Boosted MIVEC

spetz · Post by **spetz** » Tue Jan 04, 2005 12:52 am

How much boost can the 6A12 MIVEC handle with the standard internals and standard compression ratio?
And how much boost could the standard injectors handle?

And, do the 6A12TT injectors fit directly into the MIVEC fuel rail? What is their cc?

THanks guys

G_A_V · Post by **G_A_V** » Tue Jan 04, 2005 12:14 pm

6-7 psi is reccomended on standard internals with standard compression ratio, but i think your still pushing your luck even at boost that low without strengthening the internals

FTO338 · Post by **FTO338** » Tue Jan 04, 2005 12:25 pm

Scracy had ran his on 7-8psi for few yrs now, & have no problem with the standard internal.

Mikey had run 10psi with standard internal before, but now its a different story

spetz · Post by **spetz** » Wed Jan 05, 2005 8:39 am

What do you mean it's a different story????

What is the real weakness, the internals or the high compression?

I thought being such a high revving engine internals would be fragile to boost, and of course the compression wouldn't ever help either

I am thinking (if I can at all) run about 4-5 psi boost standard, and maybe have a switch for high boost at about 8-9 psi but that's a big if as I do not want a damaged engine

FTO338 · Post by **FTO338** » Wed Jan 05, 2005 9:48 am

spetz wrote:What do you mean it's a different story????

His got a complete different setup now, which allow him to run much higher boost.

If you want to know more then you have to send him a email as he doesn't like ppl talk about his setup at the moment.

MarkFTO · Post by **MarkFTO** » Thu Jan 06, 2005 8:13 am

My turbo GPX has been running a held 5.5psi of boost for 6months or so now. It had previously been running 7psi held for some time too but i decided to lower it for safety.

Running 5.5psi i can get up to about 80% injector duty on larger 275cc injectors, standards will not cope with forced induction as they are just too small.

Hope that helps.

//\\//\\ark

spetz · Post by **spetz** » Thu Jan 06, 2005 11:23 am

Where did you source the 275cc injectors from?
Are you running stock compression ratio?
What size exhaust do you have?
Single/twin turbo? What size turbo/s and when does it spool?
What engine management do you have?
And, the final question, those 5.5psi of boost, what do they do? How much better? Does it push you into the seat? Does it break traction???

Thanks

MarkFTO · Post by **MarkFTO** » Fri Jan 07, 2005 7:22 am

spetz wrote:Where did you source the 275cc injectors from?

We have only managed to source 2 sets of these from Japan at the moment. Ive not yet managed to get any from other mitsubishi here in the UK.

Are you running stock compression ratio?

yes

What size exhaust do you have?

the car is now running a 2.5" titanium system with no cat and a single silencer.

Single/twin turbo? What size turbo/s and when does it spool?

It runs a single TD04 turbo, no need for a large turbo as boost levels will always be very low. Full boost by 3200-3500rpm

What engine management do you have?

Its running an emanage piggyback ecu, very easy to use unit. Could do with a few more features but for the money it can't be faulted.

And, the final question, those 5.5psi of boost, what do they do? How much better? Does it push you into the seat? Does it break traction???

Thanks

its a tip and it handles the extra power very well indeed. We have managed a 14second 1/4mile @101mph which is good as you can't really launch a tip too hard. GPS verified 167mph top speed too

I love it, intention was to sell it but i would ideally like to keep it. Its currently shared between myself and Brian, (salatius on here, well the neame issomething like that) and im sure he will agree its how the fto should have been from the factory.

//\\//\\ark

spetz · Post by **spetz** » Fri Jan 07, 2005 11:56 am

If you are only hitting full boost by 3500 then there is something wrong as with such a high compression ratio and such a tiny turbo from 2 litre's I would expect you to be spooling from a bit over idle?

I was thinking of using a T28 or so...

Are you only feeding the turbo from one back of cylinders??
Or maybe due to such low boost on an interal wastegate it is too laggy?

Even 4G93's spool it at half that rpm with less cubes and less compression

how many kw at the wheels did you get???
Any trouble's on the way there??

dannyboyau · Post by **dannyboyau** » Fri Jan 07, 2005 1:27 pm

for your injectors you are better to use the ones from the 6A13 TT as they are almost identical, and fit with no modification needed. the only differance is the 6A13's are 390 cc

salacious · Post by **salacious** » Sat Jan 08, 2005 1:11 am

spetz wrote:If you are only hitting full boost by 3500 then there is something wrong as with such a high compression ratio and such a tiny turbo from 2 litre's I would expect you to be spooling from a bit over idle?

I was thinking of using a T28 or so...

Are you only feeding the turbo from one back of cylinders??
Or maybe due to such low boost on an interal wastegate it is too laggy?

Even 4G93's spool it at half that rpm with less cubes and less compression

how many kw at the wheels did you get???
Any trouble's on the way there??

I'll let Mark answer the rest of the questions but the turbo is feed by both banks. The car has been RR'd at 214bhp ATW (I think that is about 160KW) and this is on a tiptronic

spetz · Post by **spetz** » Sat Jan 08, 2005 12:11 pm

Are those 390cc same as GSR injectors?
I don't want a rough idle either...

214bhp is actually very impressive from just 5.5psi.

How does the turbo maintain such low pressure though?

And how is the ECU with piggyback tuned with boost and MIVEC???

dannyboyau · Post by **dannyboyau** » Sat Jan 08, 2005 11:52 pm

spetz wrote:Are those 390cc same as GSR injectors?

can't be certain about the GSR injectors as i haven't seen any.

But i believe the GSR ones might be low impedence.

the FTO is high impedence injectors same as the 6A13TT

spetz wrote: I don't want a rough idle either...

once you start making major changes like turbo you will reqiure aftermarket fuel mapping, which then should enable you to have a nice idle. untill you start getting up to around 700cc or higher injectors you dont really need to worry about idle, if you got a good tuner.

MarkFTO · Post by **MarkFTO** » Mon Jan 10, 2005 6:48 am

boost is currently only regulated using the actuator due to the low pressures required. All that is done to alter the boost is adjust the actuator. Id plan on fitting a boost controller and different actuator to allow me to run just 3psi for daily driving. I can't say i have ever felt it laggy, I havent looked at the boost vs rpm since i last mapped it either, however looking back at the logs i have positive boost by 2200 rpm which ramps to 5.5psi by 3200-3300rpm.

As Brian said we after my last mapping session we got 214bhp@wheels (estimated @262flywheel bhp) but i have no doubt i could get another few bhp from it with more time spent mapping, however i lent my wideband to a friend who managed to kill it

still waiting for a replacement.

If it was my own car i would probably lower compression and up the boost a little but i don't want to spend much more on her as my other fto is taking too much of my money already.