[Chase2000gt]

If power brakes work under vaccum, what happens under boost?

 

[Bitter]

its vacum assist, your car can stop with out the vacum, but ive been wondering this too. tho how often do you use your brakes at full boost? :nuts:

 

[Chase2000gt]

The reason I am asking is because the GTS manifold is controlled partly by vacuum. And under boost, there wouldnt be any vaccum to pull it open.

Ive been thinking about it, and you should be able to control the vacuum solinoid with a MSD window switch.

 

[Bitter]

hmm i saw a Ripped GTS at btn5, the first ripped GTS. the mivec on it worked....

ya a window switch would work great tho, and then you could control the rpm at which mivec engaged

 

[Chase2000gt]

hmm i saw a Ripped GTS at btn5, the first ripped GTS. the mivec on it worked....

ya a window switch would work great tho, and then you could control the rpm at which mivec engaged

Mivec is variable valve timing. Where talking about varible length intak runners.

Are you sure it worked on the GTS though? Now I just want to know how?

 

[Bitter]

i know mivec is the intake runner, with the reed valves.

ask ripp?

that first line is kinda hard to understand... :ugh:

 

[Chase2000gt]

i know mivec is the intake runner, with the reed valves.

ask ripp?

that first line is kinda hard to understand... :ugh:

Are you sure? I always thought mivec=vtech? Variable valve timing

 

[NAPALM]

1)

Your brake booster vacuum line has a one way check-valve built into it. It allows vacuum in one direction(towards the engine) and then closes shut if air is forced towards the booster.

If the check-valve is working properly your brakes will feel firm and will require more foot pressure to stop the car when you step on them under boost(basically feels like the car is off). If the check valve is not working properly(letting pressure into the brake booster) the brake pedal willl feel rock solid and your brakes will require an emense amount of foot pressure to stop the car.

2)

MIVEC is variable valve timing technology. It does exactly that; varies the timing of the valves while you drive. Has nothing to do with variable induction(manifold runners) systems.

 

[Bitter]

Are you sure? I always thought mivec=vtech? Variable valve timing

nope mivec is a set of reed valves in the GTS manifold that change the lenght of the intake runners dependent on rpm and throttle. higher rpms the valves give the air a shorter path so the engine can breathe better. at lower rpms a longer path for more torque. well thats come to be my understanding of it. lets see what google says!

http://www.mitsubishi-motors.com/corporate/about_us/technology/performance/e/mivec.html

hmm google disagrees...maybe japenese mivec and north american mivec are different? :ugh:


well that shows how much i know :nuts: sorry.

 

[KRZY1]

I knwo that people on SRTforums that had done track events had complained that sometimes when on the brakes during boost or just after letting off they were saying that the brake didnt function properly...

 

[Chase2000gt]

1)


If the check-valve is working properly your brakes will feel firm and will require more foot pressure to stop the car when you step on them under boost(basically feels like the car is off). If the check valve is not working properly(letting pressure into the brake booster) the brake pedal willl feel rock solid and your brakes will require an emense amount of foot pressure to stop the car.

With that said, The runners probally wouldnt switch under boost, even if the solinoid was activated.

 

[Bitter]

With that said, The runners probally wouldnt switch under boost, even if the solinoid was activated.

your probably right, rig up a magnetic solonoid on an rpm window switch. a servo may even work. but a solonoid would probably be easier to fit and work faster and more reliably

 

[Chase2000gt]

your probably right, rig up a magnetic solonoid on an rpm window switch. a servo may even work. but a solonoid would probably be easier to fit and work faster and more reliably

I thought about a servo, but speed is definatly an issue.

 

[NAPALM]

FYI
MIVEC = Mitsubishi Innovative Valve-timing-and-lift Electronic Control

:twothumb:

KRZY; Yup thats normal. I went to hit the brakes a few times quickly after letting off from almost WOT(@ 10PSI) and the brakes were very hard for a brief moment. Its kinda scarey at first. But if you are aware that its going to happen its not too bad.

Chase; Im not sure how the GTS mani works as far as that goes. I know my MR2 had a similar system; T-VIS(Toyota-Variable induction system). It basically had 8intake runnners(4 cyl engine, 2 for each cyl) and there was butterflys keeping one runner of each of the pairs of runners closed until about 4-5K rpm. Under WOT they would ALL open up, I think this system was electronically controlled. BUt im not sure...............

 

[Chase2000gt]

I just got my GTS mani today. There is a soliniod that lets vaccum through, that vacuum pulls the flap open and block off a set of runners.

 

[NAPALM]

Doesnt make sense....................:scratch:

Usually the idea is to open up the runners at close-to WOT to allow more air to flow into the combustion chamber........

 

[Bitter]

so theres one noid (lazy abbrev) for each valve? or one noid for all the valves?

 

[Chase2000gt]

Doesnt make sense....................:scratch:

Usually the idea is to open up the runners at close-to WOT to allow more air to flow into the combustion chamber........

There is a set of long and a set of short runners. Its changes from short to long, or long to short @ a certain RPM. Ill take a picture or two

 

[Bitter]

Doesnt make sense....................:scratch:

Usually the idea is to open up the runners at close-to WOT to allow more air to flow into the combustion chamber........

yea so it can breath better at high rpms but still have tq at lower rpms.

long runners make torque and short runners boost well and make topend but suck for making torque just like long runners dont breath well at high rpms

sorry im like talking in circles bad mood and a tiring day kinda.

 

[NAPALM]

COOL! :fawk: