Cherokee SRT8 Forum banner
1 - 20 of 28 Posts

·
Registered
Joined
·
496 Posts
Discussion Starter · #1 ·
Right now I am on the stock vortech pulley, their injectors (SRT4 577cc injectors), upgraded the stock pump to the supplied 255LPH walbro, and Kenne Belle running full voltage, and it still leans out to 12.5-13.0 from 5k-6k rpms. Jonah tried to richen it up but IDC's just got too high and seemed like system was maxxed out.

I would think with the wally and BAP i should have plenty of fuel, but the car runs REALLY strong (11.8 @ 113 last time out, 1.8 60'). I am thinking of upgrading to seimens 80#'s, I run those in my SRT4 and really like them.

Whats your thoughts here? Underlying issue with the system or just par for the course with the setup? Plan is to pulley down one size to get boost from 5.5/6 to 8 or so.
 

·
Marathon Man
Joined
·
3,229 Posts
Many of us have maxed out our injectors and switched to the 80's. My jeep got worse once the weather got colder.
 

·
Registered
Joined
·
496 Posts
Discussion Starter · #3 ·
Thx, these require spacers too right? Intercooler already sits right on the passenger rail, pushing it up another 1/2" caused you no issues?
 

·
Marathon Man
Joined
·
3,229 Posts
My jeep is currently in the shop having the fuel system upgraded. Not sure what all is needed. I'm sure someone else will jump in with exact info on the install.
 

·
Registered
Joined
·
11,229 Posts
YOU are experiencing every bugs I worked out of my set up .
You have a PM
 

·
Straight Up Beast SON!!!
Joined
·
17,142 Posts
Yes 80# injectors will require about a 10mm spacer on your stock fuel rails or an aftermarket set because they are longer, so your fuel rails will sit a little higher and will need to 10mm spacer so that there is no play when mounted to the intake manny. PM Harrison @ Stage6 and he can get you some....
 

·
Registered
Joined
·
11,229 Posts
You will be surprised how much volume will flow with just a upgraded fuel line. Even going from 5/16 to 3/8 Or a -6 would improve the flow greatly. Maybe try that before buying new injectors. IMO that should be done either way when S/C the vehicle..

Good luck
Sorry to disagreed but he's problem is the Injectors period , being there done that . On the side note the JEEP stock Lines are good for 900+rwhp , Harrison still on stock lines making 865rwhp , Paul is making more then that and running stock lines still I believe . I will say it again , he's issue is the injectors as I guarantee that as I recently had this issue and upgraded to twin walbros and was still going lean , new larger Injectors and I got fuel to burn now .
 

·
Premium Member
Joined
·
985 Posts

·
Registered
Joined
·
496 Posts
Discussion Starter · #12 ·
I'm sorta down the middle with the fuel lines, stock is 5/16, unless you've measured for pressure drop at higher idcs you'd really be guessing if larger is needed. With 60% duty cycles on 80lb injectors I doubt there's more than a few lbs of drop, not even measurable in flow. But yea, start pushing more flow with longer idcs and pressure will drop. Larger line will help but almost immediately I'll need a bigger pump, 5/16 line and a 255 Wally is a pretty happy pair.

I checked out the bosche 72lbs but price wise I can get 8 80lb seimens for 430 shipped, that's about the best out there. I've scaled in the 80's on plenty of srt4s and they're just as tuner friendly as any other injector.

Thx guys, been very helpful. Btw, side note, any srt4 injector is direct fit, there's plenty of options out there from ficc, dweschwerks, agp, etc.
 

·
Straight Up Beast SON!!!
Joined
·
17,142 Posts
You will be surprised how much volume will flow with just a upgraded fuel line. Even going from 5/16 to 3/8 Or a -6 would improve the flow greatly. Maybe try that before buying new injectors. IMO that should be done either way when S/C the vehicle..

Good luck
Scott just curious as to what size the stock fuel line is on an LX car as compared to our Jeeps? Would you know?
 

·
Premium Member
Joined
·
17,169 Posts
FWIW..... my injectors are at 74% Duty Cycle at 865rwhp with the Ford 80's. Just a little knowledge being dropped on y'all.
 

·
Premium Member
Joined
·
260 Posts
Thx, these require spacers too right? Intercooler already sits right on the passenger rail, pushing it up another 1/2" caused you no issues?
I have ford 80s and with the spacers there is still clearance between the after cooler and the hood
 

·
Marathon Man
Joined
·
3,229 Posts
Twin 255 Walbros on the stock jeep fuel line setup with 80lb injectors could make 1000hp if you wanted.
I'm doing twin 255's with the 80's. I don't plan up upgrading the fuel line.
 

·
Registered
Joined
·
673 Posts
In my TT WS6 I run 2 walbro 340's, one always on and the other on a Hobbs switch triggered for 4 psi. I can switch the circuit so one pump doesnt get all the use 24/7.

Do you guys run them staged like that or are you running them full blast all the time.
 

·
Registered
Joined
·
11,229 Posts
In my TT WS6 I run 2 walbro 340's, one always on and the other on a Hobbs switch triggered for 4 psi. I can switch the circuit so one pump doesnt get all the use 24/7.

Do you guys run them staged like that or are you running them full blast all the time.
Yes twin 255's with a 3 psi hob switch Stage 6 provides .
 
1 - 20 of 28 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top