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What Hp Are Stock Injectore Good For?

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Posted

I have a 94 850 turbo and was wondering what hp the stock orange injectors are good for?

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Posted

Hello,

There is a great calculator located here:

http://www.witchhunter.com/injectorcalc1.php4

This site is full of resources reguarding injectors. Covers everything from injector size calculations to stock injector flow rates (listed by Bosch P/N). Using the calculator on the linked page, you should be able to plug in different HP numbers and find the injector flow to match (stock 850T injectors are roughly 310cc's @ 43.5 psi). Kind of a backwards calculation, but it works. It kind of goes against everyones "one HP for each cc" theory, as there's no way a 310cc injector will be sufficient for 310HP on a turbo engine. If that were the case, no one would bother upgrading to whites or blues :).

Good luck,

Joe

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or . . your injectors could be sized for each turbo (used as a minimum could always go bigger) -

15G - Orange

16T - Orange

18T - Whites

19T - Whites

K24 - Blues/Green

16G - Blues/Green

20G - Green/550 cc RC Eng.

GT30R/3071R - 550 cc RC Eng.

GT42R - Red (J/K!)

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Posted

or . . your injectors could be sized for each turbo (used as a minimum could always go bigger) -

15G - Orange

16T - Orange

18T - Whites

19T - Whites

K24 - Blues/Green

16G - Blues/Green

20G - Green/550 cc RC Eng.

GT30R/3071R - 550 cc RC Eng.

GT42R - Red (J/K!)

and the 13t comes with reds... why did they bother making an injector only +5cc more than the orange?

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Posted

It kind of goes against everyones "one HP for each cc" theory, as there's no way a 310cc injector will be sufficient for 310HP on a turbo engine. If that were the case, no one would bother upgrading to whites or blues :).

not entirely true. people are often upgrading for the extra margain of safety, or so that the injectors arent running at 100% duty cycle.

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Posted

not entirely true. people are often upgrading for the extra margain of safety, or so that the injectors arent running at 100% duty cycle.

Hello,

Absolutely, I agree with you. I have a set of blues that I intend to run with my 15G and (soon) 12 psi tune on my 2000 S70. The stock oranges likely would have been fine for such a mild application, but I like the security of a little more fuel potential if needed. I figure, Volvo used the whites and blues on the HPT cars for a reason. If the oranges were enough for the HPT cars as well, they could have saved lots of money and went with a single injector rating.

I still am not 100% sold on the "one for one" theory though, as every injector calculator I have used (and I've used several) has indicated that I need a 395cc injector, not the 315cc units that I currently have. That is with the aim of only 230-235 flywheel hp, nothing extreme. They could all be wrong I suppose, but they are taken from very reputable sources and all give the same result.

Thanks,

Joe

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Posted

Hello,

There is a great calculator located here:

http://www.witchhunter.com/injectorcalc1.php4

This site is full of resources reguarding injectors. Covers everything from injector size calculations to stock injector flow rates (listed by Bosch P/N). Using the calculator on the linked page, you should be able to plug in different HP numbers and find the injector flow to match (stock 850T injectors are roughly 310cc's @ 43.5 psi). Kind of a backwards calculation, but it works. It kind of goes against everyones "one HP for each cc" theory, as there's no way a 310cc injector will be sufficient for 310HP on a turbo engine. If that were the case, no one would bother upgrading to whites or blues :).

Good luck,

Joe

Has anyone actually tried these online calculators with a stock car? Let's plug the numbers in for a stock 850 R manual, which makes 250 hp with white 350 cc injectors:

Power (flywheel) = 250 hp

Number of Injectors = 5

B.S.F.C. = 0.60 - 0.65 (as specified in the notes for a turbo engine)

Max Duty Cycle = 80%

Hit calculate and it says you need injectors which flow between 394 cc and 427 cc/min.

So, according to this calculation, the 350 cc injectors supplied by Volvo would not be anywhere near big enough to make 250 hp, yet we all know that it can make 250 hp all day long!!!

Would anybody like to provide some clues as to why this formula fails for a stock 850R? And if it fails for a stock car, why should anybody consider using it as a guide for modded cars?

I should point out that the above was of course done with two seperate calculations. One with BSFC = 0.60 and another calculation with BSFC = 0.65 which gave 394 cc/min and 427 cc/min respectively.

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Posted

=================================================================================

OK, now lets throw another spanner in the works... :)

We all know that all the well know tuners can make 275 hp on a stock 850 T5 with just a remap. We also know that a stock 850 T5 has orange 315 cc injectors.

So, lets plug some numbers in to see what is required to get 315 cc if you want 275 hp:

Max Power = 275 hp

Injectors = 5

B.S.F.C. = 0.6

Max Duty cycle = 110%

Hit calculate and you get: Injectors required = 315 cc

Wow!!! So, according to this injector calculator, RICA, MTE etc would need to run the injectors at 110% duty cycle to get 275 hp from just a remap. Now, unless I'm mistaken, 110% IDC is impossible!!!

So, let's for the sake of argument bring the duty cycle back down to 80%, since responsible tuners MTE or RICA would never dream of overdriving injectors right? :)

OK, so the new numbers are:

Max Power = 275 hp

Injectors = 5

B.S.F.C. = 0.436

Max Duty cycle = 80%

Injectors reqired = 315 cc

Tada!!! 275 hp can be reached at 80% duty cycle using 315 cc injectors, if the BSFC = 0.436

With me so far? It looks like the BSFC recommended values are wrong since this online calculator states that BSFC should be 0.60-0.65 for turbo engines. Let's therefore assume 0.436 as the new correct BSFC and see if it's possible to get 300 hp on 315 cc injectors...

Max Power = 300 hp

Injectors = 5

B.S.F.C. = 0.436

Max Duty cycle = 87%

Injectors required = 316 cc, assuming BSFC = 0.436

Voila! :)

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Posted

K thanks a lot guys. The reason i asked is because i have a 17 psi tune for my 15g and was wondering if it would be worthwhile to get whites.

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K thanks a lot guys. The reason i asked is because i have a 17 psi tune for my 15g and was wondering if it would be worthwhile to get whites.

Upgrading to a 18/19T in the future ? IF yes, then grab some whites.

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Posted

=================================================================================

Tada!!! 275 hp can be reached at 80% duty cycle using 315 cc injectors, if the BSFC = 0.436

With me so far? It looks like the BSFC recommended values are wrong since this online calculator states that BSFC should be 0.60-0.65 for turbo engines. Let's therefore assume 0.436 as the new correct BSFC and see if it's possible to get 300 hp on 315 cc injectors...

Hello,

Not sure if that post was serious or just sarcasm, but here goes :D. Every calculator that I have found recommends a minimum of .60 for BSFC on a turbocharged engine, with .65 being ideal. It's not an error on the afore-mentioned site, just the facts. I am not arguing that oranges aren't good for anything more than stock, but I do think the answer lies somewhere in the middle. I agree that the calculator shows that stock oranges are not even sufficient for the engine they came with :). With a 17 psi tune though, I'd feel very insecure about running orange's if it were me...

Joe

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Posted

Hello,

Not sure if that post was serious or just sarcasm, but here goes :D. Every calculator that I have found recommends a minimum of .60 for BSFC on a turbocharged engine, with .65 being ideal. It's not an error on the afore-mentioned site, just the facts. I am not arguing that oranges aren't good for anything more than stock, but I do think the answer lies somewhere in the middle. I agree that the calculator shows that stock oranges are not even sufficient for the engine they came with :). With a 17 psi tune though, I'd feel very insecure about running orange's if it were me...

Joe

It was a serious post, done in a fun way! :)

The main point was that if this online injector calculator is showing that stock orange/white injectors are insufficient for a stock car (when we clearly know that they are sufficient), what use is the online calculator? The online calculator must work for stock and modified cars, otherwise it's useless and just misleads people.

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Posted

if there is someone you should listen to, its probably ^this^ person, lol.

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Posted

I love Turbotuner, he makes learning so much fun! And he knows his stuff, y'all.

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