Cody 82 ZXT Posted June 17, 2003 Share Posted June 17, 2003 Ever since I have upgraded my fuel injection system and installed a 3" manderal bent DP I'm having a proublem controlling boost. It only does it when I'm first getting into boost. Running 15psi it will spike to 16 or 17 then back down to 15. Ocaasionally it will creep up and stay there. I've tried to adjust the settings on my Profec B but, it doesn't seem to help. Any ideas of what is causing this other than more power and freer flow. Do I need to port the wastegate hole? My turbo is a hybrid with a t04B unknown compressor wheel and stage two or three exhaust wheel. Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 17, 2003 Share Posted June 17, 2003 im thinking you have to port the wastegate hole, profec b is supposed to be really good at keeping the boost in check, but it cant if its limited to wastegate hole like it sounds like.. didnt know you ran profec b, im actually trying to pick one of those up it would be my first ricer gadget box. do you have the one that learns the boost curve? im trying to pick one up from a friend soon, please let me know how you like it, or dont like. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 17, 2003 Share Posted June 17, 2003 try tighten down the WB actualator rod some. That seems to help in my car. Quote Link to comment Share on other sites More sharing options...
speeder Posted June 17, 2003 Share Posted June 17, 2003 Your problem almost certainly is inadequate wastegate flow. I experienced severe boost creep with a turbo very similar to yours - the wastegate port on my internal was really tiny - about 1/2". I think if you port the wastegate and possibly get a larger swing valve your problem will be solved. Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 17, 2003 Share Posted June 17, 2003 ive also heard of people boring the crap out of that wastegate hole and welding a washer the right size on the swing valve. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted June 17, 2003 Author Share Posted June 17, 2003 I thought that you guys would say I needed to port the wastegate hole. While I'm at it the housing could be ported as well. I almost did before I put everything together but, ran out of time. Looks like I should have made the time. Now, I'll be able to port the outlet of the turbine as well. Anyone have a recomemdation for how big not to go? MY DP has a 2 1/4 hole for the first 1/2 or so. Should I cut this off and make it 2 1/2? Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted June 17, 2003 Share Posted June 17, 2003 I use a upgraded larger wastegate door to allow more porting on the wastegate vent, it works. But unless you are boosting 18psi+ I don't think you should have a problem make sure the B is connected correctly maybe boost it without the controller. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted June 18, 2003 Share Posted June 18, 2003 Do not mess with the turbine housing and DP. The problem is the wastegate hole as previously stated. DO NOT, repeat, DO NOT weld a washer on the existing puck. Find out what larger pucks are available and that will help determine how big the hole can be opened up. It is a PITA, but if you get a bigger puck, I would install it before opening the hole to see the signature that the hole makes on the puck and then take it apart again and open the hole accordingly. Sometimes the puck is not centered perfectly over the hole and you do not want to make a bigger hole to discover it is not completely covered by the puck. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted June 18, 2003 Author Share Posted June 18, 2003 Thanks Scottie, you've got some good points about the wastegate hole not being centered perfectly. I'm not real sure about this one but, I remember some of the turbos that I've had in the past the puck was very off center. Honestly I really dread taking the turbo off and doing all this since right now my backup car is down. That makes major surgery on the Z alittle more difficult to do all in one day or afternoon. I'm going to look at the hoses for the Profec and make sure they are routed in as straight of path as possible. After that I'll have to get in touch with Alex for a larger puck. By the way how do you reattach a puck anyway?Is it welded on? I don't remember. Len, I really like the Profec B it's the simpler model of the line. I had a Profec A but, it kinda went crazy and started to do weird things. Also if you make any changes to the system you have to go out and let the Profec relearn your setup. The learning process is simple but, not the most practicle thing to do any place other than a dyno or race track. If your like me you change this relativley often. I did like the Profec A while it was working correclty. It has several features that are nice like programable over boost protection. Ofcourse the only time you really need this is if the unit is acting crazy. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 18, 2003 Share Posted June 18, 2003 Cody what are you using for an actuator? Is it the stock nissan one? If so I think you need to change to a dual port one. I never could get the stock actuator to work right on my car, with a stock turbo, so I doubt seriously it will work with a hybrid. Also as Yo2001 said, threading the rod and making the thing adjustable helps. I have never had to modify the hole in my turbine housing on my old turbo or this one I have now, and I never had creep problems, although I will say if my car was going to spike, it was going to be in second. I never had spike issues in any other gear. Going to the MBC on the bottom port has all but cured my issue's. Perhaps the Profec could do the same. I also agree with scottie about welding or porting. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted June 18, 2003 Share Posted June 18, 2003 To help boost creep, I had my internal wastegate hole bored out as far as functionally possible. I then ordered up a custom stainless steel lawnmower valve that happened to have a similar stem diameter and a larger valve diameter. This valve was used to replace the original flapper valve. I cut the stem to the proper length then had it welded up so that the pivot lash would seal the opening yet not catch on the edge of the hole. It works better than stock, but I still wish I had a nice Tial external wastegate. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted June 18, 2003 Share Posted June 18, 2003 What I sell is a complete wastgate door assembly from Turbonetics but if you have a stock Datsun exhaust housing its not going to bolt up. I don't overboost on my car with a small swing valve and it boost 18psi on a 60-1. I think you need to look long and hard at your boost controoler of maybe your fuel curve is affecting the power curve. Let us know. Alex C Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 19, 2003 Share Posted June 19, 2003 yeah that stuff is cool, im getting a profec b or the apexi with the tv screen i have to have at least one riceboy gadget. and i have to have scramble boost, no if ands or buts and no maybes. if i get the tv screen apexi, im putting it where the speedo used to be, sucker hasnt worked in two years. Quote Link to comment Share on other sites More sharing options...
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