Ok so the other day i decided to change the spring in my wastegate. I noticed my boost gauge is only hittin between 5-6psi. I did a boost leak test and found air seeping from a coupler. So i fixed that, took it down the rd and im still only hittin 5-6psi. I do have an fic in the car and i was talkin w a buddy of mine and he said that maybe the timing could be affecting the boost pressure. I only have it set retard the timing about 1 degree per psi. Any thoughts????

 

you put a softer spring in it sounds like.

 

Its def an 8psi spring. I tested it by pullin vaccum from the top of the wastegate. Its began to open @ aprox 16in hg which calculates to around 8 psi. So its def not the spring. I tested the boost gauge and it works fine. Im gonna try changing that stupid nylon line they give u to silicone and see if im losing it thru the line. I personally dont think that its the line cuz of the fact that its reading perfect vaccum (doesnt mean its not the line tho) im just tryin to figure out if its the timing or not or if neone else has come across anything similar.

 

first question i have is..........what are you using for a vac source for your wastegate? my guess is your using perhaps a vac block and have a line running from your vac block to your wastegate. if thats the case go strait from your turbo to wastegate.

 

did you take it back appart and reassemble it? what was your old spring? you could very well have a 2psi pressure drop in the system. i have a 8psi spring and it never read 8psi on my gauge. until i put a MBC on my car. but thats just my experience.

 

i need to do this myself actually.

 

i do have it run off a vac block. But no disrespect i doubt that would be the cause. The wastegate is opening so the vac source is ok. Plus theres no vac leaks from the block at all. And also just from my experience, running the vac line right off the turbo will give incorrect boost readings.

 

i had a 4spi spring in the there before and it read perfect on the gauge. Im thinking the same thing about the mbc. I may go this route and see what the outcome is

 

That will give it the most accurate readings.

Did you get larger injectors yet?

 

Nah mike i havent gotten larger injectors yet. I need to soon. Lol. I either gotta sell off some stuff first or gotta wait til i save enough $.

As far as my boost issue goes, im gonna pull the car in and do another leak test just to make sure that i didnt miss anything.

But what i really need to know is about the timing on the fic. Will it in fact not make as much boost as it should if the timing is retarded too much? Im just tryin to cover all my bases other than the obvious.

 

Unless your timing is WAY out there its not going to affect your boost.

Be careful with those stock injectors

 

Yeah i know. The good thing is that im not runnin lean. Im readin between 11.5 and 11.8 @ wot in 3rd. I only have the timing retarded 1 degree per psi thru boost on the fic so i honestly dont think thats it but i just had to check.

 

now that i think about this my car did this too when i first boosted it turned out to be caused by my fuel pump going out.

 

Also idk if me using the stock mid pipe and s pipe would have anything to do with it.

 

Just get a MBC.... I wouldnt want any more boost than that with stock injectors...when I had 410cc they ran high IDC at 7 psi

 

no disrespect taken. but from personal experience having the vac line ran from the turbo gives the most accurate boost.....also.....its safer. takes less time for your wastegate to open once you hit your spring rate.

 

yes it will. the stock spipe is to restrictive your turbo starts pushing ar and then all that air cant move fast enough because of the back pressure caused so you lose boost. i had the stock Spipe for a minute so i really should of said in my post about my fuel pump it was a combination of things stock spipe and midpipe playing in to the factors.

 

What kit you have? The air may be leaking from the back side of the compressor as well.

 

stock mid pipe is a bit of a restriction but not as bad as the stock axle back...stock axle back would not allow me to reach wastegate spring pressure. It dropped boost 1psi-2psi less than wastegate spring (using 8.7psi spring).
I would take a look at your diaphragm on your wastegate. make sure you havnt pinched it or torn it. trust me when i say its easy to do plus it will affect boost.
exhaust leaks before turbo can do it aswell, so make sure your mani is german (good and tight).
also get a datalog with your fic and double check your boost level, just to see what it says. Alot of times when im tuning I cant hardly tell what my max boost was untill i check the logs. mainly cause my boost gauge reads in whole numbers so you never can tell the exact amount.
what was said from others about vac lines is 100% true. You want a strong and clean boost signal. If using a vac block tap your brake booster line for it BUT run a fuel filter inbetween your vac block and booster and if your feeling froggy put a small fuel filter for all of your vac lines comeing off the vac block. Trust me I have never seen such a clean signal till I seen someone put filters on all their vac lines.

http://www.monsterscooterparts.com/f...version-5.html

the filters act as a damper so when you have vac/boost actuated hardware doing what they are supposed to they dont muddy up the vac/boost signal.
This was suggested to me from the guys at p-tuning and ill be damned if it didnt work like a charm. This is just to clean the signal so that your data logs dont look like scribble. It can also help your bov from wigging out on ya (open and close rapidly).

 

good point! alot of turbo comp housings are not sealed properly or when they are clocked the seal gets screwed up.