Manual boost Controller

[nickliv]

Why do I want one?
What benefits will I get?
How do I set one up?
Should I get one?

1993 900 T16S Otherwise standard.

[Jezzadee]

"Why do I want one?
What benefits will I get?
How do I set one up?
Should I get one?"

Because you want to go faster
40+ BHP and going faster
Um...
No

Because, IMO, you already have a piece of equipment that was very advanced for its time, does the job of an MBC but also adds a safety net. The APC. MBC's are risky. I happen to run one with no problems, but mine is an ex-LPT and has no APC. The APC can be tweaked easily using directions on here and on www.900aero.com . This will give you the power of an MBC while keeping the safety element.

[garry]

yes , you have 2 options...

MBC

or

APC


MBC may seem the quickest, cheapest and most effective way to go but to set it up right requires a lot of testing with performance equipment AND regular checks.


APC may seem to be a bit of a pain to initially set up so that you boost well.... but once done it will constantly recallibrate itself to ensure that your engine and gearbox survive punishing driving styles. As the MBC but fully automatic assesment and adjustment all the time.

[niko]

I recently purchase an old electronic boost controller: HKS EVC IV. I can affirm that with any mitsubishi's turbo, it's incredible !!! the problem with mitsu's is that at high rpm, the pressure drop is too much, thing that don't happen with the garett (it seems that there is more complain about boost drop with mitsu owner rather than garett...)

So my advice: buy an old electronic boost controller on ebay. With mitsu turbo, it will work very good because: the mitsu will spool up very fast, and the EBC will hold the pressure at high rpm, and finely regulate the pressure: no boost spike. It seems that the MBC work great with garett but not so much with mitsu. Moreover, i think that with an EBC you don't need a forge wastegate or something like that.
PS: i recently bought the forge wastegate with the strongest spring available:17psi. Even with this actuator, the pressure was droping too much at high rpm...1.2bar down to 0.7bar !!!!! The only way to maintain pressure is to shorten the actuator arm, but the boost creep is near...

Since i bought my car, and had done a lot of modifications, there is three modifications that had change the face of the car: 1/ installation of an tweaken APC to the car (originally LPT)
2/ installation of the electronic boost controller
3/ agressive ignition map

BUT take care with the boost pressure...because with a electronic device that can hold 1.6bar until 6000rpm, without more fuel and a lot of modifications, your will kill your engine...

PS: with the EBC, 15° at boost and 0.8bar max with stock injectors, the car don't run lean, and is very strong at the red line. A car "a la Eric Van Spelde..."

[Johann F]

Niko - what's your agressive ignition map? - I'm running 20deg at idle and 11 deg on full boost ( 1 bar ish) with a late vacuum actuator. I have tried more retard but I get less power and am reluctant to try less retard with the stock Lucas injection.

[niko]

i told it on my post: try 15° at boost with 0.8bar. You will hear a different sound coming from the engine. Even try 17° with 0.7bar.

[niko]

One day, just after trying a new ignition setup, i forgot to reinstall the vacuum hose on the capsule. So i was at 25° all the range of boost. But the tweaked APC was in place, with max boost if no knock set at 1.2bar. I ran like that two days. Naturally the car wasn't running like the day before (especially in term of boost:0.8 bax max - sometimes a peak at 1bar, but the gear after, the engine was not able to give again 1bar) but the apc was doing is job and the car was really different: the sound at high rpm was very furious, the engine was aggressive, not an overtorque engine at middle range, but an engine that give power at high rpm. Like other 16V.
This was not enough. But the car was really different, and with less lag off boost.

So if you have a good APC, safe enough to do some test, naturally with a low base boost (0.4bar), why not trying a new ignition map ?

[Johann F]

OK I'll give it a try - I made an external adjuster for my retard limit so reducing the amount will be quite simple.

[Saab-Daniel]

Johann, how did you do that?
And how do you guys mod your ignition, so you can obtain a higher degree when of boost, while still getting retard when at boost?
Daniel.

[Johann F]

Drilled out the stop tab and replaced it with a small bolt. Ground the bolt head into a cam shape so that turning it changes the retard gap. Foe best retard action you must use a late dist vac unit as found on the LPT - they have a more progressive action.

[Saab-Daniel]

Hmm, Thanks for the answer Johann, but it seems to me that the difference in language is letting me down here... Not sure quite what you mean... But I'll just have to get a capsule from an LPT if I can find one, otherwise just one of a normal 8v turbo, and then I'll return if I have any questions...
Thanks man
Daniel.

[Jezzadee]

English is my native language and I still don't understand all that . The words I can follow but the general meaning somehow goes over my head. And I've got an LPT. Don't know if this would help at all.

http://www.900aero.com/phpBB2/viewtopic.php?t=358