Corleone

Today I drove my Link2 equipped 951 and logged som runs. I have Afr about 12 for now, I´m just about in the beginning of mapping.

I have 72 lbs injectors, 3 bar fp and my logg showed a duty cycle of 75 %, how much power can it be?

billgot

alot!

Duke

Depends on the BSFC-value for your engine but at least around 450bhp according to a injector manufacturer's formula. And those are all very low on the hp-estimates vs fuel consumption.

Corleone

Ok thanks! Sounds very much to me but promising. I´m continue with my mapping and we will see... I have just put in my exhaust temp and soon I will know where the limit is.

Duke

What boost level do you run?

BTW I remember wanting to know more about your engine, but I don't think a phonecall would be sufficiant, I need to see that car in first person!

rage2

I ran out of injectors (72lb, 3bar FPR) at 450whp level. 100% duty cycle. 460whp ran a little lean up top.

I'm using 1000cc's now.

Laust Pedersen

You should be able to use this table to get an estimate. 72 lb/hr * 75% = 54 lb/hr -> 393 Crank HP * 85% = 334 WHP

Bengt Sweden

72 is 211%of stock 34 injectors. At 75% you would get 58% more than what is possible with stock or 440 to 470 whp depending on how rich you run. According to rage this is more than what he has experienced. Perhaps there is a difference in BSFC or the rating on the injectors is not correct.
Congratulations anyway!

BB

Duke

BTW TonyG put down around 400 whp with 72 lb/hr at 2.5 bar fuel pressure.

Corleone

Duke!
I run 20 psi down to 18 at 6700 rpm. My plan is to rev 7000, I do it now to but with less boost. For now my fuel is on the safe side. Soon I will map my car with my friend "Nille" at go a bit leaner and maybe up in ignition. My ignition right now is 23 degrees up to 20 psi. The car runs well and feels pretty fast!

Duke

Laust I find those kind of tables pretty much useless for our cars.
The reality has shown numerours times that you don't need 72 lb/hr injectors to reach 330 whp at decent duty cycles.

Heck, using those formulas for a stock engine shows 100% duty cycle is needed to produce 247hp, which I believe Porsche would not accept.

tazman

Rage if I remember correctly you don't use a rising rate FPR do you?

boosted951

This may be a lame question, but what is the max HP you can attain from the stock injectors? I am pushing 290 at the wheels with stock injectors/stock FPR....I am also running lean up top at 16psi....I poosted my dyno sheet with A/F ratio on another thread if anyone wants to see it.... I know I am due for new injectors, but just wanted to see what the max was... I do have a Apexi S-AFC to tune the air fuel ratio.....

B951S

23 degrees at 20psi, is that with race gas?? That's a hell of an advance for 20psi. Must be that big *** intercooler your running. I am running from 18 up to 26 at 20psi using water / meth. Is yours mapped at 23 degrees all the way through the 800 row though or do you build from a lower timing value at mid range to 23 degrees at red line??

Also, how do you like your link 2? Are you using closed loop knock?

THanks!

TurboTommy

I think there are a lot of inconsistancies when it comes to injectors.
If you remember awhile back Dfastest car was making way up the 400's hp with 52lb injectors. Based upon all the supposed info, how would that be possible?
Even within a certain rating, there is variance between sets of injectors and it's not even close to being accurate in calculating hp. Also, some injectors are over rated and some are under rated; sad but true. That's why a good vendor will flow match a set of 4 for you.
Wasn't there a thread awhile back on differences between types/brands of injectors (I think Danno was involved with the explanation).