[lunchbox660]

the title says it in a nutshell, but basically here is what is happening. i just installed the W/I today and it is running great, BUT i noticed that when the WI kicks in my boost almost instantly drops a few psi, like 4 psi maybe. i did not change my boost settings AT all, they are still the same as they were from day one. i run 20-21 pounds of boost and it normally drops to about 14-15 at 6200 rpms. well, NOW i am hitting my 20 psi of boost, but a split second later you can see it drop down to 15-16-ish instantly and you can even hear the turbo slow WAY down.

i read something about spraying too much causing the motor to bog down...would this be what they were talking about or does this sound like something different?
how do i correct it?

mods:

intake
3" cutout DP
big fmic
ported polished and clipped stock turbo and manifold
ported and polished intake mani
hard pipes
MAP clamp
WGA and MBC @ 20-21 psi
return fuel setup on stock injectors
devils own base SRT4 injection kit running a 2.5 quart bottle with one bottle of yellow heet, the rest is 32 degree methyl alcohol windhield fluid and about 4 cups of distilled water to top it off. nozzle is an M5.

thanks for any help! im new to this!

[rudebwoy]

maybe your massive pressure drop is caused by the size of you intercooler on the size of the turbo.
I also thinks it has something to do with the density of the air, I am not sure about that part so I'll let the experts take it on.

[lunchbox660]

in theory that sounds normal and makes sense, ive heard of pressure drops before when people use larger intercoolers, but i have had this IC on for over a year and this is a totally new occurence starting yesterday with the addition of the injection kit. the car is still making tons of power, more than it was without the kit, but im just curious about why it wont hold its boost. i did a boost leak check on it to 25 psi and it had no leaks.

last nite i took it out for a spin again and the funny thing is that the boost would drop like i mentioned before, but then i noticed it would begin to slowly climb back up a little bit again after the drop....as the night went by the problem just kind of disappeared. i dont want to just leave it at that and call it a day tho, something was going on with it and i would like to track it down so i know what to look for in the future.

[lunchbox660]

in talking to a few people on the srtforums it sounds like maybe ive got the nozzle in the wrong spot. i mounted it AFTER the IAT sensor because i thought it wasnt suppose to see the cold air temp...some people are telling me otherwise. so...should i mount it BEFORE the IAT sensor then?

[dvldoc]

You can mount the nozzle before or after the IAT sensor, This really only effects how much timming you will get. You should not have a boost drop, at all, infact you should boost up to your max boost much quicker. If your on the stock turbo under 20 you should not be running that M5 nozzle, it's to much.

You should be using a M3, And since you added a larger IC, you would not need so much alcohol. It looks like you are just spraying way to much.

[lunchbox660]

sorry i should have updated the thread. well, after the initial issues i was having with boost pressure now that issue seems to have worked utself out. not really sure how or why, but it has. now it boosts up just fine and holds plenty good like before.

when i originally placed my order i gave a full list of the mods the car had and the M5 nozzle is what was recommended to me. now that the boost problems i was having have sorted themselves out, the car is actually boosting a bit mroe than 20 psi now and holding it pretty well. i would say it is around 21-22 psi, but it IS a mechanical gauge, so we all know how falible those can be...

by putting the nozzle pre-IAT sensor you say it would affect timing....would timing increase/decrease/or just move its curve? so installing it post-IAT sensor should still be fine then?

also, i know you guys get this alot but ive never really seen a whole lot of follow-up discussion about it....what are your thoughts on the effects of corrosion when using injection systems? i am going to cease using the windshield fluid in my mixture and switch up to just a bottle of HEET added to a gallon if distilled water. what effect of corrosion would this potentially have on the internal structure of the aluminum parts such as the TB, intake mani, head and what if any effects would it have on the internals of the engine? i know it cleans things up quite a bit, but are there any negative side effects to this at all?

thank you!

[lunchbox660]

well, i just went messing around with the tune a little bit more. i added some more "heet" concentration to my mixture. basically i have about 3 bottles of heet in my 2.5 qt container with the rest distilled water. this in conjunction with swapping for a different brand of gasoline (still 91 piss tho) helped me to achieve a near perfect street tune. the car is making 31 dgrees timing advance, zero knock count, and AFRs are staying nice and close in the high 10s to mid 11s. i know i could got a little leaner on the AFRs, but it think for now i prefer to leave it where it is just to stay on the safe side. ive already noticed a great increase in fuel mileage with the boost on and the injection kit running, so i figure there should be no reason really why i cant use a teeny bit extra fuel to keep it on the safer side for now. im sure i will get brave later on and lean it back out to high 11s or 12s, but for now on this cali piss, i think i will just stay where i am....lol

race fuel is a different story though....i was able to run 13s with the race fuel and still get zero knock count with the injection kit runnin so OBVIOUSLY this stuff works!

[rudebwoy]

don't you think 10. AFR's is a lot too rich? it may cause more problems than help, you should get it to 11.5 to 12.1 . in boost and about 14.5 in vac. 13.1 transition into boost. if you are too rich you could will wash the oil off the cylinder walls and that could be bad.

[lunchbox660]

i talked to chance @ D/O and asked him about cylinder washing and it was hi opinion that cylinder washing due to W/I is total bull. people have had washout happen on non-W/I cars and with, low miles, and high...it is a random occurence. or at least, that is what he is telling me.

as far as how rich it is running, it is in the 11's now, it just has that high 10 dip when it first kicks in. the way i have the car tuned is such that if the nozzle gets clogged or a line breaks or anything crazy like that, the car will still have enough fuel to run safely on its own until i get out of the throttle. i am not interested in pushing the AFR to its limits and risking severe engine damage when a component fails or clogs. power isnt worth that much to me. i only bought the W/I kit as a means to protect my engine. here in socal we have the WORST gas ever. even with "high octane" 91 (that is a total oxymoron) here in socal, the car is still displaying alot of knock retard and pulled timing. the W/I got rid of that, but i wouldnt want to worsen my situation by running the fuel mixture any leaner than i normally do.

[VR6T]

Originally Posted by rudebwoy

don't you think 10. AFR's is a lot too rich? it may cause more problems than help, you should get it to 11.5 to 12.1 . in boost and about 14.5 in vac. 13.1 transition into boost. if you are too rich you could will wash the oil off the cylinder walls and that could be bad.

14.7 is the perfect afr for boost....