Need vnt advice

[ironbird720]

Recently bought a 90 vnt daytona shelby and i was wondering what normal boost is.My turbo is very loud and psi climbs quick.Getting about 5psi max.Is that normal or is my turbo pooched?Feels like better accel at half throttle than full.Doesn't feel like 174hp.Motor is stock except k&n and MSD but exhaust is on the way.Have heard that turbo vanes may be stuck in aggresive position or wastegate problems.Then again I've heard vnt's don't have wastegates.Can anyone give me some concrete advice?Any info is much appreciated.

My VNT had same issue, when I bought it. In my case I found the timing belt 1 tooth off. After fixing that, car picked up a ton

[DirectConnection]

Many things could be causing this. Timing belt off like someome mentioned is a good thing to look into. This seems to happen everytime a mechanic who doesn't know the 2.2's as well as he thinks he does.

If the turbo crapped the bed, you should see blue smoke out the tailpipe. Do you?

I had a broken vacuum line to my actuator for the vanes (no wastegate) crack and I got all the boost I wanted, but 25psi and climbing is not good. I guess the opposite could happen with a bad vacuum line or one not hooked up correctly. Your vanes would need to be full open. Possibly stuck, like you said. In the engine off position, the rod on the housing that controls the vane actuation should be up against the stops. That is the vane's fully closed position. I believe it is spring actuated in the actuator itself. You should be able to push *real* hard on the rod/lever and move it down (full open) as the spring with want to pull it back up. Do this several times and see if it frees anything up. (I've never seen this happen, but worth a try)

Do you have any codes?

[ironbird720]

Thanks for the info.I recently found out what the problem was the day I put my exhaust on.I was driving it hard that day and when I slammed 3rd a big puff of smoke blew out the exhaust and continued after that.Turbo is pooched.The shaft had 3 to 4 mm of play.Needless to say I ordered a new vnt and had my head rebuilt with a new cam and lifters.Just got it back together today and there is a very noticible difference in power.Hard to get traction in 2nd now.Getting tons of boost now.Boost is going off the gage now,way up past 15.I want to get a new aftermarket gage now to see how much boost i'm really getting.Why would the boost be so high with a new turbo?I was told stock psi is 12....? I've only put 2.5 straight back into a ravin performance exhaust and msd
ignition.How much adjustment can you get with a boost controller?

p.s. no codes

[crazyace]

It sounds a lot like you have at least one vacuum line routed improperly or leaking out to atmosphere. Do not let that thing keep boosting out of control like that unless you feel like buying another turbo soon. If it is flying off the gauge that way it could be even hitting the low to mid 20's psi wise. Do you have an A/F gauge even? An A/F gauge or EGT gauge is always a suggested if you are running over stock boost. If not you could even be running it lean. If you are not going much above 15psi it may even be getting caused by the more freeflowing exhaust, a well flowing exhaust can make it very difficult for the computer to control the boost.

[ironbird720]

I've heard about freeflowing exhausts to cause overboosting but after I put the exhaust on with the old turbo there was no change inboost levels.Since the new turbo I have tons of boost and I don't want to blow it up.I think I have a vac line or 2 routed wrong.The overkill boost is nice though,can hardly get traction in 2nd.Don't know much about A/F and EGT gages.I would like to be able to adjust my boost when needed.Is that possible??

[crazyace]

With out either of those gauges I and most others on here would never even consider suggesting you go over stock boost. The turbo is expensive but an engine is a lot more expensive. If you want to risk it that is up to you, but your taking the engines life for granted if you do.

[87shelbyVNT]

i need some advice also, i have a t2 2.5 shelby daytona. i was looking at super 60 kits (computer,turbo,fuel pump, and injectors) but i think it might end up to be more money than i really want to spend right now. what do u think about just putting a VNT turbo on my 2.5, will it run as good as my fathers VNT lebaron? or do u think i should just leave the t2 on it? THANKS, Kevin

[ironbird720]

ok,bought manual boost controller and I'm trying to hook it up.Couldn't get it to work.I'm not sure which nipple on the wastegate it should go to.Big one or small one?I closed the valve all the way and I tried both lines and still got overboost.What am I doing wrong??



thanks,turbo retard

[crazyace]

Ironbird, it sounds a lot like you have a solenoid not opening as it should. Look under your hood at the little line going to the actuator. Trace that line back to the soenoid on the passenger side. Take the two vacuum lines off of that solenoid and put your MBC in place of it. Set the MBC very low to start off with. If you can now control it, replace that solenoid. They are known to fail intermittently and are not very expensive. The small line is the one that controls peak boost.

[ironbird720]

crazy,I traced the small line coming from the canister to the solenoid.It happens to be the top nipple on the canister.I unpluged it and hooked it to my MBC.The other vac line on the solenoid goes to the bottom nipple on the turbo housing.I pluged it in to the other side of the MBC and still had no effect.I even tried to turn the MBC around but it made no diff.I think I'm going to buy a new map sensor today as well.Any other suggestions??The bottom nipple or large one on the canister has lots of vacuum going to a seperate solenoid but the small line has nothing.What else should I try??

[crazyace]

It is starting to sound as though you either have a miss adjusted or junk actuator on there. If you have access to an air compressor you may want to try applying light air pressure to that top nipple on the actuator and make sure you see it move the arm. Also check to make sure you can physically move that arm yourself in both directions. Something is definitely a miss there, that much is for certain. Why are you replacing the MAP? If you do, be certain is with a Mopar one. I can not stress this enough to people. Even Napa's electronic parts have went way down hill in the last few years.

[ironbird720]

S#!t,I wish I read that earlier crazy because I went and bought one from crapy tire,although it did make a diff.She's idling pretty normal now but still smokes alittle when you give it gas arter a light.And she is not overboosting either.I still have the MBC hooked up like you said but I don't think it is working because it's turned almost all the way closed and I'm still getting just under 15 psi boost in gears 1-4 and 12-13 psi in 5.I also had to put a clamp on the hose going to the bottom nipple on the turbo housing because it kept blowing off.I will keep mucking with the MBC

[ironbird720]

I was coming home today and I blew the pvc hose and it was hissing very loud.So I replaced the hose and the pvc valve plus the ripe on the hose going to the bottom nipple on the turbo housing.Overboost seemed under control until this happened.After I replaced everything I was overboosting again. one prob after another any ideas??

[crazyace]

Like I said before, make sure that the actuator can move both ways. It sounds like it got improperly adjusted before installation on the engine.