. So I put the ring back in and bought an EBC to up it to the desired 1.2

 

I really can't comment on whether this is healthy or not in regards to EGT's as I know feck all about the inner workings of a Sup.

 

Although, nobody raised any concerns about an EBC with RR on this thread I started

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I think I am going to use a boost controller. I have just spoken to Mark at Phoenix Watford (as I wanted to get a quote from them anyway) and after talking with him about this, he recommends fitting a controller. He can see the other members reasons for not using them, but in his opinion if going BPU and adding a FMIC he would use a boost controller.

 

Thanks again for the the help people.

 

Mark

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you after more power already lol,, when are we going to see some uk pics ?

 

lol, yep i just in the process of getting quotes and parts for BPU :)

 

I realised yesterday actually that I havent put any pics up since picking the car up. I have some in my garage which I took in the works car park but I could do with taking some better ones.

 

Mark

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Safest- option 2 without doubt, prevents boost spikes & lets face it, how long are tubbies going to last at 1.2bar?

 

I am in the process of going BPU but this has got me thinking of the reliability of the stock tubbies at 1.2bar. So my question is for all of you BPU'd guys with 1.2 bar rr, How long have you been BPU at this boost level and have you had any problems regarding the stock tubbies?

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I am in the process of going BPU but this has got me thinking of the reliability of the stock tubbies at 1.2bar. So my question is for all of you BPU'd guys with 1.2 bar rr, How long have you been BPU at this boost level and have you had any problems regarding the stock tubbies?

 

Really depends on how the car has been treated, there are plenty of people had no issues with BPU using stock tubbies after a few years but then you do hear of the odd one going after a short time.

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I am in the process of going BPU but this has got me thinking of the reliability of the stock tubbies at 1.2bar. So my question is for all of you BPU'd guys with 1.2 bar rr, How long have you been BPU at this boost level and have you had any problems regarding the stock tubbies?

 

 

15,000 miles and still going strong (touches wood).

 

However my turbos may have been new when i bought it...I only have the dealers word on it. (he was not a dealer on the forum)

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