Make sure you have the right injectors...

[HONDA GHANDI]

Its easy to check resistance with an ohm meter, make sure you have the correct style (Peak hold/saturated) injectors in your car.

With Low impedance injectors you need a resistor pack to bring the system amperage down to a managable level for the ECU. Otherwise.... BOOM!

http://www.hondata.com/downloads/injector-testing.mov

[Kwando]

ouch that sucks! how often does that happen?

[HONDA GHANDI]

More often than you think. That brings up another reason to be very careful whn you buy a used or EBAY ECU. I used to buy them on EBAY for Hondata setups. About 1 in 10 was smoked. I could usually put a new injector driver in it but sometimes it would smoke the board too bad to repair.

[ghost_masterCL]

damn, better not mess around if you dont' konw what you're doing.

speaking of injectors, any suggestions on a good injector sizing calculator? One that takes amoutn of boost as a parameter instead of "desired horsepower" preferably.

[HONDA GHANDI]

This is a crude but good one. It also helps you with BSFC if you use that calculation for anything.

http://www.iroczone.com/calcs/injectorsize.htm

[ghost_masterCL]

cool, but what I don't get is it has the diffferent BSFC for na, turbo and SCed, but if it's going to be turboed, and wasn't fromt eh factory, which one should I choose?

[HONDA GHANDI]

The BSFC is different for every car but those are just some basic numbers that your car should fit into. Like I said it is crude. Some people (especially at this altitude) are running in the high .5* with turbo cars and some well into the .6* and higher. So just take this calculator with a grain of salt and remember it will be different at this altitude. You can get away with less injector usually up here.

[ghost_masterCL]

hmm, what about this one: http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=5800&Tamb=21&Bore=86&Stroke=86&nCyl=6&RPM=6000&VE=82&Boost=9&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=.59&AFR=12.5&maxInjectorDutyCycle=85

that's with my settings, 245cc injectors at 85% duty cycle seems kinda small for 9psi of boost.

[HONDA GHANDI]

That one seems pretty complicated. You may be missing an input somewhere.

[Weston-work]

hmm, what about this one: http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml?FeetASL=5800&Tamb=21&Bore=86&Stroke=86&nCyl=6&RPM=6000&VE=82&Boost=9&Ec=75&Eic=70&PdropIC=0.5&TambIC=21&wiPercentMethanol=50&wiRate=100&wiTemp=21&SFC=.59&AFR=12.5&maxInjectorDutyCycle=85

that's with my settings, 245cc injectors at 85% duty cycle seems kinda small for 9psi of boost.

That's a pretty cool calc since it maps it to a compressor map and stuff. As for the injector size, it seems a bit on the low side, but may be in the ballpark for me. I'll have to compare it to my actual injector duty cycles when I get home...

[Weston]

If I set the volumetric efficiency to 95%, the injector numbers seem to come pretty close to mine when I set the "Max Injector Duty Cycle" to my actual duty cycle at that RPM, relative boost pressure, and fuel ratio. I would say that it's erroring a bit on the low side, but if you set the max duty cycle to 85%, it would seem that you're fine. Of course, this does not account for fuel pressure, so ymmv.

[ghost_masterCL]

If I set the volumetric efficiency to 95%, the injector numbers seem to come pretty close to mine when I set the "Max Injector Duty Cycle" to my actual duty cycle at that RPM, relative boost pressure, and fuel ratio. I would say that it's erroring a bit on the low side, but if you set the max duty cycle to 85%, it would seem that you're fine. Of course, this does not account for fuel pressure, so ymmv.

yeah, I was wondering how it calculated that without any sort of fuel pressure setting. That is the calc I used to size the turbo I plan on using, but since it doesn't actually have that specific turbo's map you can just get the LBM air flow and boost ratio from the bottom left column.

for my settings with 95% volumetric effieceincy, I get 285 cc/m so I should probably opt for around 300 cc injectors to be safe?

also, does the .5 psi pressure drop from the intercooler seem reasonable? that's onf of a few things I have no idea about, also I figure a mid to high 12's AFR seems like a good tune for 9 psi.

[boostedEG]

300cc injectors sounds very small to me. i know your motor is a 3.0 v6, and i am not very familiar with those, but B-series vtec motors have 240cc stock IIRC, and i was under the mipression they ran somewhere around 90% duty cycle, so they cant upport very much more HP.

im not aware of any dowside to getting bigger injectors than you need (within reason) other than its a little bit harder to tune on real big injectors (1000-1600cc). if there are other reasons please fill me in. if not then just get a set of 500-600cc injectors. even if its more than you need it will leave you room to grow incase you ever want to turn up the boost a bit.

on another note whats wrong with a calculator that bases stuff off of expected HP? there are so many variances with turbos that effect HP that it seems it would be way more difficult and innacurate to measure it based off of how much boost you want to run.

[john]

Damn - I'm gonna need 1000cc parts if ever upgrade...

[Weston]

but B-series vtec motors have 240cc stock IIRC, and i was under the mipression they ran somewhere around 90% duty cycle, so they cant upport very much more HP.

Yup. For a B18C1, it's actually about 95% duty cycle at it's revlimiter (8200 RPM), at sea level.

[ghost_masterCL]

300cc injectors sounds very small to me. i know your motor is a 3.0 v6, and i am not very familiar with those, but B-series vtec motors have 240cc stock IIRC, and i was under the mipression they ran somewhere around 90% duty cycle, so they cant upport very much more HP.

im not aware of any dowside to getting bigger injectors than you need (within reason) other than its a little bit harder to tune on real big injectors (1000-1600cc). if there are other reasons please fill me in. if not then just get a set of 500-600cc injectors. even if its more than you need it will leave you room to grow incase you ever want to turn up the boost a bit.

on another note whats wrong with a calculator that bases stuff off of expected HP? there are so many variances with turbos that effect HP that it seems it would be way more difficult and innacurate to measure it based off of how much boost you want to run.

well, there is a guy with a supercharger running 370cc s2k injectors at around 9 psi on a 3.2L J series engine, but he is at sea level. Also someone at sea lvel runnign a GT35R turbo at 6.5 psi with 270cc (stock) injectors on the same 3.2L engine.

I figure if I'm running 9psi up ghere that woudl be like runing the 6psi at sea level, so if 270cc is enough for him then 300 should be good enough for me.

also, the reason I wanted something based on PSI and not HP is becuase honestly I don't care what my HP output is, I just want whatever I can get out of 9psi which is fairly safe on a stock block.

[boostedEG]

well, there is a guy with a supercharger running 370cc s2k injectors at around 9 psi on a 3.2L J series engine, but he is at sea level. Also someone at sea lvel runnign a GT35R turbo at 6.5 psi with 270cc (stock) injectors on the same 3.2L engine.

I figure if I'm running 9psi up ghere that woudl be like runing the 6psi at sea level, so if 270cc is enough for him then 300 should be good enough for me.

stock is 270cc and you think 300cc will be enough? i dont believe it. the only way those injectors are gonna feed enough fuel is if you are running 80psi of fuel pressure, and while that could work its not the "right" way to do things. get big enough injectors that you can run stock fuel pressure.


also, the reason I wanted something based on PSI and not HP is becuase honestly I don't care what my HP output is, I just want whatever I can get out of 9psi which is fairly safe on a stock block.


yeah but 9 psi on a T88 could make 450-500hp and blow your motor, while 9 psi on a little T3 might only make 250HP and be perfectly safe. you cant just go off of boost pressure, as there are so many variances with turbo sizing and efficiency rates. thats why you usually shoot for "x" amount of horsepower, and to get there you will need "y" turbo @ "z" psi.

i have talked to you before and you seem like a smart peron that is doing their homework, and im sure the turbo you have chosen is properly sized, and 9 psi from it will be safe, i was just trying to make a point that you do need to have a specific HP goal in mind when trying to decide how much boost your gonna run and from what turbo.

[ghost_masterCL]

stock is 270cc and you think 300cc will be enough? i dont believe it. the only way those injectors are gonna feed enough fuel is if you are running 80psi of fuel pressure, and while that could work its not the "right" way to do things. get big enough injectors that you can run stock fuel pressure.

yeah but 9 psi on a T88 could make 450-500hp and blow your motor, while 9 psi on a little T3 might only make 250HP and be perfectly safe. you cant just go off of boost pressure, as there are so many variances with turbo sizing and efficiency rates. thats why you usually shoot for "x" amount of horsepower, and to get there you will need "y" turbo @ "z" psi.

i have talked to you before and you seem like a smart peron that is doing their homework, and im sure the turbo you have chosen is properly sized, and 9 psi from it will be safe, i was just trying to make a point that you do need to have a specific HP goal in mind when trying to decide how much boost your gonna run and from what turbo.

stock on the J30 is actually only 240cc, and yeah you're right I wasn't thinking about it in the right way. I'll probably grab 370cc injectors as that seems a good size.

honestly I'm pretty surprised that guy was running the 270's with the GT35 @ 6psi. He made I think 394 whp.

[Kwando]

i have a set of stock s2k injectors if you are looking for some... they have approx 29000 miles on them, they came off my 01 s2k.

[ghost_masterCL]

I would, but unfortunatley they only work on the J32 fuel rails, and not the J30 fuel rails.