Some quick questions......

[granitestategn]

My car has the stock wastegate solenoid set-up. I'd like to keep it that way. I like the chip to be able to drop a pound or two in third. Stock adjustable wastegate actuator, too. I put a THDP on my car a few weeks ago. I'm having some issues at the track. I can't seem to control my boost. I'm not sure it's related only to the downpipe install. When I put it on I enlarged the turbo exhaust housing hole to 1" diameter and ported it to clean up the sharp edge. Now when I'm at the track I'm having a difficult time getting the boost level up in the low gears but it creeps in the higher gears. I couldn't get more than 15 PSI in the low gears but it was at 17 or 18 in third. It seems like I've got the actuator pretty short. I'm also shorting the TCC wire on the starting line so it locks when I hit second gear. Is locking the TCC this way aggravating my boost control problem? The car is getting KR in the middle of the run but it decays on the top end. My KR is about 4 deg at .780 mV. My peak EGT's were about 1550 deg F. When I shortened the rod, my EGT's rose slightly (a couple degrees is all) and the KR didn't get any worse. The boost didn't seem to change much. My car ran a 12.98 @ 103 a couple weeks ago but Friday night I had a string of 13.1's. Still had 103's all night. Couldn't 60' better than a 2.0 or I should have been in the high 12's again. I'm not looking for above 17 or 18 pounds boost with this chip. Do I need to lock the TCC later? Anybody else see this problem before? TIA!

 

[Ttype6]

Re:Questions

As we shorten the actuator more and more to make more boost,the boost pressure acting on the actuator,is less able to move the actuator ,against the increased tension,to controll boost. This is why boost creeps up as R.P.M. increases. The way to solve this problem,is to leave the actuator as long as possible, and controll the pressure acting on the actuator in a different way. If we better manage the pressure acting on the actuator,and we do this with less spring tension,the actuator can move farther and faster,to better controll boost. This will better con troll boost creep in the higher R.P.M. range,and better controll boost spike during a gear change. The best,and least expensive way to accomplish this,is with a very specific type of universal manual boost controller that is available on eBay from a company called Lower_Shores _Performance. Go to eBayand type the words Seller List where it says (what are you looking for). then click on the word (Find It). then click on the words (find members). Then type in the words Lower_Shores_Performance,just as I have written it here. Now click on the words (Items for slale). When you get here,make a bid of $29.99 on the controller,closest to the top,that has'nt been bid on. Pay no attention to the listed applicatin,as these are universal and are all the same. The reason I say to bid on the one closest to the top that has'nt been bid on yet,is because each of these controllers is an auction in and of itself. The controllers closest to the top,have the least amount of time left on the bidding,so if you win it,you'll receive it sooner. Do'nt bid on one that has already been bid on,because you'll just be stopping that guy from getting one for $29.99. If you do'nt care obout the price,and do'nt have the patients,click on one that says buy it now for $34.99.

 

[Ttype6]

Re: Questions

P.S. When you click on one of these controllers to make your bid,make shure you scroll down the page to read the sellers explaination of how it works. You'll be able to read this without making a commitment to buy.

 

[granitestategn]

Thanks

Ttype6

Thanks for the reply. I would prefer to stay with the wastegate solenoid method. I guess to rephrase my original question: Can locking the TCC too early limit my ability to build enough boost in 2nd gear? If so, would this condition be aggravated by having a larger wastegate hole in the exhaust housing of my turbo?

 

[Ttype6]

Re: Questions

Locking the torque converter as you do (during the 1-2 gear change) probably causes a boost spike,and certainly makes the motor bog. I do,however thin this puts less of a strain on the lockup mechanism. A lower E.T. would be recognised if you lock half way through 2nd gear. I do however think this puts more of a strain on the lockup mechanism. The best way to lock,is with a multy disc lockup converter, like the one Presision Industries sells. Again, the controller I described will better control boost spike during a gear change,as well as boost creep in high gear.

 

[Ttype6]

Re: Questions

Locking the cluch does'nt lessen your ability to build boost. It does quite the opposite. This is why your experiencing so much creep. You'll never be able to controll it effectively with the stock wastegate solenoid and a tight actuator. The actuator wont be able to react quickly to a sudden need to bypass exhaust gasses around the turbine,such as during a gear change. It,also wont be able to move the wastgate far enough to controll boost creep in high gear. Go to eBay,as I described in my earlier reply,and read the dicription. It costs nothing to look.

 

[Ttype6]

Re: Some Questions

I was thinking about when I put my T.H.D.P.on my car,and I remembered something that might pertain to you. Since the pipe was an aftermarket piece,I just could'nt trust that the wasegate puck would be exactly in the center of the hole in the turbine housing,soI bolted the pipe on without first enlarging the hole. I drove the car for a about a week,then removed the turbo to see if the puck left a distinct mark showing exactly where it rested against the turbine hosing. It did. I was glad I did this,because the mark left by the puck clearly showed that it was off center of the hole.The mark showed me exactly how and where to grind to enlarge the hole. Did you do it this way,or did you enlarge the hole first. If your puck is'nt completely covering the hole you would experience low boost,becaue too much exhaust would be allowed to bypass the turbine. Maybe you would have also notice that the boost did'nt come on as quickly as it used to. Naturally you would shorten the wastegate actuator to increase boost,and you might have noticed that shortening it the amount that you did,did'nt produce the amount of boost increase that an equal amount of shortening did in the past(before you installed the pipe). So you shorten the actuator arm more and more to try to increase boost. I think this could explain the boost creep in high gear,because (as I explained in an earlier reply) the more you shorten the rod the less distance the wastegate can travel. This leads to boost creep. Does this senario sound anything like what happened to you? Let me know.

 

[granitestategn]

Nope, I checked first.

Before I enlarged the hole to 1" I took the exhaust housing off the turbo, mated it to the downpipe, checked to see how much wiggle room it had in the bolt/stud holes (not much at all). Then I coated the wastegate puck with a thin coat of neversieze and closed it by hand. I took the downpipe off and there was a very distinct outline of the puck on the exhaust housing. Set it up in the Bridgeport mill with a 1" end mill and clamped it down, then centered the end mill on the outline and bored it. When I was done I rechecked it and it was close to perfect. I then used a die grinder and smoothed the inside radius of the hole on the to get rid of the sharp edges. I'm gonna try backing off the rod some and start over. I checked the ebay auction you mentioned. It looks like a brass tee drilled and tapped through the side. It used a backpressure relief and a needle valve bleeder. If I got that route I will probably just get a couple of regulators (a backpressure regulator and a low pressure relieving regulator) and hook them up in series. It should be a little more accurate and repeatable. About double the cost of that one, but still relatively inexpensive. McMaster-Carr sells both.

 

[Ttype6]

Re:Questions

It sounds like you did all the right things during your instalation. If you disconnect the hose that hooks to the wastegate solenoid and leave it unplugged,and drive the car,you should be able to make more boost than you need. DO NOT USE FULL THROTTLE. Gently apply throttle while watching the boost guage closely. The solenoid is used to allow pressure,trying to push on the actuator, to bleed off into the atmosphere. This leaves less pressure available to move the actuator,so it moves a lesser distance which allows boost to rise above what the actuator is set at. Leaving the hose unplugged lets all available pressure bleed of,so the actuator does'nt move at all. this will create an over boost condition,so be careful. If doing this creates all the boost you could ever ask for,then your turbo and actuator are good. the problem is the system that manages the pressure trying to act on the actuator. If you leave the hose disconnected and plug it with a screw or golf tee,you should experience less boost than you did the last time you were at the track,because all available pressure will be allowed to move the actuator. If you find that this proceadure produces an equal amount of boost as the last track visit,it is another reason to suspect the system that controlls the pressure acting on the actuator.(computer,wiring ,and solenoid) The reason I prefer to fix this problem with the boost controller I showed you,is because it does a better job of managing the pressure. see what the results are of doing these things.

 

[granitestategn]

Road test

Next time I did out the car I'll take it for a road test and try the suggestions you gave me. Thanks for the help.