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Discussion Starter · #1 ·
okay, so i got my new t28 all back on, and now i think im having problems with my wastgate... so far its only boosted to 21 psi, and under WOT, in higher rpm's, the power just dies abruptly and makes a werid noise, i cant even explain it. its like a really quiet, super fast backfire almost? is this the sound of the wastgate opening prematurly??? should i order the forge one from genuine or just get a new oem one???

ben
 

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saab_family said:
okay, so i got my new t28 all back on, and now i think im having problems with my wastgate... so far its only boosted to 21 psi, and under WOT, in higher rpm's, the power just dies abruptly and makes a werid noise, i cant even explain it. its like a really quiet, super fast backfire almost? is this the sound of the wastgate opening prematurly??? should i order the forge one from genuine or just get a new oem one???

ben
knock?

if the wg open you will see the boost drop, does it?
 

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Discussion Starter · #3 ·
Vigge said:
knock?

if the wg open you will see the boost drop, does it?
ill go for a quick spin and check. knocking is really bad isnt it? what causes it and how do i fix it??:cry::cry: water meth?
 

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saab_family said:
ill go for a quick spin and check. knocking is really bad isnt it? what causes it and how do i fix it??:cry::cry: water meth?
Yes....

Do Not Want.

Is this the same turbo you had before, or have you upgraded?
 

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saab_family said:
okay, so i got my new t28 all back on, and now i think im having problems with my wastgate... so far its only boosted to 21 psi, and under WOT, in higher rpm's, the power just dies abruptly and makes a werid noise, i cant even explain it. its like a really quiet, super fast backfire almost? is this the sound of the wastgate opening prematurly??? should i order the forge one from genuine or just get a new oem one???

ben
Sounds like either there is something wrong with the turbo after the re-build or something wrong with you're car. Disconnect the W hose and see if it just pops right up to 25psi or not and that could mean either boost leaks or a problem with the turbo. If it boost fine with the w hose off, its a bpc, ecu or other problem. Check you're a/f ratio too! This could help you eleminate waste-gate issues. Can you tell where the noise is coming from?


It could be going lean, I have replaced 4 fuel pumps in 3 years! The only way to know is check fuel pressure or a/f. My aero would surge and dump boost too because it was lean! I have the innovate portable now, I could put it on you're car and check the a/f under boost!

You had a helper spring and that can make the base boost whatever you want. I used to set it from 7psi to 9psi and would get spikes to 29psi on cold days. You can bring it buy sometime if you want.

Check all the basics, clean the plugs, replace the plugs, bad gas will do a lot of bad things up here. A bad di will also cause poor performance. Check all the basics and test the waste-gate and see whats up.

John
 

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Discussion Starter · #6 ·
well hum. i havent gone out to check it psi drops yet. but its the same turbo i had before, what jak calls a big t28 or whatever, we just got a brand new center section from our garret distributer, and put it back together with the old housing. i havent gone out to check it psi drops yet, but its old gas (91 thats been sitting in the tank for about 3 months) ill go fill it up with fresh 91, check the plugs and everything. it pulls pretty hard though, espically for only 21psi! so i dont know whats up! iv got the orginal fule pump as fas as i know with 123k miles, maybe i could use a new one... i dont have any way to check my a/f so if its still doing this after i check everything ill stop by john if thats cool.
 

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You should definetely check you're a/f. Every single car I have checked has had a weak fuel pump! Give me a call and we can set it up. My ng900 and my aero and my roomates 9k.

John
 

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Discussion Starter · #8 ·
ok, boost does not drop when it does it. ill call you sometime soon john, it might be a couple days though because i have work and and a lot of homework to do....:evil:
 

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Yea, I have a couple of spare di's and the wide-band portable lm1 we can throw on you're car and check a/f under boost. Give me a call sometime and you can swing by and I will check it out for you,

John
 

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John Z Williams said:
Yea, I have a couple of spare di's and the wide-band portable lm1 we can throw on you're car and check a/f under boost. Give me a call sometime and you can swing by and I will check it out for you,

John
Another example of the Saab community at work! Good on ya. I hope you guys get it figured out.
 

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Discussion Starter · #11 ·
thanks a bunch john! liketheword, you have no idea how cool john and how helpful he is, my car would not be at the levle that it is with out his help. im wondering if it is the fule pump, it only does it in high rmps (past 4.5k under wot) and, im by no means an expert, but it "feels" like its loosing fule
 

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That is easy to check and we will know right away. I am putting in the walbro 255 high flow fuel pumps now. They are about the same price as the stock oe and will flow more and give some extra safety margin.

John
 

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John Z Williams said:
That is easy to check and we will know right away. I am putting in the walbro 255 high flow fuel pumps now. They are about the same price as the stock oe and will flow more and give some extra safety margin.

John
if you have not bought it (them) yet, buy the bosch one(s) instead since it holds up flow to higher fuel pressure than the walbro one does.
 

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Vigge said:
if you have not bought it (them) yet, buy the bosch one(s) instead since it holds up flow to higher fuel pressure than the walbro one does.
I can second that from my domestic days. For the sake of reliability we ran dual Bosch pumps on Mustang GT's that were supercharged.
 

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Vigge said:
if you have not bought it (them) yet, buy the bosch one(s) instead since it holds up flow to higher fuel pressure than the walbro one does.
I have heard that, but they were over twice as much at about 230.00 to 299.00 a piece and the walbro is showing good results on a/f so far, have not tested fuel pressure again,

John
 

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John Z Williams said:
I have heard that, but they were over twice as much at about 230.00 to 299.00 a piece and the walbro is showing good results on a/f so far, have not tested fuel pressure again,

John
I have run the walbro few years in my car (did not know better at the time...) and I have nothing to complain, but was just pointing out that in case you want to play it "more" safe choose the bosch.
 

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Vigge said:
if you have not bought it (them) yet, buy the bosch one(s) instead since it holds up flow to higher fuel pressure than the walbro one does.
I agree with you and I will put a bosh in my ng900 with 450-500bhp, the stage 3 9k will keep its walbro 255... Since I have a wide-band on it all the time, I will know if it goes south again;)

John
 
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