Turbos;injectors;CFM;lbs/min

ok so I was trying to figure what would be the best choice for Fuel Injectors, so i was looking up turbo flow charts and such, and hers what I got so far.. Perhaps this can help others out in the future...

Mitsubishi OEM Turbo Specifications *Flow Rates @ 15psi*
TDO4-9B-6CM2 265 CFM
TDO5-12A-8CM2 320 CFM
TDO4-13G-5CM2 360 CFM
TEO4-13C-6CM2 360 CFM
TDO4L-13G-6CM2 360 CFM
TDO4L-15C-8.5CM2 390 CFM
TDO5H-14B-6CM2 405 CFM
TDO5H-14G-8CM2 465 CFM
TDO5H-16G-7CM2 505 CFM
TDO5H-16G-10CM2 505 CFM
TDO6-17C-8CM2 550 CFM
TDO6H-20G-14CM2 650 CFM
TDO7S-25G-17CM2 850 CFM
TFO8L-30V-18CM2 1200 CFM

To calculate the flow rate with a turbo you multiply the cfm by the PR (pressure ratio)

PR= 15 + boost pressure, CFM *X* divided by 15???

Ex: 15 psi on a E316G (flows 550cfm)= 36.666 lbs/min round to 37 lbs/min just to play on the safe side...

Now according to spyderturbo007's thread (http://www.automotiveforums.com/vbulletin/showthread.php?t=676215)

that would mean that i would need a MINIMUM of 650cc injectors in order to safely run 15psi of boost all day long using under 80% IDC (playing it on the safe side and taking into account of summer temperatures of over 110 deg. F. here in Texas...

if this is correct then assuming that i want to upgrade my e316g to a 20g after i get my finances into order, then rather then maxing out at 36.6 lbs/min i would be flowing more like 43.3 lbs/min which again referring to spyderturbo007's thread, 780cc injectors would be sufficient.

ok so i dont know if my math is 100% correct, after all this is the first time i looked into all this so if anyone spots any errors, please feel free to correct me. I'm in the process of trying to figure this out as well.

I didn't check your math because I'm pretty busy at work today, but I can guarantee that you will not be pushing 37lbs/min at 15psi on the EVO III 16g. I'm running 20psi and only pushing 33lbs/min.

I'll stop back later when I have more time. I'm sure Kevin will be by since I know he loves these threads. :)

somewhere there is a website that has all the airflow tables for the popular DSM turbos..

so i would need 650cc fuel injectors to run my e316g on pump gas all day long @ 15psi... they why does everyone recomend 550's for 16g's? i'm a little confused... i guess the reason for this whole thread is to figure out what injectors i should purchase. i'm looking to max out my 16g within the next few months, and upgrade to a 20g (bastered by SBR). what injectors would i NEED to run a set up like that in 110 deg. F. outdoor temps on 93 oct. pump gas at 11:1 fuel ratio? *getting specific i know, but any suggestions will help!

i here everyone say "get 950cc's" well, F-that! thats WAY overkill! i dont want anymore then what i need! and i will NEVER go bigger then a 20g and if i do, i will be pooring so much into this car, the new injectors can just be added to the list.

over all goal is 400whp as SAFELY as possible.

So again, what injectors would you guys suggest to safly max out stock block *???hp*/pistons*450hp*/rods*400hp*/head*???hp* (slight port, 272 cams, cam gears)/20g turbo/PERFECT tune? i'm thinking probably like 780cc's but again i dont want anything overkill... but i want to be on the safe side of bigger... just let me know if this is about where i should be. thanks

I do love these threads! :D I'm not going to check the math either, I'll just ramble on as I usually do.

In my most humble of opinions, there is only one reliable way to determine your minimum fueling requirements. That is to provide enough fuel to cover the maximum mass flow rate your installed (or future planned) turbo supports. I do not recomend sizing fuel system components based on some given boost pressure, ET, horsepower number, etc.

The reason is that (I feel) you want enough fuel capacity available to cover you in the worst case scenario, and that is maximum boost, wether set on the boost controller by the owner, or achieved accidentally because of a malfuction (like the MBC line melting on the exhaust manifold, etc). I'm willing to bet that in the vast majority of cases where an engine blew due to excessive boost (malfunction), lack of fuel was the cause. If you have the fuel available, and things go wrong, the ECU will see the extra air and add the fuel, giving you a much better chance of getting by with your shit intact. Another obvious advantage to doing things this way is that once you grow some balls, dump in the race gas, and crank things up to max out your current setup, you know you have enough fuel to do it. Being limited by a (expensive) turbo is one thing, but being held back by a set of 300 dollar injectors when you spent 295 for the next size down is just stoopid. :)

The 950 recomendation is for people with DSMlink or other tuning solutions that allow for large injector size compensation. If 950s run like stock, why go smaller? They may be "overkill," but there is no real disadvantage. Conversely, there are plenty of disadvantages to going too small. ;)

All that being said, size your fuel system based on the maximum mass flow of the turbo (lb/min or equivelent, not CFM), the Specific Gravity of the fuel being used (typical pump gas is .75, race fuels .70 to .73), base fuel pressure, and air:fuel ratio. I'm in no real mood to go into the mathematics, but myself or others may have done so here in the past. To put it basically, find your mass fuel flow requirement based on your air fuel ratio, use the density of the fuel to determine how much volume flow you need to get that mass flow, and with a bunch of unit conversions arrive at some value in cc/min. It's a lot simpler than it sounds luckily. [Edit> Note that these calculations use REAL numbers as measured on people's cars, not some obscure BSFC estimates, huge fudge factors, etc. I have found that doing the math in this way results in accuracy to within .1 AFR, less than 1% IDC, etc.]

To use your 20g situation as an example, pump gas, target AFR of 11:1, and 42 psi base fuel pressure, 650s would see 101.7% IDCs. With race gas (.73) and 12:1 AFR, 95% IDC. This is obviously the very lowest you could get away with.

To provide some mass flow ratings for other turbos (as measured on my car in most cases):

14b 30 lbs
small 16g 36 lbs
big 16g 39 lbs
evo 16g 42 lbs
20g 48 lbs
EVO Green 49 lbs
50 trim/Green 50 lbs
GT3076R/3052 52 lbs
60-1/Red 62 lbs
35R/GT14 65 lbs
T67/GT37R/3575 75 lbs

Using typical values for AFR, fuel, etc:

450s - 32 lbs/min
550s - 40 lbs/min
650s - 47 lbs/min
750s - 55 lbs/min
850s - 62 lbs/min
950s - 69 lbs/min
1000 - 72 lbs/min
1600 - 116 lbs/min

You can see another reason the 950s are so popular, they support the 65 lb wheel in the GT35R and other turbos it's used in (GT14, 3065, 3565, etc), which is the largest 99% of DSMers go, even on strokers. It's also worth mentioning that x80 injectors flow like x50 injectors despite the name. Last I looked into it I recall them being rated at 45 psi or higher, which gives them the higher flow rating. The x80 injectors invariably act just like x50s, so choose accordingly.

And for the sake of being thorough, the same math applies to fuel pumps, but it's more difficult since boost and therefore fuel pressure affects the flow. But as a general rule, for those not inclined to figure it out right down to the exact pressure, at 30 psi (common stopping point for most poeple), the intank pumps support:

1g - 17 lbs/min
2g - 27
190- 31
EVO8- 34
255LP- 54
255HP- 64
Supra- 73
Etc...


Hopefully something in this bloody mess is useful to someone...

i never knew that 950's could be pulled back enough to run like stock! so thats why everyone kept telling me to get them! thanks a ton Kevin! you've made my day! no more lost hours of sleep wondering what i need to buy in the near future... (running WOT @ 9:1 AFR *narrowband*) *but only reached WOT one time... and that was enough for me to be convinced on dropping the $$$ for link and injectors ASAP! (450's suck!) after your feedback kevin, which i again, thank you for, i have decided to go with the 950's for safty reasons! always better to have to much fuel as opposed to not enough...

The key to getting the 950s to run like stock is the ability to adjust the injector latency (or dead time, or battery offset, whatever you want to call it), which DSMlink provides. I ran 950s for years with perfect fuel trims and rock solid idle. Same story when I was running the DSMlinked 2g ECU in the EVO with FIC 950s.

Add a wideband and MAP sensor to your DSMlink and you'll have the ultimate tuning setup. That configuration with your setup (plus cams) runs 11s pretty regularly.

Add a wideband and MAP sensor to your DSMlink and you'll have the ultimate tuning setup. That configuration with your setup (plus cams) runs 11s pretty regularly.
i'm already looking into widebands, however, what is this "MAP sensor"? i've also heard alot about a GM 3.3bar sensor for logging boost? could you elaborate a little kevin? thanks

GM 333kpa sensor of some diesel motor. DSMlink can log it so you can track manifold pressure. Very helpful. I'm sure you can find a part number in the DSMlink forums. I'm too shitfaced right now to find it myself. ;)

GM 333kpa sensor of some diesel motor. DSMlink can log it so you can track manifold pressure. Very helpful. I'm sure you can find a part number in the DSMlink forums. I'm too shitfaced right now to find it myself. ;)
would that be worthwhile to use in place of the 3.3bar sensor? or should this be used in addition? :screwy: i dont have access to dsmlink forums... if anyone would find this part # for me, that would be much appreciated! :banghead:

The "3.3 bar" is another another same for that same GM sensor. If you have that one, you're all set.

Here is the post from a friend of mine and local DSMer, he found it.

During a recent diagnosis of a check engine light on a duramax diesel truck, I found a dtc for an overboost condition set at 38 psi. Figuring the factory boost sensor should be able to accuratly read this level, I ordered up a boost pressure sensor and hooked it up to a 5volt reference and a boost guage. The sensor flatlined at 39psi! This is a very compact little sensor and people should be able to find it through AC-Delco distributors for around 60 bucks with a little searching.

I sent the sensor off to Thomas and he is currently upgrading the client to support it, so it should be very simple to install. For more information on this little bugger, look here:

http://www.powerandsignal.com/docs/P...re_sensors.pdf

The part number for the sensor is as follows:
GM: 9373269
ACDelco: 213-951

If anybody can locate a pigtail and connector part number, please post them, as I can not seem to locate them yet. I just made up three jumpers and plan to silicone them into the sensor.

Much thanks to Thomas for getting this intergrated into the link!


Thread is here, (http://www.dsmlink.com/forums/showthread.php?t=5081&highlight=3.3+sensor+part+number) for those with DSMlink access.

And the pigtail connector to wire it up cleanly:

"Connector"
ACDelco # PT1799
GM # 88987997

Ok not to hijack or come off sounding like a dumbass but im trying hard to understand this. With my setup now, an e316g @20 psi flowing less than 42 lbs/min (so 420 hp is max for this turbo?) 550 injectors with 40lbs/min (400 hp max for these injectors?) and rewired 190 @ 31-33lbs/min (im guessing) so between 310hp and 330hp is where i would max out on the fuel pump? This all being 11:1 AFR according to the wideband. Since ur only as strong as ur weakest link would that mean that near 310 hp or just above that is where my hp is limited to? If so to max out the E316G i would need a 255 walbro, FPR and newer injectors. Now ive read that 650's is as high as u want to go when ur just controlling with an AFC. But my friend has some 720's that he will sell me from his 95 gst. He was controlling them with only a SAFC 2 (which i rode in) and the idle and everything was perfect, and he didnt have the afc maxed out on lean either. So correct me if im wrong but if i were to switch to say a 20G or a 50 trim, 720s would do me fine. (Not using DSM Link) Also i read somewhere that if u take the lb/min and add a decimal that is where the hp should be. Which is what I based this whole deal on. So hopefully im in the ball park. Anyway I guess what im asking is will 720s with the 20G or 50 trim be what i need to max out those turbos or at least come close? Again forgive me if I sound like i dont know what im talking about because im just trying to understand this equation, and since im not good at math its a bitch

Ok not to hijack or come off sounding like a dumbass but im trying hard to understand this. With my setup now, an e316g @20 psi flowing less than 42 lbs/min (so 420 hp is max for this turbo?)

Roughly. Some have gone higher, but 400 is the typical max.

550 injectors with 40lbs/min (400 hp max for these injectors?)

With race gas and leaner AFRs you can get a little closer to the limit of the turbo, but they are a touch too small.

and rewired 190 @ 31-33lbs/min (im guessing) so between 310hp and 330hp is where i would max out on the fuel pump?

In the list I made above, the boost value used was 30 psi. The EVO 16g will only hold about 21 psi at redline with a typical good setup, the pump can support more. It's exactly enough to cover a EVO 16g, but it's cutting it very close. I don't mind running injectors right up to 100%, but I like to have extra fuel pump, since there is a little more variability. Pump to pump variances, wearing out over time, voltage variance, etc. Run the 190 if you like, but keep an eye on the wideband. A 255 and reg is more appropriate at this level.

Now ive read that 650's is as high as u want to go when ur just controlling with an AFC. But my friend has some 720's that he will sell me from his 95 gst. He was controlling them with only a SAFC 2 (which i rode in) and the idle and everything was perfect, and he didnt have the afc maxed out on lean either.

The real problem with larger injectors on the stock ECU is increased timing advance that comes from the decreased load signal seen by the ECU after the AFC is done tampering with it. I don't like to run over a 550 if possible, and a 650 tops, for tuning with just an AFC. Go higher at your own risk. Again, watch the logger and makes sure things are safe. You can drop timing at WOT if you have a 1g or a 2g with a 1g CAS, but you'll lose some idle, low end, cruise, etc, since the change will be in effect all the time. Choose your area to hose accordingly.

Injector compensation in the ECU with a chip will solve all these problems, bring an AFC back to 0 and therefore airflow signal at the ECU back to reality, which keeps everything in line. At this point, you have an EPROM ECU, and have spent nearly enough to cover DSMlink, which is naturally the prefered route to take. And once you go DSMlink, just go with 950s and be done with it for all of your turbo upgrades through the GT35R sized turobs.

So correct me if im wrong but if i were to switch to say a 20G or a 50 trim, 720s would do me fine. (Not using DSM Link)

They would be just enough to cover the turbo's max flow capacity, but as discussed above, you're on your own for timing. The injectors will require nearly 40 of the AFC's available 50% adjustment range. That doesn't leave enough range left to even lean out to 11:1, about another 10-15% more negative. ;) At that -50% adjustment, you would need to be flowing over 4 lbs/min to have normal timing and target AFR which is more than even a 50 trim or 20g can provide... Not a good match.

Also i read somewhere that if u take the lb/min and add a decimal that is where the hp should be. Which is what I based this whole deal on. So hopefully im in the ball park.

Multiplying the airflow in lbs/min by ten will give you roughly the max WHP potential. Whether or not the setup lives up to that potential depends on many factors. Fuel, timing, knock, mechanical issues, etc.

Anyway I guess what im asking is will 720s with the 20G or 50 trim be what i need to max out those turbos or at least come close?

The 720s will be enough, as will the 255. The issue you need to sort out is how to properly control injectors of that size. Hopefully enough information has been provided to allow you to make the decision effectively.

Again forgive me if I sound like i dont know what im talking about because im just trying to understand this equation, and since im not good at math its a bitch

You also seem to struggle a bit with punctuation and grammar, or maybe just the typing, but I won't hold it against you. You're forgiven. :icon16:

Haha well i never tried to pass myself off as an english major, but at least u caught the jist of what i was getting at. Now that i think about it, you sparked my memory, because he does have the chipped ECU. No DSM link, but he has it chipped for his 880s and hes got the stutterbox, which he has 3 settings just by pushing in the clutch while the car is off. Anyway, thanks for clearing up my paragraph of questions so quickly, im def leaning towards the link now, and no exactly what fuel steps i need to take in my search for a bigger turbo.

Sorry to intervene but since dsmlink is coming up so much and kevin is a DSM god ill ask.
kevin Do you know of a dsmlink tuning guide or a how to tune by yourself because i just got dsmlink explored it thuroughly and making adjustments is very easy. The part i need help with is deciphering what i see ie A:F, airflow timing, fuel, boost, and knock and and how a change in timing and fuel how that will change those values. Id rather tune my car by myself instead of having someone else do it cuz then its MY car

I believe there is a tuning guide of some sort on the DSMlink forums. I've seen a thread for it anyway, but I've never looked at it. Actually tuning a car is not really something I can see being put into a guide, but I'm sure it provides people with a good start. I've been tuning these cars for something like 6 years, every single week, and I still learn something new at least every week. Just last week I made a pretty significant breakthrough on my car with injector timing, something most poeple never even think about. Tuning is such a huge topic. And there is so much misinformation out there it's ridiculous. It's difficult to know who you can listen to, and who is just talking with no real experience behind their ideas.

Wanting to tune your own car is the first step in the right direction. You really do have to learn by doing. It's a risky business though, so make small changes, and as you go on your knowledge and confidence will increase. When I started doing this, I had no previous experience at all. With previous cars I could bolt parts on and do maintenance stuff, but no tuning. The more you tune, the more you learn about how the ECU (and EFI in general) works. The more you know about how the ECU works, the better you can tune. :)

I'll provide a quick outline though, just to get people going in the right direction, hopefully, I feel like rambling again...

1) First and foremost, airflow determines power potential. No matter how good your tuning is, you can't make more power than the amount of air and fuel you are burning will provide. Burning air/fuel supplies the energy to do the work, the tuning just determines how efficient the motor is with that supplied energy, and how safely the motor will use that energy. In other words, don't over-tune. You can't make power magically appear through tuning, there are limits.

2) Airflow is power potential, boost is heat (knock). Increase airflow by increasing boost, or increasing the motor's ability to move air at a given boost pressure (cams, intake manifold, exhaust, larger turbine side, more displacement, better intercooling, etc). At some point you won't be able to get away with more boost (knock limited fue to pump gas, etc), and moving more air at the same boost will be a worthwhile pursuit. This is absolutely key for pump gas power.

2) Every setup is different, but the AFR you want to run is pretty well established. On pump gas, 11-11.5. On race gas, 11.5-12.5. Play around with it and log the results, but don't expect huge changes if the rest of the tune/setup makes sense. AFR doesn't have a significant effect on knock until you get real lean, or a real significant effect on power until you get real rich.

3) Timing is a whole other story. This is the big voodoo magic variable. Timing has a significant effect on both power and knock. It's also on a bit of a curve. The trick is to recognize when you have reach the point of diminishing return and stop increasing it. On pump gas, you'll typically knock before the power increase with each degree added starts to drop off noticeably. On race gas you can actually start to lose power and break stuff before you pick up any knock. In the meat of the curve, expect 10-12 whp or 1 mph per degree added. If you start adding 2 or 3 degrees and picking up 5 whp, it's no longer worth pursuing. Drop those 2 or 3 degrees back off, give up the 5 whp, and keep the added safety margin. ;)

4) With timing and AFR in the "normal range," more boost will always make more power. In other words, don't sacrifice boost to get extra lean AFRs or more timing than usual. It almost always makes less power. Taking out a degree of timing and increasing boost a few psi will almost always yield more power. At the same time, don't completely bollix the timing, or run excessively rich AFRs, to try to run excessive boost just to impress your friends.

5) Make some changes, log the results, and try to quantify any HP gain or loss (track trap speed, dyno, or datalog a fixed speed range, like 70-90 mph in third, and note the time it takes). And repeat for the rest of your life. This process will never change. It's time consuming, but necessary. Never trust the ass dyno, trust the data.

6) When you've done all the tuning you can, and you're still not making as much power as you think your setup should or as much as others are making, don't overlook the "mechanical tuning." Cam timing. Compression ratio. Combustion chamber characteristics. Parasitic loss. Turbine/exhaust size. Intercooling capacity. Intake restrictions. And so forth. When you get really bored, go to a full standalone and see the tons and tons of bullshit you never knew existed, and start the learning process on the steep end of the curve again. :D

It's one big learning process that can be rewarding at times, and dissapointing at times. Good luck, and enjoy. :)

thanks a lot ill probably just take it really slow and try not to break anything. I have a completely different set of problems... altitude lol being a mile high sucks sometimes :(

Bah, just turn the boost up.

:)

ya i keep trying but i cant figure it out i have a joe p with the T hanbdle and the hex screw but i cant figure out which one i have to turn which way to turn it up i wanna set it at 17 cuz im getting 2lbs of creep and hit 19. but i had 3.5 degrees of knock 6533 rpm at 16/17psi surge and 2nd gear pull so i decided to add more fuel and be safe but im upset cu if im pulling knock at 15psi i wont be able to advance the timing any especially at higher boost. i feel like this thread got a different topic :uhoh: i dont want to do anything too much because i dont have a WB yet and i dont know exactly what AF im running and i dont wanna blow anything up.