azmi951

So with a k27-6 and 3" exhaust running 18 psi would I need a map/maf and injectors?

TonyG

azmi951

With a K27/6 running 18psi.. you need larger injectors. The exhaust is irrelevant.

You can run higher fuel pressure instead of larger injectors... but it's a poor way to go when compared to using the proper sized injectors.

You should do a MAP/MAF as well. I prefer the MAF by far to the MAP setup on a street car. It's easier to dial in.

Good luck,

TonyG

NZ951

Tony, have you used a MAP setup? They are seriously very easy to tune, and are more accurate than MAF...

TonyG

NZ951

I don't even want to get into this discussion... but suffice to say, I have experience with MAP setups.

I prefer the MAF.


TonyG

NZ951

Ok, I was just curious as to why thats all. As most all aftermarket standalones use MAP, I was curious about the advantages of MAF over MAP for you. Though there are many threads on that generally...

jsonnen

I thought alot of people were having off idle stumbling issues with the MAP set-up?

NZ951

Hmm not sure about idle. I know some were having issues with stumbling with the interceptor MAP setup. The standalone MAP version is flawless in operation. It does what its supposed to do. I imagine there was a tuning issue with those getting stumbling. Perhaps this is what Tony is referring to.

Black Arrow

TonyG

When buying new injectors, what`s best to buy; To large injectors that also can be used for later upgrades, or the perfekt match for the setup you have at the moment?
And for 400+DIN HP (vitesse stage 2) what kind would you prefer? Looking at the siemens 55lb / 72lb vs bosch 52lb..(LindseyRacing)

MitchB

I just pulled my stock 26/6 out. I'm going to have it rebuilt while everything is apart, but not sure what to do....
Majestic Turbo is close to home and can rebuild it stock for around $350.00 but can upgrade it to a 27/6 for an additional $350.00. If - I HAVE to go to 55 lb injectors and a MAF/MAP intake to run this (the K 27) then it will put me over budget (there's lots to be fixed/done).
Should I maybe go to a 26/8 with chips and just wait till next time...?
Appreciate the opinions - great thread.
M

TonyG

tma§951

The smaller the injector, the easier they will be to get dialed in.

If you're looking for 400RWHP (approx 480Bhp), you'll need the 72lbs injectors to keep the fuel pressure stock (which is what I prefer to do).


TonyG

slim_boy_fat

I would say go for the 27 right off the bat, then do the other upgrades in say 6months, what the point in doing the turbo in 2 stages. Either that or get another credit card!!!!!!

TonyG

MitchB

You can put the K27/6 turbo in and run the car as-is at stock boost levels for now. The get the rest of the stuff (MAF/Chips/Injectors/Wastegate/Boost Controller) as money and time permit in the future. This by far better than a K26/8 setup.

You'll need an adapter fabricated up to go between the turbo inlet of the K27 (Which is 2.75") and the opening of the black rubber "J" boot (which is smaller than 2.75"). You'll cut the J boot back until it is 2.75", then use a sleeve as an adapter between the two. No big deal.

I'd have an a/f ratio gauge to make sure you aren't going lean. I'd also have a boost gauge so you can monitior your boost level accurately (the stock boost gauge isn't worth the plastic it's made out of)

Even at stock boost levels... you'll notice that you have much better top end with the K27/6 for sure.


TonyG

J Chen

Speaking of which Tony, why do you think GURU advocates
the use of 3 bar FPR with his chip set ? Has it got to do with
keeping the fuel better atomise when running with bigger
injectors ?

TonyG

J Chen

"why do you think GURU advocates
the use of 3 bar FPR with his chip set ? Has it got to do with
keeping the fuel better atomise when running with bigger
injectors ?"

That's nonsense. The factory engineers, and we're talking about degreed, certified, and licensed engineers here, know what they're going. You can rest assured that this issue was studied at length by Bosch and Porsche.

The fact is simple... you can get more fuel out of an injector by raising the fuel pressure. As you raise the fuel pressure, you will lower the volume available from the pump. But... it's cheaper to raise fuel pressure than it is to require new injectors.

Considering this, it's easy to see why the larger FPR is required with his chips.

Is it the right way? No. Is it the cheap way? Yes. Will a larger FPR work? Probably (to an extent)

The right way is to use the proper sized injectors.

The economics of selling chip kits is another issue.

TonyG

hosrom_951

So, what size injectors would be best for a K27/6, to keep stock boost (for now) then maybe hitting 18 in the future to gain the 330~345whp? 55lbs/hr?