boost woes

[2 stroke man]

i need some help guys. i mentioned awhile back about my turbo not boosting much lately. my EGTS are staying high, and my boost will barely hit 20 poundsfor a brief time with a moderate load, in drive, to the floor on a hill at 70 mph with 3,000 rpms. cruising with a load, i'm lucky to make 5#. any ideas? hopefully the turbos going bad, to make way for a new one =). but, no shaft play, and my compressor wheel is nice and smooth. with just 6,700 pound trailer cruising along my egts are hittin 850* in od.

[c00nhunterjoe]

20 psi is really good for your mods, its all i can do to touch 20 psi for a split second and i have to hold mine in gear to almost 3400 to even try.
- wot in mine at 3000 rpm is roughly 15-18 psi
-towing a load in od means low rpm's. 7k at low rpm and only hitting 850 is really good as far as i'm concerned.
- cruising with or without a load i make basicly no boost, the gauge wont climb till i am on the throttle down geared.
- only time i get boost on a cruise is 70-80 mph on light hills, i can build 5-10 psi but the rpm is up between 2000(70) and 2500(80) at that point.
- 55mph is 1500 in my truck, that = 0 boost for me.

[c00nhunterjoe]

just noticed teh signature----- leaky up-pipes cause low boost and higher egt's but your numbers dont really sound bad

[MADVAN]

Agree on the leaky pipe thing.
On another note check your idle and wot fuel pressure.
I remember you having an issue with FPR.

Bill

[2 stroke man]

i checked pipes the other day. they were tight. i unplugged my MAP today, it seemed to run better unplugged

[foxracing0934]

I dont know, i have a similar set-up to you and i can get between 25-28 psi. I wonder if it could be a leaky up pipe? Less exhaust gasses meaning less spool up.

[Robbgt]

Originally Posted by foxracing0934

I dont know, i have a similar set-up to you and i can get between 25-28 psi.

With stock injectors?? what setting is you DP on??? That some boost from stock sticks! Like c00n said, most are happy with 20ish from stock sticks...

-Robb

[foxracing0934]

ya i have stock injectors, 4.10's, and in the 80 horse setting i can get like 26 psi, on the 120 setting i can get like 27-28 psi. And i'm soon getting stage 2 DIY's!!

[Robbgt]

Originally Posted by foxracing0934

ya i have stock injectors, 4.10's, and in the 80 horse setting i can get like 26 psi, on the 120 setting i can get like 27-28 psi. And i'm soon getting stage 2 DIY's!!

Wow good stuff man! careful with those 2's.... start creeping up on 35PSI IIRC and the stock turbo is toast... you can talk to TJ about that...

-Robb

[foxracing0934]

Y i read on here somewhere that you can run 35psi but only short bursts. Its ok i plan on an H2E and a Spearco 6.0 intercooler from black widow. My only fear is that i will soon be into head stud range..... and i dont want to do those.

[c00nhunterjoe]

is your truck a cali emmisions unit? 30 psi and 120 dp settings with no cel is odd for a 49 state truck

[foxracing0934]

I dont know if it is or not, it could be because i needed to get a new part for it that was only on the cali truck but Rob posted a picture for me that was describing a cali truck and my truck didnt have that part on it. (A diaphram off the fuel pump maybe???)

[Todd525]

Everyones gagues read a little differently, if he is hitting a TRUE 25 plus, he has one of the BEST running OBS in the country on stock sticks, we all know that.

2 stroke,
Honestly, empty on flat ground, stock sticks with ANY programmer you should see 1 to three pounds of boost, and EGTs should be 600to 650. Now this is with a GOOD set of gauges, and the sending unit IN the manifold, NOT in the pipe itself. That will throw you WAYY off. If your sending unit is in the drivers manifold, right at the rear of it where the flat spot is, then you are running REALLY well as coon said. Honestly with that weight in OD you should see about 1000 to 1050 if you have a 4.10 auto truck. If your seeing those numbers ( your 850 ) and you have the sender in the correct location, I would start looking for a new gauge.

[Neal 97 250]

I used to be able to touch on the 25 psi boost with my stock sticks. Had to run it pretty hard to do it though. 22-23 was pretty easy.

[tjbeggs]

My 95 which was pretty much stock with TEE5 programming (stock) hit 20 psi empty. I was amazed when I measured it. So I took my tymar, fuel pressure shim, and 10K mod off and still hit 20 psi. its possible.