fuel pressure regulator - adjusting

[jimnielsen]

I have the impression that you can adjust the standard 2.5 bar fuel pressure regulator to give 3 Bar. Does anyone have any advice or preferably pictures on how to do this - and the procedure - where to put the gauge etc..

thanks, JimN~

[jimnielsen]

Has anyone had any experience at using 'after market' fuel pressure guages / regulator comos such as this one..


360053191569


on ebay? I'd like to be able to easily adjust the fuel pressure.

[pavs]

that is the same as mine works fine :smile:

[axaQ42]

The original one can be adjusted with no problem.There is a screw on the top of the regulator under the seal.Aprox. 1 turn gets 0.5 bar ...but that's just APROX. you need to put a pressure gauge for liquids.

Here is the way how to adjust it by the manual.
http://www.berlinasportivo.com/Technical/q4manual/Q4fuel.pdf..just go to section 4-32

[jimnielsen]

Thanks - can you remember if you turn it clockwise or anticlockwise to increase fuel pressure? I hope to get an inline gauge today.

jim.

[Juan AR155Q4]

You have to turn it clockwise so that the spring is more tensioned.

[jimnielsen]

I've now put in a fuel pressure gauge, and checked that I can indeed adjust the pressure with the original fuel pressure regulator - yes it works fine! Now I will be able to adjust the pressure for use with different maps.

Also in the photo with the gauge is pictured the wide-band Lambda sensor electronics so that I can make sure I don't blow the engine up - or at least see why I blew it up....

The other picture is an "Ostrich 2.0" connected in where the ECU chip used to be. I have tested that I can swap maps on the fly with this thing so it will be a useful device for quickly changing the ECU software!

I am going to test the whole system out this weekend at Sandown raceway in a local Alfa Romeo club race.

cheers, Jimn~

[WhizzMan]

Nice setup, let us know how useful it is.

[jimnielsen]

I raced the Q4 at Sandown raceway in Melbourne today using some new software. As you can see from the graph, boost is now steady at 0.9 bar throughout the rev range in 2nd, 3rd, and 4th gears. The new software has transformed the cars performance, as with the standard software boost drops off very quickly with rising revs (see my other posts for data on this...). With this software its 0.9 bar all the way. I could not collect any Lambda data due to "technical difficulties" hope to resolve that soon... Elsewhere in the data (not shown here) you can see that boost will go to 1.1 bar but only at quite low revs that you just don't normally see on a racetrack. As the car goes much faster now the handling problems become even more pronounced (hopefully to be addressed with the D2 suspension). Also braking is affected, Sandown is a course that is hard on brakes, and after 4 laps of flat out fade became a real issue - but its possible that this can be addressed with some simple ducting. best -g's (ie braking) was -0.9889.. not too bad for a car with street tyres. Video to follow.

Cheers, JimN~

[cuore_sportivo_155]

did you get the brake bias valve sorted in the end? it makes a big difference...

[jimnielsen]

No, I haven't looked at the brake bias issues, I sort of forgot about it with all the other stuff I was working on. The car has quite pronounced nose 'dive' when braking HARD from 200km/h so it puts a lot of the weight on the front - I'll have to go back through the forum and see if I can re-find out what I should be doing.

Another problem that I'd like some help on is with the handbrake. The adjuster at the handbrake lever works nicely, and I've got it adjusted so that there is just a few clicks till it pulls tight - it feels great - but there is no actual braking effect on the rear wheels. I need it to work so that it is easier to park it in position on its trailer. Any ideas anyone?

The clutch is still sticking in the "in" position sometimes - I think its because I have allowed too much pedal travel.

[cuore_sportivo_155]

my guess is your rear brake calipers are seized, possibly on the sliders... this would explain the handbrake pulling tight but not working and the brake fade at the front... up to 30% of the brake effort can be done on the rear if set up well...

[WhizzMan]

seized brake-balance adjuster and rear calipers are *very* common on skinnies. The balance adjuster hasn't changed, but the calipers on the wide-body are slightly less prone to this. If you're going to put this car on the track only, get some other calipers without hand-brakes and if you require a hand-brake, put a hydrolic one on.
Otherwise, get a complete rear-brake kit from a wide-body. From what I understand, getting 155 parts in Australia can be challenging, especially if you want second hand stuff, but I'm sure people in europe will be able to help you search.

Also, have you checked the rubber silent-blocks in your lower wishbones in the front suspension? Once these start giving your car is all over the place and because of the toe-out you get when braking...well, you get where I'm going. for track use, I'd reccomend getting PU replacements from superflex or powerflex, actually, for road use too, just for the durability alone they're worth it. :)

[AlfaJack]

Also, go on to alfa155.org and get in on the second group buy of these for the front ARB drop links:

http://img340.imageshack.us/img340/787/16584291db1.jpg

http://alfa155.org/forum/viewtopic.php?t=17872

[jimnielsen]

Thanks for the advice Whizzman - I really would prefer to retain some form of hand brake if I can. There is * NO * chance of getting any 155 parts here - least of all wide body ones. I have read the manual now about how to adjust the hand brake (and I haven't actually done ANY of the stuff like.. taking the cables off the calipers and pressing hard on the brakes 10 times etc.) So I'd better try that first before I throw the 'baby out with the bathwater'. I have Powerflex bushes on all the lower front suspension wishbones. Also I havent done the bit about adjusting the rear bias with the 5kg weight - so l'll do em both this week and see if it helps!

thanks again.

Jimn ~

[wrinx]

The rear bias is supposed to make a huge difference...still need to do this on mine as the rear discs are going rusty!!!

...job for this afternoon possibly :)

wrinx

[WhizzMan]

Also, go on to alfa155.org and get in on the second group buy of these for the front ARB drop links:

http://img340.imageshack.us/img340/787/16584291db1.jpg

http://alfa155.org/forum/viewtopic.php?t=17872

I am ;)

[cuore_sportivo_155]

Also I havent done the bit about adjusting the rear bias with the 5kg weight - so l'll do em both this week and see if it helps!


experiment a bit with different weights, and you could set up the rear brake to aid in trailbraking. Love that on mine :) I have atwinny, but I used about 8kg weight iirc...

[BRUNO 57]

Somebody can confirm "If i turn clockwise (without gauge ) i can make 1 turn to have 0.5 bar more without probleme to have approximativly 3.0 bars fuel pressure ??

[Stuntz]

Yes that is right but its aporximatly you shuld messure it as it is described in the manual.

[jimnielsen]

Bruno, I had to turn it 3/4 of a turn to make it 3.0 bar at idle.

jimn~

[BRUNO 57]

Thank's a lot at all!! for your answer EXPRESS!!
-have a good ride this sunday
-CORDIALY AT ALL BRUNO