Tuning stuff and advice, please

[turbopete]

I have recently seen the WOT O2's lower. Trying to figure it out. Did a few freeway runs (40-90) and had Scanmaster recall O2 at 650-680. KR was in the range of 1.0 to 1.5.

Raised the fuel in the chip 10% across all RPMs. No change.
Raised fuel pressure from 45 to 48 (line off). No change.
Raised alky from 6 to 8. No change. (It is using the methanol).

Single nozzle alky
Eric's 5.6 chip
Old walbro fuel pump, hotwired

I don't like freeway tuning, but want to make sure the car is properly tuned for fun.

I think the next steps are:
Put a gauge line on the fuel rail to make sure the fuel pump is not falling off under boost. May be time to replace the pump anyway...
Update and run the Powerlogger (with a copilot).
Wideband O2.
Dyno runs.

24 PSI (minimum with this turbo)

Thanks.

 

[Boost231]

so are you saying your getting the same amount of knock everytime as well as the 02's staying the same or

is the o2's staying the same regardless of your changes? why not change the 02 sensor out?

 

[turbopete]

O2 Sensor

It is only about a year old, but it is one of the things I could change, just to check.
I am concerned that raising the alky alot (6 to 8) did not make a significant change to the O2. With that much more alky, the O2's should really go up, right?

 

[djj624]

My bet is on the fuel pump. Throw that gauge on it and check fp throught the run. Your fp should be about 67 if your fpr is set at 43 wich i think is what erics chip calls for as a base setting.

 

[Boost231]

yes 02's should go up with the change in alky. Did the knock go away when you turned the alky up? in my brothers car he had and o2 in there for not even a 1000 miles and it went bad over night.

 

[1chance]

Well i will put my 2cent's in. I have been trying to get the tunning for a while! I learned how to build my own engine, and trans, now in in tunning class. Anyway Ive learned the cam sensor effect's fuel alot! My car has a bigger cam, so i had to advance mine a good bit, if not O2s would be very low with alittle KR, then i found out today that Eric suggest to start FP at 43, them adjust +/- 3,4 psi. I set mine on 43 thinking that's where it should be(not) car was idleing like it had a 3/4 cam in it for 6months, and i was thinking it was the MAF, well changed it, and car still idel rough. So i for the first time bumped FP to 45, and the car idle alot better, but had to retune the whole car all over. Hope this help, i to was adding 10% more fuel, but had to take all that back out, good luck.

 

[turbopete]

Knock

The knock has been less than 2.0, but obviously I am looking for zero.

Will start with the O2 sensor, just to make sure the O2's are reading correctly.

I think I can borrow a fuel gauge from Steve V, when he gets his house stuff settled. You say that the Walbro 340 should read a steady 67, but I am just looking for pressure drop-off under boost, correct? May just replace it with the new style one from Full Throttle. That pump is original, I think...

 

[Boost231]

the pressure so read as follows. if its at lets say 39psi with the line on you want while crusing. when you get into boost you want it to raise 1psi for every pound of boost. so say your running 20psi of boost the fuel pressure at this level while at WOT should be 59psi

 

[turbopete]

Fuel pressure

Ah, I see.
40 PSI line on plus 24 PSI boost = 64 PSI at WOT.

A good place to start.

Thanks.

 

[Boost231]

correct.