BigTex Posted May 24, 2005 Report Share Posted May 24, 2005 Ben ran a good size cam and ASM headers with his Radix and still pushed 9+ psi I think. My cam is a bit smaller but my exhaust is definitely more free flowing than yours. I'm able to push out 8+ psi with the same pulley that others are making near 10 with. In that regard, I lost a bit of boost, but my end result HP is better because of it. I could feel the gains from cam and headers, but those were nothing compared to the gains I got by slapping the Radix on top. Your gauge description sounds about right for a mechanical gauge on a N/A vehicle. 25ish of vacuum at idle then rises up to 0 at WOT. With your SC, I'd expect to see some part throttle boost when you accellerate in the mid rpms. If the gauge was "broken" at 0, then you should hit 0 at part throttle accelleration. It still sounds like its not making any boost. Can you hear the ATI compressor screaming at you? If you are losing boost thats already gone through the MAF, then your truck would be running VERY rich because its expecting a lot more fuel. If you have 0 boost, and fueling is correct, then the SC compressor isn't working. Do you have any logging software? Random thought for testing: Can you put the stock intake tube and MAF back in their locations and run the truck N/A without removing a bunch of S/C parts? I think you could with minor intake parts changes. See how that feels. Leaving the S/C hooked up with the belt, put your hand over the intercooler outlet to feel the pressure while you have someone revv up the truck. Link to comment Share on other sites More sharing options...
j4nash Posted May 24, 2005 Author Report Share Posted May 24, 2005 The ATI compressor is not screaming by any means, I can hear it when i get in to it but it just sounds like it is really not working very hard. my exhaust does flow really well, the only thing I could do to make it better would be to take out the cats. Link to comment Share on other sites More sharing options...
j4nash Posted May 24, 2005 Author Report Share Posted May 24, 2005 When I sit there at idle the blow off valve is putting off a lot of air so I think the compressor is working fine. But I do know that when we were tuning the truck it was really rich, but that was after we had put in 44lb. injectors and a inline fuel pump. Link to comment Share on other sites More sharing options...
quickmedic1 Posted May 24, 2005 Report Share Posted May 24, 2005 When I sit there at idle the blow off valve is putting off a lot of air so I think the compressor is working fine. But I do know that when we were tuning the truck it was really rich, but that was after we had put in 44lb. injectors and a inline fuel pump. <{POST_SNAPBACK}> Make sure the blow off valve is working properly and not bleeding off pressure under boost. Once you are sure the guage is working that is. There is an arrow on the valve showing flow direction...at least on my p1sc for my TA. That valve can be installed backwards or sticking open. Also make sure you are not sucking a tube closed under boost starving you from air. Also make sure you have no belt slippage. I had this problem when Brian did my tuning. Good luck Link to comment Share on other sites More sharing options...
FuelSlut Posted May 25, 2005 Report Share Posted May 25, 2005 besides the lack of power you feel you should have, how is the vehicle running otherweise? any other symptoms... problems... etc. etc.??? bad MAF? bad MAP? as far as the boost gauge goes, i had the same sounding problem with mine till i found the right line to branch off of ( what part number/brand )exactly gauge do you have? Huddle up boys, we need to get this guys 500 to the pavement!!! Link to comment Share on other sites More sharing options...
j4nash Posted May 25, 2005 Author Report Share Posted May 25, 2005 i have the auto meter phantom gauges well i am going to go over everything again tomorrow night and if i still can't i will be putting a different pulley on Link to comment Share on other sites More sharing options...
Wizard Posted May 26, 2005 Report Share Posted May 26, 2005 I have the same gauges along with an ATI. I can tell you the mech gauge is off by aobut 2lbs. My gauge with a 3.60 pulley says as much as 12lbs. When it was on the dyno it read around 9. Why do some of you guys not recommend the ati blow off? Wiz Link to comment Share on other sites More sharing options...
j4nash Posted May 26, 2005 Author Report Share Posted May 26, 2005 Well tonight I checked all my fittings and they were tight and were not leaking any boost, but on the bright side I got my fuel gauge to work Now I just need to put a smaller pulley on and then maybe I can get some boost. Link to comment Share on other sites More sharing options...
BigTex Posted May 26, 2005 Report Share Posted May 26, 2005 Well tonight I checked all my fittings and they were tight and were not leaking any boost, ... You aren't leaking any boost? You said you have 0 PSI at WOT with a Procharger. Thats not right. Swapping pulleys isn't going to give you back your missing 8psi. Its a physical problem somewhere, either fittings, a leak somewhere, blow off valve, bad compressor, something.... No way it could be headers or camshaft, get over that. I doubt the pulley will cure it either. Just take it to someone who knows what they are doing and get it fixed. You'll save time, money, and get it running properly that much sooner. Link to comment Share on other sites More sharing options...
FuelSlut Posted May 26, 2005 Report Share Posted May 26, 2005 a smaller pulley isnt your answer... a smaller pulley should be an upgrade, not something additional to get you where you whould be starting from, thatd be the last thing id be thinking of after having spend that much already... hold off on th epulley dude, get this thing going right first Link to comment Share on other sites More sharing options...
j4nash Posted May 26, 2005 Author Report Share Posted May 26, 2005 i checked the fittings, and did not find a leak anywhere. as for the blow off valve, it was mounted on the pipe when i got it just like the it was when it did work for the last guy. I don't think the compressor is bad because to kit worked for the last guy when he took it off. i can't find a leak but i guess i can still glue the fittings today. Link to comment Share on other sites More sharing options...
smithl3 Posted May 26, 2005 Report Share Posted May 26, 2005 j4nash, I am going through some similar loss of boost issues myself. The only way I can honestly think to check for leaks is to pressurize the system. I am assuming you haven't done this as of yet. I too checked by hand all the connections and clamps and they all appear to be sealed and plenty tight. My solution to check the system is: I bought two 4” Rubber end caps for PVC plumbing, one of which I will put on the input to the charger, and the other I will put on the ABS plastic procharger piece that inputs to the throttle body. I also bought a 1” PVC end cap where I drilled and installed a Schrader valve in order to put pressure to the system. The little 1” piece with the Schrader valve you put in place of the bypass valve and this way you can put a static pressure to the system and actually listen for leaks. It should be completely air tight. I am trying it this weekend, if all goes well, I can send the stuff out to you to try. I also rigged up another Schrader valve set up to test my boost gauge which I also recommend you do. That too should be able to hold a static 30 lbs. And all you would need to check the system is a tire pressure gauge since it has the Schrader part build into it. I’ll let you guys know how this goes; this same idea will help you too isolate your problem. Good luck Link to comment Share on other sites More sharing options...
smithl3 Posted May 26, 2005 Report Share Posted May 26, 2005 I also forgot to mention, in light of this thread I went and checked my guage with my diablo scanner. Since the MAP sensor is only 1 bar I can only verify up to 15 psi, but at idle conditions I can compare the inches of mercury on the gauge to the psi from the map sensor. I would read 18.5-19 inches of mercury with the autometer guarge, and if I did my calculations right is that is 5.3-5.6 psi. Where my Map sensor would read 6.1 psi. So according to that my gauge reads low by at least .5 psi. I tried it again at 21 in. hg. and the MAP read 5.1 psi (21 in. hg. is 4.4 psi, so it again is over .5 psi off.) Not sure if any of this makes sense to you or if I did my conversions correctly. (I converted the in. Hg. to psi and then subtracted it from atmospheric pressure to get the reading in absolute presssure(MAP pressure)) Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted May 26, 2005 Report Share Posted May 26, 2005 I also forgot to mention, in light of this thread I went and checked my guage with my diablo scanner. Since the MAP sensor is only 1 bar I can only verify up to 15 psi, but at idle conditions I can compare the inches of mercury on the gauge to the psi from the map sensor. I would read 18.5-19 inches of mercury with the autometer guarge, and if I did my calculations right is that is 5.3-5.6 psi. Where my Map sensor would read 6.1 psi. So according to that my gauge reads low by at least .5 psi. I tried it again at 21 in. hg. and the MAP read 5.1 psi (21 in. hg. is 4.4 psi, so it again is over .5 psi off.) Not sure if any of this makes sense to you or if I did my conversions correctly. (I converted the in. Hg. to psi and then subtracted it from atmospheric pressure to get the reading in absolute presssure(MAP pressure)) <{POST_SNAPBACK}> You can only verify up to 7lbs of boost with a stock (or other 1 bar) MAP sensor. The truck will read one atmosphere (7.5psi) with 0 boost. Link to comment Share on other sites More sharing options...
smithl3 Posted May 27, 2005 Report Share Posted May 27, 2005 One "1" atmosphere is 14.7 psi unless I am taught wrong. And I know for a fact that my MAP sensor reads up to 15 psi at "0" boost on my autometer gauge. Am I missing something here?? No matter what I do with my truck my MAP sensor never reads more than 15 lbs. which should be atmospheric pressure, while my gauge reads higher than that (when it isn't leaking boost) I attribute this to that it is a 1 bar sensor and it doesn't have capacity past that. Turbo I respect your opinion here as you have been dealing with you truck for much longer than me, but what am I missing?? Link to comment Share on other sites More sharing options...
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