Recommendations on Fuel System & Injectors for SC

[orangy]

Hi everyone,

What type of injectors would i need to purchase for a Supercharged LS7.

The Cars specs are:
2007
Chevrolet Corvette C6 Z06
LS7 7.0L 427ci

Application:
ATI Procharger
P1-SC-1 or D1-SC
runnig boost from 4.5-6.0 lbs

What kind of injectors would i need to keep my engine and my tune safe. People here told me the stock injectors and the fuel system are not safe for a car running 560+ rwhp

So what do you recommend me on for this application.

Please give me name of companys or at least some links so that i can check for it to order them.

Thanks alot guys...

Wish me luck..

[rz01]

Originally Posted by orangy

Hi everyone,

What type of injectors would i need to purchase for a Supercharged LS7.

The Cars specs are:
2007
Chevrolet Corvette C6 Z06
LS7 7.0L 427ci

Application:
ATI Procharger
P1-SC-1 or D1-SC
runnig boost from 4.5-6.0 lbs

What kind of injectors would i need to keep my engine and my tune safe. People here told me the stock injectors and the fuel system are not safe for a car running 560+ rwhp

So what do you recommend me on for this application.

Please give me name of companys or at least some links so that i can check for it to order them.

Thanks alot guys...

Wish me luck..

You will indeed need to upgrade your fuel system at elevated power levels (over 560 rwhp). A&A Corvette has a system that people have used on a SC'd LS7.

[MikesZ06]

The stock fuel pump should work just fine at 4.5 or so lbs of boost but you will need different injectors. The Procharger kit used to come with 42lb injectors (I think) but you'll have to ask if that is still the case.
You can use 42lb or even bump up to 65lb injectors if you feel better about it.

Mike

[orangy]

Originally Posted by rz01

You will indeed need to upgrade your fuel system at elevated power levels (over 560 rwhp). A&A Corvette has a system that people have used on a SC'd LS7.

Thanks alot rz01

I am still looking for them on the web.

[orangy]

Originally Posted by MikesZ06

The stock fuel pump should work just fine at 4.5 or so lbs of boost but you will need different injectors. The Procharger kit used to come with 42lb injectors (I think) but you'll have to ask if that is still the case.
You can use 42lb or even bump up to 65lb injectors if you feel better about it.

Mike

Thanks alot Mike for passing by...

I found some which are provided by siemens but i dont know about their reputation and i dont know if they will fit the LS7.

They are as descibed as:
1) Siemens 60lb LONG High Resistance
2) Siemens 60lb SHORT High Resistance

I dont know which is preferred or is recommended for my LS7

Thanks guys

[FRC Tom]

60 Lb injectors flow 69 lbs with our 4 bar fuel pumps.
The new computers have a 63.5 lb max limit.
55 lb injectors will flow at 63.5 lb.

[rz01]

Originally Posted by orangy

Hi everyone,

What type of injectors would i need to purchase for a Supercharged LS7.

The Cars specs are:
2007
Chevrolet Corvette C6 Z06
LS7 7.0L 427ci

Application:
ATI Procharger
P1-SC-1 or D1-SC
runnig boost from 4.5-6.0 lbs

What kind of injectors would i need to keep my engine and my tune safe. People here told me the stock injectors and the fuel system are not safe for a car running 560+ rwhp

So what do you recommend me on for this application.

Please give me name of companys or at least some links so that i can check for it to order them.

Thanks alot guys...

Wish me luck..

Are you going to stick with a stock motor? Are you going to add a cam later? What is your rwhp goal? Anything over 600 (or even maybe a little less depending on the dyno!!) you HAVE to do something to the fuel system. This is not an injector issue (although you do have to upgrade those and i believe the procharger kit comes with the new ones), but a "commanding" of more fuel issue in the tune. Here is someone I know personally who leaned their motor out on top because they did not realize the limitation I spoke about in an earlier post:

http://forums.corvetteforum.com/show....php?t=1839366

[BfB]

Originally Posted by MikesZ06

The stock fuel pump should work just fine at 4.5 or so lbs of boost but you will need different injectors. The Procharger kit used to come with 42lb injectors (I think) but you'll have to ask if that is still the case.
You can use 42lb or even bump up to 65lb injectors if you feel better about it.

Originally Posted by FRC Tom

60 Lb injectors flow 69 lbs with our 4 bar fuel pumps.
The new computers have a 63.5 lb max limit.
55 lb injectors will flow at 63.5 lb.

Everyone:

The stock injectors flow approx. 41.74# (at 58psi). I believe the injectors Procharger included were a Bosch/Ford green-top injector (from the Lightning truck). These Lightning injectors flow approx. 40.68# at 39 psi. At 43.5psi (3-bar) they flow approx. 42.96#, and at 58psi (4-bar, what most 97+ newer GM vehicles run) they flow approx. 49.61#. On a supercharged or turbocharged 4-bar setup, I really don't think I would trust these injectors much past 575 to 600 rwhp Actual.

As for the SD 60# injectors, they flow approx. 62.7# at 3-bar. They got the 60# name because of when using on Ford (39psi) they flow approx. 59.x#. On a GM 4-bar they flow approx. 72.4#. The SD 55# injectors flow approx. 56.9# at 3-bar and and approx. 65.7 at 4-bar.

(FYI: To figure injector size from differences in pressures, use this formula: √[new pressure / old pressure] )

When figuring injector sizes, keep in mind, since we now have a supercharger to turn, that soaks up some power (about 25 to 75 rwhp, depending on the blower rpm and boost level). i.e. if we're making 600 rwhp, flywheel hp would be approx. 667 (10% driveline loss) to 706 (15% driveline loss), and then you need to add blower drive power losses to that. There's a couple of good worksheets/calculators you can search and find on the net (just google "injector calculator").

You also need to go by "Actual" horsepower numbers, and not some corrected figure. i.e. at sea level, a 600 rwhp Actual vehicle is probably making around 500 to 525 rwhp at 5k feet elevation (such as Denver).

Furthermore, as mentioned above, the new pcm based systems (E40/E38/E67) have a max limit of 63.49257 for the injector slopes. Because of this limit, the 55# injector would probably be okay for tuning on a return based system (flat table), but on the returnless system it may not be, since the injectors flow more at higher kPa.

HP Tuners is working on a 2.5bar setup for the E38 based systems, which will add a HOST of new features (extended MAF range, VE table support, etc.), and it should also include a fix for the injector limit.

I'm excited about this!

Regards,

James

[orangy]

Originally Posted by BfB

Everyone:

The stock injectors flow approx. 41.74# (at 58psi). I believe the injectors Procharger included were a Bosch/Ford green-top injector (from the Lightning truck). These Lightning injectors flow approx. 40.68# at 39 psi. At 43.5psi (3-bar) they flow approx. 42.96#, and at 58psi (4-bar, what most 97+ newer GM vehicles run) they flow approx. 49.61#. On a supercharged or turbocharged 4-bar setup, I really don't think I would trust these injectors much past 575 to 600 rwhp Actual.

As for the SD 60# injectors, they flow approx. 62.7# at 3-bar. They got the 60# name because of when using on Ford (39psi) they flow approx. 59.x#. On a GM 4-bar they flow approx. 72.4#. The SD 55# injectors flow approx. 56.9# at 3-bar and and approx. 65.7 at 4-bar.

(FYI: To figure injector size from differences in pressures, use this formula: √[new pressure / old pressure] )

When figuring injector sizes, keep in mind, since we now have a supercharger to turn, that soaks up some power (about 25 to 75 rwhp, depending on the blower rpm and boost level). i.e. if we're making 600 rwhp, flywheel hp would be approx. 667 (10% driveline loss) to 706 (15% driveline loss), and then you need to add blower drive power losses to that. There's a couple of good worksheets/calculators you can search and find on the net (just google "injector calculator").

You also need to go by "Actual" horsepower numbers, and not some corrected figure. i.e. at sea level, a 600 rwhp Actual vehicle is probably making around 500 to 525 rwhp at 5k feet elevation (such as Denver).

Furthermore, as mentioned above, the new pcm based systems (E40/E38/E67) have a max limit of 63.49257 for the injector slopes. Because of this limit, the 55# injector would probably be okay for tuning on a return based system (flat table), but on the returnless system it may not be, since the injectors flow more at higher kPa.

HP Tuners is working on a 2.5bar setup for the E38 based systems, which will add a HOST of new features (extended MAF range, VE table support, etc.), and it should also include a fix for the injector limit.

I'm excited about this!

Regards,

James

Thanks alot James,

Thats what i am talking about, you gave me a pretty good detail of what i am looking at. So for my vehicle i suppose i will go with one of either 50# or 55#. Depending on our cars.

My friend has fixed a Vortech SC on his new C6 Z06 and with that kit he got a 60# injectors Siemens. He is really pissed of with it. He says the fuel is too rich for the car to be driven in traffic or at low speeds below 20mph.


So i think i will wait for my tuner to give me what he thinks of it and then i will tell him about what you wrote to me and i will give to him to read if we both got under one solution.

Thanks again James i appreciate you reply, it is and will be very helpful in fixing and tuning my C6Z

Best Regards

Omar

[BfB]

Not a problem. That's what I'm here for, to help out!

As for some further info:

Base FRP on a Ford is 39 psi. The great thing about the Ford electronic returnless system is that one can easily raise rail pressure electronically within the tune, provided there is enough pump, which can obviously be used to make an injector flow more. The other great thing on a Ford is their electronic returnless and return style systems are boost referenced, whereas on a GM returnless system they are not (not too much of an issue, tho).

The 60s are ultimately a great injector. They are used religiously in Fords, such as the Cobras and Lightnings. However, there is a variance of +/- 6% from the manufacturer, as is with most all non-flow matched injectors, so that could potentially mean a difference of +/- 4% from cylinder to cylinder. The good thing is that a lot of companies are offering them flow matched now.

As for tuning various injectors, most all those who tune GMs just change the IFR (injector flow rate) table, and nothing else (there's way more to tuning injectors than just modifying this table). This is done because there isn't any hard GM test data on all the various injectors, which is unfortunate. This requires raping the VE and/or MAF transfer, in an attempt at getting the fueling control correct. It's not right, but it's a bandaid that can allow one to get by. Some don't even realize this, nor understand why their vehicle often exhibits drivability quirks, however small or large.

On the other hand, those of us who tune Fords generally have the proper injector data for almost every aftermarket common injector made, thanks to the likes of Jerry W. (co-founder of SCT, and former Ford engineer and calibrator), as well as his best friend Dev (currently a Ford engineer and calibrator). They personally tested all the various common injectors at Fordb using Ford's injector test equipment and dyno, thereby resulting in the exact and proper values to input into the software.

The downside is attempting to use the data for Fords in GMs, which is often difficult, because most of the tables do not match up, and/or the data is intepreted differently, on top of the two manufacturers' fueling systems basically functioning differently.

Regards,

James

[BfB]

Also, there is a new "direct fit" SD (Siemens Deka) injector for LS2/LS7 vehicles. I think it is the one I will be going with. I know that Andy of A&A Corvette has used them succesfully as of recent. Here is some info on them:

Siemens FI11351

All tests run with n-Heptane (0.6855g/mL) @ 20oC (+/-1oC), 3.0 Bar (+/-0.01 Bar) (43.5PSI) , 14VDC (+/-0.05VDC), saturated driver wtih RC cutoff. Gas (0.735g/mL) ratings converted at a 1.035:1 ratio.

Static Flow Rate @ 43.5PSI (300kPa): 46.5 lb/hr = 5.86g/s = 478cc/min (+/-3%)
Static Flow Rate @ 58.0PSI (400kPa): 53.7 lb/hr = 6.77g/s = 552cc/min (+/-3%)
Dynamic Flow Rate 2.5ms PW @ 100Hz (400kPa): 11.42mg/pulse +/-4%
Coil Resistance: 12 Ohms (This high-impedance injector will work with all factory ECM/PCM injector drivers)
Gain: 0.75
Spray Pattern: Cone
Electrical Connector: USCAR (New-style V=EV6 / Oval / LS2)
Fitted with Viton upper and lower o-rings.
Grease supplied to lubricate o-rings prior to installation.
Dynamically flowed and grouped to within 1% tolerance using Racetronix custom injector flow bench
This injector version is fitted with Viton o-rings for use in factory G.M. LS2 fuel rails and intake.

Note: Some injector flow rates have been converted from n-Heptane test solvent to 40CFR86.113, the U.S. EPA emission test gasoline. However, n-Heptane is not gasoline and flows in most common injector designs at about a 3 to 4% lower rate than 40CFR86.113, the U.S. EPA emission test gasoline.

[MC Racing]

We have been using F.A.S.T injectors, they are 60# and work great they are the shorties and use the factory connector, other brands require cutting the connector and replacing it. If you have tried to find any 60-65# injectors they are hard to find which i havent figured out. We have them in stock thanks.

[BfB]

Originally Posted by MC Racing

We have been using F.A.S.T injectors, they are 60# and work great they are the shorties and use the factory connector, other brands require cutting the connector and replacing it. If you have tried to find any 60-65# injectors they are hard to find which i havent figured out. We have them in stock thanks.

The commonly labeled 60# injectors are quite easy to find. They are sold under a variety of company names, such as Siemens, Mototron, Accel 74620L, MSD/Edge (those are all made by Siemens Deka). There's a few companies that are selling the shorty versions of them, too.

Are these the ones that you are mentioning? Can you give any more information on these injectors? Part #, pictures, etc.?

Thanks!

[MC Racing]

Fuelairspark .....they are actually advertised as 65#. Part number is 30657. Thanks

[Racetronix]

***edited***

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