Blitz boost controller

[Keith C]

Right - I know I said I wasn't going to get one, but someone has offered me a Blitz DSBC for £100, second-hand, which seems too good to refuse.

 

Thing is, it's off a Skyline, so I just wanted to make sure that it would fit to my car without any problems, or if there are different fitting kits specific to each car.

 

Anyone know?

 

Cheers

[Alex]

As long as the wires and pipes reach it will be fine...test install before purchase if possible.

[Adam W]

You lucky git, I paid about £300 for mine! It is blue though

 

Basically you need a +12V ignition, +12V switched, and ground on the wiring side. Then there is a two-pin multiplug which goes to the solenoid, and a 3mm hose that goes to a vacuum line for the boost pressure. It's not car specific at all.

 

I also have a manual which I could scan or photocopy if you're stuck, but it looks like it's a photocopy anyway so I don't know what the quality will be like!

[Keith C]

Well I was just after making sure an ex-Skyline bit would go ok onto my car.

 

Cheers though guys.

[Steve W]

SORRY to butt,

 

where does the solenoid go ?

 

Does it replace the normal wastegate ?

 

[ I presume it must, otherwise, wouldn't the wastegate open

BEFORE the new solenoid anyway ? ]

 

Steve.

 

( only prying, in case I decide 'enough' is NOT 'enough' ! )

[Adam W]

You cut the hose which goes between the wastegate and the outlet pipe from the turbo (which is at manifold pressure), and fix it to the solenoid so it goes

 

outlet pipe - solenoid - wastegate.

 

The olenoid valve opens and closes according to instructions formthe boost controller, bleeding off different amounts of air, and allowing different manifold pressures before the wastegate opens.

[Steve W]

SO, the 'pressure' has to get through the solenoid before

it can open the wastegate ? (ie. the solenoid's 'in-line' ?)

 

ie. the solenoid can 'hold-up' pressure longer/higher hence raise

boost ?

 

[ if that's right - how can it possibly LOWER boost as Terry-TRD is saying

on another thread ? surely the wastgate isn't gonna open till its

set pressure no matter what ? that is, you can raise by holding-back

but how can you lower without altering wastegate/bypassing

wastgate with NEW outlet ? ]

 

NOT arguing with ANYONE - still yet to get my head round it all

(if I ever can ! !)

 

derrrr.....Steve.....I think......

 

ps. suppose it'll be easier once I've SEEN a couple of the things

in-situ.

[Branners]

You are right, it generally doesnt make sense, theres no way it should work, but it does. You can hold down the boost on an overboosting car.

 

Leon knows how, I never asked him how its done but he has done it a few times now.

 

JB

[Steve W]

I know this sounds stupid, BUT,

 

at what sort of revs' is the Soop making 'max' boost pressure ?

(std. turbos )

 

(Never bothered with a gauge in my RS, so, never really knew

if max' boost is near highest revs OR it's already there at ~ 3/4's

revs - ie. ~4/5,000 ? ? )

 

 

OBVIOUSLY the boost controller can only raise the MAXIMUM boost

 

it can't increase boost BELOW that 'revs' - it's only raising the LIMIT

not altering the WAY it's produced ? ?

 

(It's effectively a more refined way of 'screwing the wastgate

down tighter' ? )

 

Steve

 

ps. AND ALSO, I presume most (or all?) of the Boost Controllers

have a boost 'gauge' as standard ? ?

Is there any point buying the mechanical gauge seperately ?

(obviously I should get the mech' if I'm NOT getting a controller !)

[Ian C]

It's probably about 4500ish rpm or less on stock, as the second turbo only gets engaged at 4000 and then only goes up to about .8bar.

 

A boost controller can help some turbo systems hit maximum boost faster, but not in the Supra. The boost pressure forces open the wastegate, which means as pressure rises the wastegate starts opening and less exhaust goes through the turbo, so the boost pressure slows down in it's buildup.

 

That's why we have a VSV in place. No pressure gets to the actuator until a set boost value has been hit, and then bang - it opens, the wastegate pops open immediately, and boost production is maintained at a set pressure.

 

The aftermarket solenoid does sort of the same thing, except it opens and shuts at the correct rate to balance the wastegate open enough to maintain boost at whatever pressure you want.

 

So, you will still hit your 0.8bar as quickly as you used to, but it will take a bit longer to get to, say, 1.2, therefore perceived lag increases despite things still happening at the same rate.

 

Does that help in any way?

 

-Ian

[Steve W]

" OH GOD..........NUROFEN.....NOW ! ! "

 

Yes, thanks Ian.

 

So ~4,500-ish, so using the boost controller will raise boost

 

after that ? And 'up-to' the set level (as long as turbos can

 

supply the set level of boost - obviously if they can only

 

make say, 1.2Bar it's never gonna reach 1.5, even if you tell

it to ? ?

 

Bit like my 'technical-schematic' below ? ? > >GISSA' JOB

 

S.

 

AND, if anybody laughs........FAIR COP !

[Ian C]

That's just got to be the best boost map I ever saw

 

Well, it's all complicated by the sequential operation, because #2 turbo doesn't get to do anything until around 4000rpm anyway, but it *is* prespooled at 3500rpm by the exhaust gas not being used to drive turbo #1 (which is also the way #1's boost level is controlled).

 

So, #2 get's a bit of a run up, then comes fully onstream at about 4000rpm - hence the famous number two turbo kick-up-the-arse-whoops-wheres-my-traction-gone power delivery of the Supra.

 

You now have both turbos onstream. Boost pressure raises much more quickly now as two turbos are supplying pressure.

 

With no boost creep and a sorted, fully set-up boost controller, you will hit whatever you have programmed in.

 

The *minimum* boost would be whatever you get when the wastegate is wide open. Anything above that is generated by the boost controller stopping the wastegate from opening fully.

 

The turbos will boost to whatever you want, all the way to self-destruction (overboosting), so if you ask for 2bar, you may briefly get it

 

And I think your main question was

"So ~4,500-ish, so using the boost controller will raise boost after that ? "

Well, all it does is raise the limit of boost. It's completely rev-independant. How quickly you get to that level of boost depends on throttle position and gear. It just that the sequential operation gives us this artificial starting point of 4000rpm and then buggers that by having a prespool, so it's all a bit up in the air! Of course, if your maximum boost is higher than stock, it will take longer to achieve (i.e. higher up the rev range) but you will still hit stock boost in the same time, possibly a bit earlier, than normal. Your graph is more accurate than you might think!

 

Now I need nurofen

 

-Ian

[Steve W]

Cheers Ian,

 

I can see why this 'playing-with-boost' thing gets contagious..

It's intriguing - even if it's a bit hit-and-miss.

 

BTW, I've entered my 'Boost Map Pic' in an UNDER 5's

Play School competition.......

 

Should be in with a chance . . ? ?

 

Fat S.