Thumper Posted September 25, 2004 Share Posted September 25, 2004 I am going to order one of these for my l28et and I was reading the instructions on the web page and it says do not use the original wastegate line as your boost source. It was said on the instructions page, http://www.dawesdevices.com/SDinstructions.html, part 3, line 2. I am going to install it the way they say but I am wondering why wouldn't you use the original? I think it would be much easier to install this way and I can not think of any negative side effects. Although I do not have the car infront of me to tell me where the vacuum tube is located in the intake tract so maybe I am missing something. TIA Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 25, 2004 Share Posted September 25, 2004 Your original WG source has a 'Y' fitting and two ports on the turbo. I blocked off the low pressure port and just ran the high pressure (outlet side of scroll) to the MBC. It worked great and didn't boost spike noticeably. Doug Quote Link to comment Share on other sites More sharing options...
Guest MaXbOOst Posted September 25, 2004 Share Posted September 25, 2004 goto home depot , $15 and you can have an IN-CAR MBC ............ mine works great ! ! just like this one : save you some $$$ Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 27, 2004 Share Posted September 27, 2004 When I originally installed the grainger boost controller on my turbo before installing my I/C, I used the stock signal line, using both feeds from the turbo housing Y'ed together just like stock, but with the Grainger in line. Spiking was very minimal with the grainger set to 10psi and the controller worked great. When I later installed my I/C the grainger started to behave kinda oddly when set up like this. Boost would initially rise to one point, say, 12psi, which is where I tried to set it initially. It would hit that boost at about 3200rpm, and then boost would slowly fall as revs climbed, and would be down from 12 to about 8psi by 6000rpm. I since have switched the signal line to the wastegate actuator to feed from the intake manifold, and don't have that problem anymore. Boost does spike noticeably more (partially an effect of the much longer hose I have to use to reach from the manifold to the WGA I think), I have it set to 14psi and it will spike to about 15-16 before settling, but will remain at 14psi all the way up to redline. I wouldn't try to do the in-car MBC... if only because given the length of hose required to run from WGA into the cabin and back to the WGA will most likely cause pretty severe spiking at it will take that much longer for the boost signal to loop all the way around like that and open the WG. Quote Link to comment Share on other sites More sharing options...
Thumper Posted September 27, 2004 Author Share Posted September 27, 2004 Well thanks for the info. I will be ordering two of them tom. One for me and one for my friends gti 1.8t. I will not be using the stock vacuum tube so I think i'm going to drill a hole and put a small nipple right after the turbo so that I can the least amount of spiking. Thanks for help P.S. 13's here I come Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted September 27, 2004 Share Posted September 27, 2004 To minimize boost spiking in grainger type valves, use the shortsest amount of tubing between the Graniger Valve and the Wastegate actuator. Also use the longest, softest spring you can get away with inside the Grainger Valve. A long, soft spring won't change its preload when the ball compresses it as much as a short spring--less spike. I have almost ZERO spike at 13 psi with the dual, concentric, pen springs I am using. I did have to use a short piece of shiskebob stick inside the springs to keep them from bending sideways and catching on the inside of the valve body. Rigged, but it works very well. And wastegate stays slammed shut until 13psi. It can't get better than that. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 27, 2004 Share Posted September 27, 2004 LOL Cyg... as a hack you are awesome with a lot of these ideas of yours. A long soft spring with a piece of shishkebob stick inside eh?? I like it! Okay so where EXACTLY did you get your springs from, and why are you using two instead of one? By any chance can you take a pic or two? I do get more spike with my grainger than I'd like, about 2psi worth at 13-14psi... I hate because the car surges pretty noticeably... you can feel the boost spike and fall. It wasn't a problem at 10psi before the I/C. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.