Mitsubishi EVO VIII (8)

godane79 SG

IF im not wrong, you are right...... turbo kicks in at bout 3500rpm

Seriously...wats with the piss sound? noticed tat even buses or trailers has those?

Ever notice a ferrari or a lambo has those?

BOV is to try to optimise your turbo and prevent it from turbo lag....

DoggieHowser SG

You get the peak torque at 3500rpm.

But the turbo begins spooling abt 500rpm earlier.

With the 9, you can see some noticeable gains from 2000rpm, and peak torque is at 3000rpm

You need a way to release the boost when you go off throttle. Stock turbocharged cars usually use a recirculating diverter valve. So you don't get a loud pssshhh sound.

Most guys change to a vent-to-air VTA blow off valve (BOV) which gives that sound. It mucks up the MAF sensor on stock Evos tho. And there are no gains... unlike what the other guy says.. it does not reduce turbo lag.

ceecookie SG

well or u can also increase the turbo bar to like 2.3 or so....but be warned, too high can blow the engine...
my uncle blown his Version 2 WRX's engine thrice when he raised the turbo bar too high.........

DoggieHowser SG

Holleeemuddderrrrofff

Want to mod oso must be smart about it.

Firstly, do you realize what kinds of stress you engine block has to endure to get a 2 bar boost!?? You would need to strengthen the whole block before you subject it to this kinds of abuse.

Secondly, most turbines have an ideal operating range. For a stock turbo, it is pointless to stress it to boost to 2 bar, because all you are doing is just compressing hotter and hotter air, not at all efficient at all (even without factoring the stress in the engine).

Haiz... sometimes I think people take modding lessons from shows like Legend of Speed, and wonder why things go wrong.

tailslide SG

funny, i tot it does? when the excess pressure inside the turbine is released, it is effectively prevented from counteracting the direction of spool rite? this means the effect on the inertia of the spooling is reduced, or minimized at least. or is the function of the BOV aimed solely at prolonging the longevity of ur turbine? Confused i'm a virtual noob with turbos.

DoggieHowser SG

turbocharged cars are fitted with a diverter valve, which is what releases the pressure. Replacing the DV with a Vent To Air BOV merely changes where the air is vented to. On Evos, switching to a VTA BOV tends to cause issues like stalling, messing yr MAF sensors etc...

dansplace SG

With the BOV, it feels that the whole structure of the car is under great stress when upshifting...

crufty SG

The factory dump valve or compressor bypass valve minimizes compressor surge as you described. A BOV is different in that instead of recirculating the air back into the intake, it is vented to the atmosphere. Neither system has any anti-lag properties by themselves.

For a car running on any fuel metering system other than MAF, running a BOV is not a problem. On a MAF-system such as the Evo however, you will get into a momentary rich condition since the air which has been vented is no longer in the same proportion as the injected fuel.

[email protected] SG

lets just say u were talking to a 14 year old kid who's well known on forums for being somewhat insane. Laughing

ceecookie SG

the turbocharger should be the TD-05 or so he told me....the turbo is stock...he bought second hand one so it has already been modified by its previous owner.New oil filter, racing clutch, upshift blinker etc
and yes i agree that engine will get hotter, one time when i was driving with him i saw the temp needle rising up to more than half of the gauge.i also heard form him that maintainence was expensive as he extensively raised turbo bar, and not to mention downshifting to red zone many time when he took me and my cousin for a spin..but i could not see the tacho as i always lost my balance as the boost was so strong.The engine's condition was worsening as it ages....finally a few yrs back he sold it to NZ racing school in Christchurch.

PS: Ditzy, im not insane......and btw im 15.....
and if ya all not believe me i give u his hp number and u verify with him... Mad

[email protected] SG

u think im ditzy? well done. i think he's not gonna be very happy with that.
meanwhile... Laughing

crufty SG

1) "the turbo is stock...he bought second hand one so it has already been modified by its previous owner." So is it a stock turbo or modified?

2) Boost pressure has nothing to do with oil filter, racing clutch, upshift blinker etc.

3) May I ask what boost gauge is he running? Maybe you can find a pic online and show us?

tailslide SG

ah, icic. so BOV is typically useless except make noise and attract attention?

crufty SG

It's not that it's useless insofar as the factory dump valve does the job without much fanfare, possibly due to emissions (noise). I've seen joggers literally leap off the pavement when a BOV unexpectedly goes off near them. The other possibility is that the stock dump valve spring pressure has weakend over time and the car is no longer on MAF as explained earlier...

ceecookie SG

1) the turbo is stock(TD-05) and the mods were like oil filter and things like in number 2.......he also added in a Blitz Blow Off Valve which i 4got to add in
Yes as u said that higher turbo bar will put more strain on the enigne, as a result he told me maintaining cost was high...he was right...when he brought me for a spin on the then 9yrs + WRX, i could smell burning smell from maybe the racing clutch after attempting 140km/h on the upp bukit timah rd that is now having the Linear Condo under construction.PS. When the WRX was ard 3-5 yrs old or so, he brought it to NS Highway and did 260km/h.....
2) yes i know....he just increase the turbo boost bar higher so it was ard 5.4 from 6.4 for 0-100km/h timing from the specs

3)Sure i try to get the pic or tell u the brand when i called him......

Edited: Yea i called him...he said the turbo boost gauge was modded one...then turbo boost was 1.25 or so he told me....sorry i made a mistake and made it 2+ bar... Embarassed

and sorry ditzy i tot u was the one who wrote it when [email protected] was the one..

by DoggieHowser
For a stock turbo, it is pointless to stress it to boost to 2 bar, because all you are doing is just compressing hotter and hotter air, not at all efficient at all

then wat abt the intercooler....u could program it to make more cool air at 2+ boost.

crufty SG

ceecookie...

I don't understand your posts. It seems that you're trying very hard to impress us with your knowledge or experiences. Nothing wrong with that in itself, but you should always verify the truth for yourself before posting something. Like you mention "programming an intercooler for 2+ (bar)", do you even know what an intercooler is? How can it be programmed?

To have productive dialogue, all parties must communicate based on a solid foundation of facts... perhaps it might be useful for you to do some research before posting further.

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