BPU New Manifold and BC installation

Hi

Has anyone had the need to replace the manifold for stainless for BPU? These are available which promise more BHP if replaced but just wondered if it was necessary. Also can anyone confirm whether a full JDM BPU system with 1 bar restrictor ring can be taken to the safe 1.2bar with a boost controller? If they act on the turbo I can see how that would be and therefore the restrictor ring would make 1 bar with no BC manipulation but just wanted to confirm it. Also I take it the BCs are mounted in the dash or are they an under bonnet mount? I am going for a Greddy as these seem to be the best for a Supe.

I ran bpu with a restrictor ring for 2 years with no problems. You will need a fuel cut defender though.

Yes I've already got the plugs in and will install FCD along with a full 3 inch system out to 4 at the back but ant to make sure its a reliable car too so going to go full BPU with a Boost Controller and a FMIC to make sure its as good as it can be but fully controlled.

So can anyone shed any light on the questions before I go out buying? Do I need a big hole in my dash for a BC or is it under bonnet and can it raise a BPU decat car with 1 bar restritor to 1.2 bar safely as others say?

I've never heard of changing the manifold for bpu tbh? interested in seeing a link to them as I don't know of one that would mean you keep the standard sequential system?

I still wouldn't bother with a boost controller but it is obviously up to you. They have some under bonnet plumbing in and some sort of solenoid (I'm no expert) and then a display for inside, either dash/steering column etc.

I think restrictor ring at 1 bar and boost controller to up to 1.2 is an ok/standard strategy yes, my view is why not just set up the restrictor ring for 1.1bar?

I think to explain my situation would be more helpful - I live in lincolnshire and in my town only one garage will entertain even serviciing a Supe. It seems most garages in my area run a mile - but I could get a specialist to fit a BC and then put it intermittently at 0 effect (excuse me I dont know ow they work) to get a decent 1 bar and probs near 400 safe bhp to 1.2 at the tough of a button to get between 390 and 430 (according to people on here who run them, again, not my experience). Of course to save a few hundred and go for 1.1 bar would be great but how would I do this, is there a pre defined diameter on a 3 inch system or would I have to keep taking the catback off (which I assume is where the ring goes as most people recommend as far back as possible it seems?) and grinding another mm then reassembling and test running?

And thanks again Scooter, you have been the most helpful person to me on this board, I have owned three Supras and periodically been on here and have never found anyone nicer over the years!

Hiya mate, to get a a garenteed 1.1 bar you need a res ring that you put between the end of the 1st decat and beginning of the second decat then use the boost controller to set the bar, you can run up to 1.2 bar of boost with no issues. You will also need

Full pump ie walbro 255/450 what ever you like

Ngk bkr eix 7

Front mount intercooler

Hks fcd

Both decats

A 3inch exhaust

And restricter ring.

If you struggle to get a place to help then if your willing to come to me I’m more than happy to help you fit everything apart from the fcd and fuel pump but you could make a stop at SRD to have those fitted if not everything depending on what you want to do mate :-) hope this helps

No problem, thanks for the kind words, i was (still am in many ways) like you and finding my way via help from the site.

If you can get a local place to decat you and fit the fuel pump etc then with a conservative restrictor ring (from Chris wilson etc on here) you will limit the boost regardless of your cat back.

I bought a bpu car with an iffy controller or plumbing and just took it out of the system and went with the basic restrictor ring way. Now yes it did take a few goes at grinding to open it up sufficiently however you only need to access the cat back-2nd cat exhaust joint, undo the bolts here and lever with a screw driver and the 2-3mm restrictor ring will drop out. So if you have a ramp (mine are scaffold boards screwed together) then you can do it easily. The trouble you have is if you don't diy it at all the labour for setting this up is probably the same or more than fitting a boost controller?

You could always just initially fit the catback and enjoy a bit more power and the noise (boost should go up a bit), with the stock fuel cut in place you'll struggle to do any harm, it's a very good safety feature that pretty much stops any of the really catastrophic stuff happening.

It's a bit old school but you could also remove the second cat when fitting the cat back exhaust and then you should get close to fuel cut, but also see a noticeable improvement in performance.

http://www.mkivsupra.net/vbb/showthread.php?247973-Removed-2nd-cat-only-Restrictor-Ring-needed&highlight=restrictor+ring

Lee's way is the proper all bells and whistles way (apart from imo the front mount intercooler is not 100% necessary)

I know what you are saying and thanks for the kind offer to help too, and I can see where you are coming from Scooter, obviously a BC aint cheap and I could use that money on something else (Supe related) - But...... I want the BPU to be a transformation in one step, to take my car from 0.76 to 1.2 all the way up to the safe max and I am ok paying the thousand or so quid to do it, to be honest I bought a Supe that needed so much work doing and cost so much to get to where it is now its a drop in the ocean to unleash its full potential now, but all well worth it. Other than the BPU set up there will then just be the valve seals, air con piping and then interior and it will be pucka. My current exhaust is standard apart form a big muffler that seems to be welded on to the end so the jump in performance should be staggering and after so many bils where you just get 'peace of mind' instead of any notable increases in performance, handling etc it will be somewhat different.

I assume the Greddy is what everybody goes for, anyone on here who has one of these and if so did they dash mount it or does it come on its own mount or box for bolting? I am going to get a new dashboard too and I dont want the hassle of mounting it twice which is why I am asking?

These (http://www.garagewhifbitz.co.uk/greddy-profec-3506.html) seem to be the boost controllers that everyone on here goes mad for when they come up for sale.

Personally, I don't like the greddy boost controllers. Admittedly my only experience of them is with an old profec, but I found them such a faff to setup correctly.

I'm currently using a gfb geoforce II, which I think is really good. I made a simple bracket for it, to mount just in front of the gear stick.

You need to fit a restrictor ring, to stop the turbos creating too much boost that can't be controlled. Typically, a restrictor ring is basically a gasket with a 2" diameter hole. You then use a boost controller to raise the boost past 1bar, where it can be set and monitored accurately.

They are dead easy to fit, and there are various threads on here with fitting instructions.

You don't need a fmic for bpu, but considering the age of factory components, it's wise to upgrade to something fresher. If you want to retain your air con, you will find it a very tight fit with fmic pipework, but it can be done, as I have.

As Lee said above, you'll want to fit a set of plugs with the heat range 7. A walbro 255 actually flows less than a stock pump, but will still easily support bpu, and is a good idea to replace a 20 year old pump.

You should also consider changing the coil pack clips if you haven't done already. It would be worth buying some before attempting to unplug yours, and have them crumble in your hands, leaving you unable to put it back together.

Omg that's some interior the combination of materials. Omg.

When I bought my car it had just a 2.5" 2nd De-cat and a 3" exhaust and on a cold night I would hit factory Fuel Cut.

I have since fitted a 3" first decat, 1 bar Restrictor ring, a fuel cut defender and a early Greddy Profec.

If you are looking to save a few quid then I would look through the classifieds and you will probably find what you need 2nd hand. the only thing I bought new was the First de-cat.

The very first Greddy Profec Boost controllers are simply 3 knobs, one for cut speed ( doesn't need adjusting really ) One for how much low boost and one for high boost, and there is a button to switch boost settings. its very simple.

In Regards to fitting stuff yourself, I would say 2nd De-cat and exhaust is simple enough, as is the boost controller and Fuel cut defender as they are very well documented installation instruction available off the forum and generally on the internet. The one thing I struggled with on a driveway is the first de-cat.

I spose my point is does anyone really adjust theirs for different circumstances once it's all fitted. Before I disconnected mine it had I think 4 settings and then a 'scramble' one where it added on a bit to the max setting, it sounded like a temptation/grenade setting! As it wasn't working properly and due to my naturally cautious nature I think I just thought let's get 1.15 in the winter and leave it at that! Best feature for me was the ability to set an audible max boost warning and it recording peak boost.

Fulcrum I get the one hit spending and it certainly will be transformed pace wise in the second turbo range, it will be a bit of an animal compared to stock so careful if you are getting it done at this time of year as you'll not be able to fully utilise it in these temps.

I spose my point is does anyone really adjust theirs for different circumstances once it's all fitted. Before I disconnected mine it had I think 4 settings and then a 'scramble' one where it added on a bit to the max setting, it sounded like a temptation/grenade setting! As it wasn't working properly and due to my naturally cautious nature I think I just thought let's get 1.15 in the winter and leave it at that! Best feature for me was the ability to set an audible max boost warning and it recording peak boost.

 

Fulcrum I get the one hit spending and it certainly will be transformed pace wise in the second turbo range, it will be a bit of an animal compared to stock so careful if you are getting it done at this time of year as you'll not be able to fully utilise it in these temps.

I agree with you, you don't tend to change the boost settings. Easiest thing to do is fit a restrictor ring for 1.1 bar and just drive it.

Speak to Chris Wilson for restrictor rings.

I guess I'm of that mentality though that I'd be sat there at 1.1 bar at the lihts and some Johnny 1.2 bar would pull up next to me and..... I feel like I would always be wondering what that extra .1 would be like for the sake of a few quid saved! I also note nobody is mentioning an AFR gauge on here, does nobody at all bother with that and is it just overkill?

Racing off traffic lights? Are you 12

And thanks for the concern Scooter I am a much more sage driver these days and only blast when I know its a good idea. My first Mk IV I took out in the rain the first day and slid out of a roundabout sideways. You dont forget that...... I've got a Beemer 535D twin T too which takes on all the winter has to offer for safety sakes!

Oh yes, sorry, we all stick to the speed limit at all times Mk4Gaz and only ever go fast on 'track days' despite heavilly modding our cars. Yes, I think that covered it......

You are talking to someone who never modded any of their first 4 TT's! So the 1.1 or 1.2 doesn't really bother me.

I've modded the first turbo for more boost pressure though which made as much difference to me as the top end 0.7-8 to 1.1-2 bar change.

Having a boost controller made a big difference. As you can bring the boost on more aggressively. Run 1.3 bar will be fine haha I did for over a year.