ewainwright

I know that there is no real safe amount of boost over stock; however, what are your experiences on running 18 psi on pump gas? Am I asking for trouble or will I be ok? Thanks in advance

porshhhh951

i have yet to have any real problems of any sort......i ran 18 psi for the duration of my d.e. events and pca get togethers.....as well as the street everyday(i drive my car everywhere including to go grocery shopping) i just recently got methanol/water injection ......but, i can tell you i didnt need it.what type of fuel system do you have....i see your 75lb injectiors but, how are you adjusting the fuel??(i use power perfect) also what type of air/fuel ratio do you currently have...and @ what boost level?

fast951

Boost must be considered based on the timing you are using.

More boost on pump gas requires appropriate (mild) timing... The knock sensor does a good job at pulling back the timing, but this is not the correct way of doing it...

Check with your chip supplier to see what they recommend...

ewainwright

Thanks for your response. Other than idle (cells 205,305,405,505) and start up (605), I am at 12.9-12.5 when wot. Other than that the computer is constantly adjusting the A/F ratio. To actually adjust my fuel pressure I have a raising rate adjustable billet (Bosch), sold by Windward (I don't recommend them).Thanks again

Edit Thanks fast951 (All we need to do is to think of you and you respond) :-)

Perry 951

With your setup, 18psi will be fine. Are you running a stock wastegate or the wide fire? Chances are that you will not have a problem, but a little knock can take out the stock one pretty quick.

fast951

ewainwright,
If I understand this correctly you are talking about adjusting the fuel.. How about the timing?

ewainwright

Thanks again for your reply. My car still has a stock headgasket and a stock shinned wastegate. I'll be replacing the head over the Christmas New Year's vacation. I have nothing to control the timing. What do you suggest?

fast951

There are many ways to control the timing, however since you already have a MAP kit (I'm not sure if it handles timing), you are pretty much limited to mods to the chip.

Whichever chip you have, check with the vendor and get their opinion... You might get lucky and they have a timing retard set on the FQS...
Meanwhile stick to 15psi..

When refreshing the head, you might want to consider O-ringing it... Especially if you intend on running higher boost.. Also a Wide Fire Ring gasket is a must...

B951S

I ran 18psi with a MAP on my S, not for long though, but had no probs. I ran 18pai on my older K27/6 and flogged it to death, for about 2 yrs on stock injectors and an FPR. It lived but I felt sorry for it

Fast, THe MAP dosn't do timing retard. The stock timing has a dip of about 5 degrees in the midrage and then max's out at about 23 degrees for the run to the red line. If using a stand alone, would I want to follow this or change it.

ewainwright

Thanks for everyone input

I-Wana-951

Would adding octane booster be better or worse for running a higher PSI? or does it make no difference.. You guys were saying something about knocking and i no adding octane booster possible iliminates this, but i dont no how it is related to boosting in this particular situation.. I was JW so any 1 correct me if i am wrong

keith

Perry 951

Um... I have never heard of any stock chip that is pulling 23 degrees of timing. 19 is the most, and that is with the FQS set at -2.7 degrees. 23 degrees of timing on a stock setup should heat the exhaust enough you would end up burning them expensive sodium filled valves and knocking ring lands off the pistons.

Fast.. you know my answer to to the timing control, but you won't let me get my hands on it. The SMT-6 sounds like it is the way to go right now, short of stand alone.

ewainwright

I have to give credit where credit is due. I emailed Danno and he immediately responded back!! I'll be ok. Octane boost doesn't do anything in my car. Toluene however makes Baby want to jump up and change lanes when full boost hits :-)

Ski

Toluene is good but Xylene is 117 and cost the same, well where I live. You can use less of the Xylene to get good results.

944x-rated

where can you get xylene or tuluene at? is that just a type of race gas, or a chemical you buy and put it in the tank?