Hi i am going to push 8psi out of a t3/t4 turbo on my 2.2 cavalier ecotec 2005. For now i have a 10:1 ratio vortech FMU.
Will it be enough to run with stock injectors & fuel pump?
For a "mechanical tune only", for now, what would you recommend to change on this setup to maintain a rich-stoich mixture under boost? (please provide mechanical stuff only for this setup & question)
However, i plan to order HPTuner after, to tune it on my own.
With the fact i will have hptuner, and lets say i have my car all back to stock parts :
- will the stock pump do the job with decent injectors (310cc - 650cc) ?
- what injectors exactly would you recommend to use that will fit rail in length & size (could you provide name/part number/spec or any info that would help)
- do i need to change the stock fuel pressure if i tune with hptuner or VE tuning & injector const do it all?
- is the stock fuel pressure regulator going to increase the fuel pressure under boost?
Any info with parts recommendation will help, especially if the parts name/numbers are provided.
Any experience you have with custom setup would help too. Id like to hear about it!
Thanks a lot
Stock injectors need to go ...they wont be able to support anything past stock with a tune. Stock cobalt ss or stage 2 injectors can be had on the cheap. Also you wont get much more than 220whp out of a stock pump unless you throw a harness upgrade on it to deliver more voltage off the alternator.
How much more room is anyone's guess without monitoring duty cycle. Also pick up an adjustable fuel pressure regulator to change your base fuel pressure.
FMU's work for fueling, but what about spark? How are you going to retard timing when in boost on your mechanical tune?
FU Tuning
JUCNBST wrote:Stock injectors need to go ...they wont be able to support anything past stock with a tune. Stock cobalt ss or stage 2 injectors can be had on the cheap. Also you wont get much more than 220whp out of a stock pump unless you throw a harness upgrade on it to deliver more voltage off the alternator.
How much more room is anyone's guess without monitoring duty cycle. Also pick up an adjustable fuel pressure regulator to change your base fuel pressure.
What injector size would you recommend with 10:1 ratio FMU?
What is the Adjustable fuel pressure regulator for? to adjust idle pressure when not in boost because of the bigger injectors?
Do you know what max fuel pressure the stock pump can go?
Addicted to meth wrote:FMU's work for fueling, but what about spark? How are you going to retard timing when in boost on your mechanical tune?
i know Hahn race craft is kind of this setup, and they don't use any "timing tune" and seems to work great for most of people who bought this kit.
What do you suggest?
Bump (only because i am new & dont know if anyone got noticed with my 2 replies)
I'm running the Hahn kit and I use the BEGI fuel pressure riser with 32lb accel injectors with an airtek inline fuel pump and different plugs with a "mechanical tune"
Connor Sobotka wrote:I'm running the Hahn kit and I use the BEGI fuel pressure riser with 32lb accel injectors with an airtek inline fuel pump and different plugs with a "mechanical tune"
Is it running well?
What is you idle fuel pressure? What did you do to adjust your idle with bigger injectors?
The only mechanical tune you have is the BEGI thing on the fuel return line?
Thanks
Vincent Roy-C. wrote:Addicted to meth wrote:FMU's work for fueling, but what about spark? How are you going to retard timing when in boost on your mechanical tune?
i know Hahn race craft is kind of this setup, and they don't use any "timing tune" and seems to work great for most of people who bought this kit.
What do you suggest?
Yeah well Hahn will also tell you 14:7:1 AFR is good on 7psi.
I know plenty of people who have used stock timing on boost, but it is not smart. Timing needs to be pulled when running boost.
I do not recommend mechanical tunes.
FU Tuning
Addicted to meth wrote:Vincent Roy-C. wrote:Addicted to meth wrote:FMU's work for fueling, but what about spark? How are you going to retard timing when in boost on your mechanical tune?
i know Hahn race craft is kind of this setup, and they don't use any "timing tune" and seems to work great for most of people who bought this kit.
What do you suggest?
Yeah well Hahn will also tell you 14:7:1 AFR is good on 7psi.
I know plenty of people who have used stock timing on boost, but it is not smart. Timing needs to be pulled when running boost.
I do not recommend mechanical tunes.
With fact i am going on hptuner after a mechanical tune : what do you by timing needs to be pulled? Crash course 101 on timing, generally the timing should be advanced or retarded? Does it have to do with the current afr when tuning?
Thanks
Vincent Roy-C. wrote:Addicted to meth wrote:Vincent Roy-C. wrote:Addicted to meth wrote:FMU's work for fueling, but what about spark? How are you going to retard timing when in boost on your mechanical tune?
i know Hahn race craft is kind of this setup, and they don't use any "timing tune" and seems to work great for most of people who bought this kit.
What do you suggest?
Yeah well Hahn will also tell you 14:7:1 AFR is good on 7psi.
I know plenty of people who have used stock timing on boost, but it is not smart. Timing needs to be pulled when running boost.
I do not recommend mechanical tunes.
With fact i am going on hptuner after a mechanical tune : what do you by timing needs to be pulled? Crash course 101 on timing, generally the timing should be advanced or retarded? Does it have to do with the current afr when tuning?
Thanks
Since our cars were n/a from the factory they have a different timing advance. normally you get more timing n/a. When you add boost you need to take timing away.
FU Tuning
It"s ran great since 12,000 miles ago when i put it on at 142000
. Its running 35 psi at idle at about 900rpms and 90-95 psi at 9lbs. The BEGI uses an idle screw on top and the fuel pressure rises via a vacuum line from the turbo to a screw valve on the BEGI. The screw valve is what you use to adjust fuel pressure under boost.
mechanical tune is asking for it to blow up...
Vincent Roy-C. wrote:
With fact i am going on hptuner after a mechanical tune : what do you by timing needs to be pulled? Crash course 101 on timing, generally the timing should be advanced or retarded? Does it have to do with the current afr when tuning?
Thanks
By pulled he is referring to retarding the timing. While AFR has some impact on your timing advance, it has more to do with cylinder pressure and temperature which are both elevated in boost.
Does throttle position sensor affect timing under wot? I'm asking because when I did my 5-speed swap the tps plug had to be replaced on the manual harness and when I replaced it I messed up the voltage due to too much solder
. So I have a check engine for low voltage at the tps sensor. Does this effect my timing?
It would affect how the computer commands the delivery of fuel under all conditions, our ECU's reference TPS to RPM to calculate fuel requirements. You need to have things like that fixed before you build your motor. Seemingly minor things like that can be the difference between a good running motor and motor parts all over your garage.
I do need to take care of it but I've tried... I've tried resoldering the plug, changing the plug, and sensor. I can't figure out why it keeps coming up.
