Tuning a car last night 09 with fic.

First i tuned the car to 9psi!

he drove like that for a couple days no issues..

Turned it up to 11.5 no issues made great power!

So He calls me last night saying it went to almost 12.0 afr at redline!

So imediatly i have him meet up with me so we can check it out! His aem true boost was spiking to 12.6 psi!

But he said its only been doing this when its really cold!

Ok no biggie ill just tune it 13 psi so there never any issues.

Yea yea pretty much the combo of stock fuel pump and 550s hit the wall

Never delt with this issue since most people at least upgrade there pump!

Ive lowered the boost to 9psi again and told him to leave it there untill we figure out best option!


So, Is upgrading fuel pump, or changing injectors, or both the best option here?!

Thanks
all

 

i think hes maxing out the injectors maybe? i know u couldnt get the duty cycle numbers but i think at that boost level and power hes shooting for the FP would be an easy upgrade first

BTW r u free today for a quick phone call?

 

hmm so you think im going to need 650cc injectors for 11 psi? ive got 550cc now i want 300 hp

 

i maxed out my 900s on 8-11 poundss

 

I would recommend changing the pump and seeing how she responds before spending more $$ on injectors.

 

PUMP! when i was at 13 psi with meth i wasn't maxing my injectors. i think i was like at 80 something percent.

 

Elevation u need to upgrade the fuel pump. I tuned my car with Crush at 8psi, 550 injectors at 80ish% cycle and stock fuel pump. It was working alright, but in the top end the the fuel trims would spike a bit too much with the ECU trying to deliver the necessary fuel. Later on I decided to up the boost to 10 psi and that's when I started having problems. My duty cycle sometimes would spike to 100% with steady low 90's.
I bought new 700cc injectors thinking that it would solve the problem, it did to some extent though cuz the duty cycle dropped to high 70's low 80's, but I still had problems with the top end fuel trims. The afr gauge and afr's on the log would look ok, but the car just didn't feel right. Got to pay attention to the Fuel trims.
Yesterday I installed a walboro 255 and now it's working like a dream. The duty cycle dropped to 50's-60's and the top end is working great. Before the pump, Fuel trim logs used to show a lot of fluctuation after 4k rpm towards the lean side. The factory ECU was trying really hard to get the fuel there, but the fuel system wasn't up to the task.
I got a great deal from someone here selling the fuel pump/700 cc injectors combo that Dezod sells, if I were U I would look into that. Deff an easy fix bro, but if u can't get both at least get the pump.

 

im gonna say pump too, it will also improve the spray quality of the injectors.. I never had fueling issues 8-10 psi although my 550s are close to max. Above 10psi it stays on high 11s with me doing lil work on the fuel map, prolly the injectors has gone static

 

i have gone up 11psi before running into problems but you have to think about most peeps are not running the same turbo...diff turbo means diff volume of air, cant just go by pressure.

 

yea.. this is a 60-1..

i just was asking if the fuel pump would help out or not?


thanks guys

 

well fuel pump is normally just a touch over 100 bux and some places just under...its worth a try if you ask me.

 

Haha.. its not my money!

I got two fuel pumps!

this guy is boosting on a budget! you know what happeneds theN!

 

yep...iv done the same thing but i really didnt have a clue how far the stock fuel system would really take me...when i first started there was alot of speculation but not a lot of hard core proof. now i have a better understanding of the stock fuel system because of my own exp plus what others have shared.

 

anyone know the max flow rate of the stock fuel pump? that would prolly help with deciding lol

 

Fuel pump is the first mod you should ever do. EVER. end thread.

 

Reason im asking is because ive herd by just upgrading the pump your still limited to the pressure that the factory fpr restricts!

And he wants the easy way out..

 

Sure he's limited to the fuel pressure of the stock regulator and the only answer to that is a return fuel system however I'm more concerned with the flow capacities of the stock pump vs the walbro.

 

im sure the volume cant change so much since its stock lines. but i would imagine a more steady flow of fuel vs a fuel pump working its butt off! I wounder if at 12 psi, theres any fuel thats even being bypassed into the tank?

 

Probably not considering the regulator in the tank can't vary the pressure it holds it at a steady rate set by the spring. A good pump, return fuel setup and good injectors is the only way to do this.

 

^^^x2. i got 440s at 12psi with return fuel setup and aeromotive reg and walbro, it makes all the difference.