Manual Boost Controller SPIKES

[blhlfam]

I've been using a grainger valve for a couple of years with the normal boost spikes and tried everything to elimnate them suggested in all of the various web pages. So I broke down and purchased the $44.00 Hybrid boost controller from Dawes devies that supposedly has "no spikes" well it doesn't work any better then my $15.00 grainger valve. I've followed all of the insturctions, hoses are as short as possible coming off the turbo going right to the wastegate can. Hole isn't plugged. I just with that the factory made a HP computer for the Turbo III cars. My turbo II cars with MP computers work perfect no spikes very consistent. I tried an aftermarket TIII custom calibration and that was a joke the car made less power with it then it did stock. So I turn to the bleed and it is so inconsitent it drives me nuts.

Any ideas not found on web sites, i get about 2lb spikes, and not very happy about my $44 dawes controller, which is exactly what I got with my $15.00 grainger valve. He doesn't even have any way to contact him on his web pages. I wonder how he can claim a 99% satisfaction rate with no way to give feedback or questions on the web page. His Air fuel ratio gauges are great though.

Brett

[Xplizit]

try replacing all the vaccume lines and making or buying a better vaccum distributor block. someone on here sells custom ones for like $15.. ask around, and ill try to find the guys name/number...

[D-Cal]

Port the wastegate hole.

[jacksonrt]

I had the same problem with my 91 R/T. I went from a Turbo XS to a grainger only to find out that when adjusting waste gate rod I actually had gotten it to tight. Seems to only be a small area of adjustment that mine didn't get a 4-5 psi spike.

[GLHNSLHT2]

Quote:

Originally Posted by D-Cal Port the wastegate hole.

agreed. hole can't vent enough fast enough.

[blhlfam]

So remove the waste gate actuator and drill the vacuum nipple hole a little larger? Is that correct?

Brett

[turbovanman]

I guess you have tried shimming the can or loosening it up?

What type of exhaust are you running?

Anyhow, you don't port the can nipple, you port the actual wastegate passage on the turbo. On yours, if it is a TIII turbo, you will have to remove it as the passage is built into the turbo housing and not removable.

[blhlfam]

Ok understand porting the wastegate hole makes more sense, but not worth it for me. I run at 2.5" exhaust with Cat only and with everything else hooked up as stock I've run 14.17 at 98 mph at 4,500 feet pretty consistently, I was just trying to bust into the 13's. And stay under the overboost cutout. I tried a zener diode and it screwed up my ignition timing which cost me a valve when it blew the edge of it off from detonation.

I just am frustrated that Dawes advertises "no boost spikes" 99% satisfaction, and I'm curious how he can know whos satisfied or not when he offers no way to contact him on his web site. I guess if you don't listen to your customers you can assume they are all satisfied. I just don't think you can stay in business very long. I repair a lot of peoples Shelbys in Salt Lake and a lot ask my opinion on mods. So mine will be save the $44.00 on a hybrid boost controller and stay with the basic grainger valve and expect a 2-3 lb boost spike Hybrid or not. I Just wish someone made a dependable computer calibration for the TIII cars.

I appreciate all of your suggestions and help. This forum is great. I'm surprised the SDML still even exists, the information there is useless most of the time. Thanks also for all of those who created the Turbo Dodge mailing list. Its helped me solve a few mystries on my cars recently.

Brett

[turbovanman]

Quote:

Originally Posted by blhlfam I tried a zener diode and it screwed up my ignition timing which cost me a valve when it blew the edge of it off from detonation. I Just wish someone made a dependable computer calibration for the TIII cars. I

Ok, we all use Zeners and cut-out raisers with no issues. It doesn't affect your igntion timing. Of course, you have to make sure you have the correct air/fuel and egt's as the computer only has tables for before cut-out. Take it above that and you'll go lean, thats probably why you melted a valve. What guages do you have?

As for cals, www.******************** There custom made to each application.

[blhlfam]

Quote:

Originally Posted by turbovanman Ok, we all use Zeners and cut-out raisers with no issues. It doesn't affect your igntion timing. Of course, you have to make sure you have the correct air/fuel and egt's as the computer only has tables for before cut-out. Take it above that and you'll go lean, thats probably why you melted a valve. What guages do you have? As for cals, www.******************** There custom made to each application.

Actually on the Turbo III it does effect timing, since the zener doesn't allow the computer to see your actual boost levels it adjust the timing for what the zener allows it to see. As I'm sure you know the TIII has no distributor and is completely computer contolled instead of just partially. The turbo II and I, it probably doesn't. But I can tell you for a fact that if your running boost levels above what the Zener allows the computer to see it doesn't know how much to retard the timing. I fought this issue for 6 months until someone on the list told me this. As soon as I removed the zenner i was able to run 13lbs of boost with out detonation, with the zenner at same levels i had major amounts of detonation with very rich signal on the AF ratio.

I was told that you can buy an adjustable zener and allows the computer to see a little higher levels then the non adjustable allows it to see with out getting overboost shutdown but most of the ones I've seen are calibrated for the Turbo I & II ranges of voltage it allows through.

[turbovanman]

Quote:

Originally Posted by blhlfam Actually on the Turbo III it does effect timing, since the zener doesn't allow the computer to see your actual boost levels it adjust the timing for what the zener allows it to see. As I'm sure you know the TIII has no distributor and is completely computer contolled instead of just partially. The turbo II and I, it probably doesn't. But I can tell you for a fact that if your running boost levels above what the Zener allows the computer to see it doesn't know how much to retard the timing. I fought this issue for 6 months until someone on the list told me this. As soon as I removed the zenner i was able to run 13lbs of boost with out detonation, with the zenner at same levels i had major amounts of detonation with very rich signal on the AF ratio. I was told that you can buy an adjustable zener and allows the computer to see a little higher levels then the non adjustable allows it to see with out getting overboost shutdown but most of the ones I've seen are calibrated for the Turbo I & II ranges of voltage it allows through.

Ahhhhhh, thank you for that little tidbit. I didn't know that. One more piece of info to store in my little brain,