365cc injector too big?

Hi normality, I have the formula for calculating the size of injectors best suit you. I've done this based on research from various sources. Hope this helps.

Get the size of the injector in flow (cc/m) then divide that by 10.4, which gives you the imperial rating of the injector in lbs/hr. The overall horsepower potential of that injector is now gained by a simple multiplication by two. Then subtract 10 per cent to give a ‘real world’ margin and you have the true horsepower number that a single injector will flow. Multiply this by the number of injectors and you have the results. Take for example:

550cc divided by 10.4 = 53 (rounded)

53 lb/hr multiplied by two = 106

106hp with 10 percent subtracted = 96 (rounded)

96 multiplied by four = 384

384hp should be roughly these injectors’ total flow

You need to use some nous when performing these mental gymnastics, though, as taking the results literally can be confusing. For example you would expect that possibly, at a push 400hp should be within the range of the 550cc injectors. From there its easy to do these mental calculations whenever the subject arises, and even though it’s far from the most scientific approach, the results are very accurate. All you need to do now that the sizing issue is under control is to start saving.

Working the other way round, say your aim is to hit a mild 300hp, work the calculations from bottom up:

300hp divided by 4 = 75hp

75hp with 10 percent addition = 82.5hp

82.5hp divided by 2 = 41.25 lb/hr

41.25 lb/hr multiply by 10.4 = 429 cc



Formula : ( cc) flow of injectors / 10.4 = [ lb/hr ]

( lb/hr ) X 2 = [ hp ] horsepower potential of injectors

( hp ) - 10% = [ hp ] in ‘real world margin’

( hp ) X no. of injectors = HP of injectors total flow
 
normality78 said:
yup. im running emanage now. its a piggyback.

on off boost, its all minus until the end liao but still damn rich. but whn run in boost, its enaugh as its still got more. its still in minus side though... i was being told that if s/alone thn no such problem coz s/alone injector driver is more capable

Use the injector size compensation utility found inside the E-Manage Tuning Software. What's wrong with your tuner? He don't understand how to use the software ? Or are you trying to monkey with somwthing you don't understand?
 
cipan_supercas said:
Use the injector size compensation utility found inside the E-Manage Tuning Software. What's wrong with your tuner? He don't understand how to use the software ? Or are you trying to monkey with somwthing you don't understand?

er... i tried to be monkey myself but too bad i dun even know a single shit to monkey it. whahahaha. Actually i leave it to tuner to do the magic. i dun really know how capable can the emanage do. but im sure emanage is sufficient enaugh to meet my demand. afterall mine was not any big project but only a normal simple BOT
 
Last edited:
edgar_raphael said:
Hi normality, I have the formula for calculating the size of injectors best suit you. I've done this based on research from various sources. Hope this helps.

Get the size of the injector in flow (cc/m) then divide that by 10.4, which gives you the imperial rating of the injector in lbs/hr. The overall horsepower potential of that injector is now gained by a simple multiplication by two. Then subtract 10 per cent to give a ‘real world’ margin and you have the true horsepower number that a single injector will flow. Multiply this by the number of injectors and you have the results. Take for example:

550cc divided by 10.4 = 53 (rounded)

53 lb/hr multiplied by two = 106

106hp with 10 percent subtracted = 96 (rounded)

96 multiplied by four = 384

384hp should be roughly these injectors’ total flow

You need to use some nous when performing these mental gymnastics, though, as taking the results literally can be confusing. For example you would expect that possibly, at a push 400hp should be within the range of the 550cc injectors. From there its easy to do these mental calculations whenever the subject arises, and even though it’s far from the most scientific approach, the results are very accurate. All you need to do now that the sizing issue is under control is to start saving.

Working the other way round, say your aim is to hit a mild 300hp, work the calculations from bottom up:

300hp divided by 4 = 75hp

75hp with 10 percent addition = 82.5hp

82.5hp divided by 2 = 41.25 lb/hr

41.25 lb/hr multiply by 10.4 = 429 cc



Formula : ( cc) flow of injectors / 10.4 = [ lb/hr ]

( lb/hr ) X 2 = [ hp ] horsepower potential of injectors

( hp ) - 10% = [ hp ] in ‘real world margin’

( hp ) X no. of injectors = HP of injectors total flow


TKs... for the info bro. I will need some time to digest off the info.
 
what ecu you running? i think should be the stock 4AFE ecu right?
I never try on FE ecu, i think both GE and FE are using same 5v vaccum sensor. so u can try this.

there is a trick to solve this problem easily. use the 4EFTE or 4AGZE turbo pressure sensor to replace your vaccum sensor.
i'm sure u can idle it well, then bring it back to dyno tuned again.

from my experience..
i built my 7A-GE turbocharged by running with 4A-GE AE86 ecu, map sensor from 4EFTE and injectors 365cc. i run pretty smooth 1bar boost by just using SAFC to correct to fuel map. then i switch to 4agze ecu with 440cc injectors running 1.2bar.
now i run 550cc injector, 2bar with microtech ecu, was 3rd runner up in 2006 borneo drag group A turbo open 2WD.
 
yup. im running on 4AFE ecu. Yeah, i do know it was the same vacum sensor.

FYI, i've already changed to haltech 3bar map sensor. so does that mean instead of using haltech 3 bar map sensor, i shld give 4efte/4agze map sensor a try? could it be 3bar map sensor abit too "big" for me?

abit off track, can i assume that i can replace my ecu to 4agze by just swapping it over? how about wiring side?
 
bro... just take a 4E map sensor a try.. because it come with juz 1bar map sensor so the signal to ecu is not as wide as 3bar map sensor.

i dun use stock map sensor for microtech, my MTX-8 come with built in 2 bar map sensor.
 
normality78 said:
cipan_supercas,
what does injector size compensation utility work as?

In E-Manage support tool Parameter settings, you can see that there is a provision for you to enter the injector size you recently change versus the size of the original fitted injector. Support tool will calculate upon your entry of these numbers. That will get you a better idle to as the original settings or close to it. The rest of the table can be mapped using proper tools for tuning.

suggestion..;
Since you have that Haltech 3 bar map sensor, hooked that up to the original wiring and discard the oem sensor. Unless you use additional injector/injectors, then direct wiring of the Haltech map sensor into the E-Manage is required.
 
cipan,
yeah, this is my intention to do now. I was thinking to get rid the stock map sensor which i see no point of keeping (pls correct me if im wrong) and hook up solely on the haltech map sensor only.

i manage to find a toyota turbo map sensor but infortunately im not able to know from which car is was from, how many bar map and also the most important thing is does it work. whahahaha. can any of you tell frm the code given?

http://img120.imageshack.us/my.php?image=pb230201111fw9.jpg

http://img329.imageshack.us/my.php?image=pb230202111ke8.jpg

http://img329.imageshack.us/my.php?image=pb2301971111we7.jpg
 

Similar threads

Posts refresh every 5 minutes




Search

Online now

Enjoying Zerotohundred?

Log-in for an ad-less experience