Have a few questions about how to get the most out of the siemens 80 lb injectors.. Ives seen where some are maxing theres out at 700ish and some are breaking triple digits. If those of you running these injectors could share your setups and numbers that would be great.

I plan on running on running twins on a 6.0 iron block, l92 heads with eBay studs, ls3 intake, ls9 cam on 93 pump gas. I plan on twin walbro pumps with -8 an feed and stock feed for return on a 97 firebird to the stock LS3 rails. The turbos are GT3582 eBay turbos:
Compressor trim: 56mm
-Ind: 61.5mm
-Exd: 81.5mm
-A/R: 0.7
Exhaust trim: 84mm
-Ind: 68mm
-Exd: 62.4mm
-A/R: 0.63

From my current plans stated above, would changing feed line size, adding another walbro, or upgrading fuel rails improve the efficiency of these injectors? I want the most efficiency out of them and certainly don't want to have them struggling at 700hp. Also what fpr would y'all recommend and what filters are y'all using, how many, and where are they located? If running 2 feed lines to each rail will help I can do that.

Mainly want to focus on fuel setup but have some other questions if you guys happen to have some info. I am currently running LS6 springs and wondering if I should go ahead and upgrade to pac 12 springs or if I should just do trunion upgrade or titanium retainers.. Im on a budget so id like to keep the LS6 springs but for some reason Im not too confident in them. I am definitely keeping the stock rods, pushrods, and pistons for now..

Thanks for any and all info y'all are the ****

 

My 3800lb car trapped 141 with siemens 60lb injectors. My weight and trap suggest I make around 800rwhp so I would think 80lb injectors would be good for a lot more power.

 

Those setups maxing out around 700 are on e85. Sound like you are planning on pump fuel, no?

 

Nice thats good to hear! and yeah pump gas. Thanks fellas

 

What fpr are y'all using? I would like to run the stock ls3 rails.. Will a fpr at the front of the drivers side give a good enough reading over all the injectors?

 

If your at 800rwhp with 60's please share your fueling setup because that's rockin lol.
I made about 600rwhp at 80% IDC with my Siemens 60's when my tuner suggested I upgrade to 80's which should max out around 800rwhp on pump swill.

 

850 rwhp with 80 lbs and meth. 408, TFS 245s, Huron Speed kit with a BW S480.

 

We have a customer with a 408 blown using 80s and 2 #15 meth sprayers (this helps a good bit) making 940 wheel. It is set at a base of 62psi wtih a 1:1 boost reference, Has been running this way for about 3 years now.

 

Do you guys have any recommendations on a FPR? Ill probably run the Hobbs switch to activate the second pump..

Anyone have experience with the Aeromotive 13101 FPR for $160? Ive heard some good things.. If I end up going this route ill probably go ahead and do aftermarket rails each being fed from the rear with a crossover in the front with the 13101 in-line with a -6 return coming off of it.

I also read up on mightymouse's setup where he uses the speed inc regulator on the return side.. with this reg on the return, would you just plug the return port? The one I assume he used has the feed from tank and return back to tank on one side and outlet to rails on the other..

 

I use the Aeromotive 13129. $120 from Summit.

 

Twin 255's with stock lines, fuel rails, and fpr. siemens 60lb injectors. They are maxed out though. Goes from 98% duty cycle to 100% depending on rpm. A/F is perfect though so not worried about them yet.

That's one thing I don't like. I hear the 24/7 it seems like. TONS of people get told to upgrade so they do it and never get anywhere close to maxing out the old injector or pumps. Makes sense to leave room to grow, but also makes it hard to know how far some things will go..

 

I'm using the 80s with a dual m15/m10 methanol setup on 91 pump gas made 907whp with a stock in tank c6 z06 vette pump with BAP and an A1000 setup on a hobbs. base is around 57-58psi and using that aeromotive FPR also at 1:1 boost reference.

rock solid fuel pressure all the way up to 175mph+ at 1/2 mile. I don't remember IDC off the top of my head but I remember I was not even close to 100% IDC and not worried at all.

methanol helps for sure and I recommend at least.


one thing to know is the 80lb siemens injectors will boost leak at the intake manifold with an ls7, and I've been told ls3 too, intake manifold. Katech sells oversized injector o rings which fix this.

 

Awesome info I appreciate it ill definitely replace the o rings. I know methanol will be a future upgrade but I want to get everything up and running on pump gas before I go meth and a few other things like forged rods/pistons, drivetrain upgrades ect.. I want to be able to hang around the 7-800hp range with room to grow later on but want a solid foundation. I am on a budget but also doing everything myself which unfortunately makes up for a pretty long timeline before I'm launching on 15-20 pounds of boost :use:

Got my head studs and fuel system ordered today with the exception of the aeromotive FPR and hobbs switch which ill order in the next couple days. A couple of GT35's and piping, FMIC will be on the way shortly.

Hopefully picking up a 4l80e on Sunday but never know with craigslist.. If it works out will be ordering transgo shift kit. Having the hardest time deciding between the 4l80 and t400. Trying to figure pricing comparison to build them considering the deals I come across.. Would like to think a 4l80 will fit my budget but won't be too disappointed if I have to sacrifice overdrive if the price gap is noticeable. Another obstacle is the trans crossmember with a torque arm mount which I'm gonna have to fab. No way I'm paying $280 or whatever it is for a crossmember and have to modify it or spend more on a tunnel mount T/A.

Also have my eye on an 8.8 housing for cheap that Ill be building.

The build is a 97 v6 firebird a picked up a couple weeks ago that was wrecked and had front end damage which was ok with me bc I plan on a 98-02 front end conversion anyway.. Had to drive 4 hours, pull the motor trans on a slanted driveway, and took home the roller for dirt cheap. I was originally building a 95 z28 roller but ended up selling it for a price I couldn't refuse. I had acquired a 98-02 ls1 front end, steering column, and radiator that ill use in the firebird.

 

hey a little note on the 13101 fpr vs the 13129

the 129 has all -6 inlets and outlets and feed

the 101 has -10 inlets, feed and a -6 return

i'm not sure if it makes any difference in your application

i use the 129, shooting for 750 wheel on pump and meth through an unlocked auto

 

What's the HP cut of typically for either of those inlet/return sizes?

 

I have no idea.lots of guys making tons of power on -6.
but -6 is less than 3/8" i.d.
I was pretty bummed when I redid my feed line to -8 and poor planning meant I had to neck it down to -6 at the FPR
probably have to upgrade the fpr if I mess with corn

 

​​​​​For an efi fuel system there is no HP cut for line size.

 

That's beautiful, my setup is identical lol except w/ 80's now.
I sold the old injectors and got these on a deal from a friend so I wasn't out of pocket.
Are you using an aftermarket FPR?
I got a few people recommending to add one for stability.

 

I ended up going with the 129.. Im only using one of the inlets right now until I either ad a bung to the PS fuel rail or go with new fuel rails which Im not wanting to do.. For now this will work because I've still got some touching up to do on the hot side piping and a lot of tuning before ill be pushing it.

I'm in a little predicament with my setup though because I bought a Firebird with front end damage and it didn't have the front bumper, lights, and everything in between.. So Ive been trying to fab up my turbos not really knowing if its going to work.. Just going off pictures and estimating. I have my turbos mounted but I think they are too high for the hood. Ill post a pic and see what you guys think but ill probly be moving them down and a couple inches towards the motor for a more efficient and direct hot side.

 

Any of you guys that happen to have some useful measurements I could go by would be a huge help. Its a '97