Jersey Posted September 10, 2003 Share Posted September 10, 2003 Hey all. Couple of questions. 1 - Why are there 2 boost reference lines coming off of the T3, T'd together then running to the wastegate? 2- Is there any difference between the 2 ports off of the T3? 3 - What size are these lines - 5/16"? 4 - When hooking up one of those Graniger/Dawes MBC's, do you leave both lines T'd together and put the MBC after the T or is it better to cap one of the lines off and just use one of them to your MBC? Hoping to get to the track friday night. Last night - 4am, finished 3" exhaust with straight-through muffler and put on 235/60's and took it out for a run. NICE. A little loud for my taste but good for the track. As i was watching my boost gauge, which was set to 10psi before i took it off the road for the exhaust, it was hitting near 18 psi! I noticed it because it just started to ping and i know she never pinged @ 10psi. Checked both lines that are T'd together and running to the WGA, seem to be fine. Pulled on the threaded WGA, opened and closed the WG smoothly. So i'm thinking it must be a leak in one of the T3 reference lines or the WGA diaphram. Tell ya what...18psi is fun as heck! haha. Anyway, that's my battle for tonight. Also doing the MSD install which seems simple enough. Thanks in advance for any info. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted September 10, 2003 Share Posted September 10, 2003 1. to get more accurate signal 2. One would give alittle higer boost level earlier since it's closer to compressor wheel 3. Beats me, I just use some fuel line on mine. Tighter is better IMO 4. I hooked my MBC after the T as you discribed. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 Yep leave both lines on there and put the MBC after the T. The hoses are 5/16". I had a similiar problem as you two days ago after getting the head back on, went for a drive and one of hoses came off the turbo body, boost hit 15psi and I heard a couple pings before letting off. I agree... it WAS fun I find it odd that this turbo just refuses to produce more than 15psi, the mechanic told me that the hose had also popped off on him (crappy old nissan clamps) and it had also risen to 15psi but then leveled out. Wonder why it tops out there? Anywho, I also just installed my MSD 6A yesterday... it's very easy, and here's a tip, you do NOT need the tach adapter to run it, or at least, I did not. I decided to just try w/o the tach adapter this time simply becuase I was being lazy and didn't want to find a place to mount it, and sure enough if fired right up. Installing it actually made a huge difference this time, in how the car runs. It really helped with the stumbling and misfiring problem I was having, and also helps the car start easier. Quote Link to comment Share on other sites More sharing options...
Jersey Posted September 11, 2003 Author Share Posted September 11, 2003 Thanks Yo and 525. Didn't hook up the Graniger device last night. Couldn't find a brass 90deg elbow for the one side of it (rather not use plastic) but i did clean up 3" exhaust, new thermastat and put the MSD in. I unscrewed the WGA a little before i went out and sure enough, it was the 2 1/2" mandral bent exhaust that was giving A LOT more back pressure than i thought. Instead of boosting to 18psi with the new 3", it went down to a safe 13psi. Never had a tach adapter with my MSD 525. When i had it hooked with my N/A L28E, I used the 280 tach, changed the face to the 240 for the redline an jumped out the internal resistor and then could use the tach output port on the MSD. Did the same last night and it works great. I didn't see any major difference with the MSD but it may hold the spark a little stronger at higher boost at the strip tomorrow night. We'll see. Thanks again guys. Quote Link to comment Share on other sites More sharing options...
BayAreaZT Posted September 11, 2003 Share Posted September 11, 2003 Jersey - are you saying you went from 10psi on the 2 1/2" exhaust to 18psi with the 3" exhaust without changing the boost setting? Thats a big jump. I guess I need to hurry up and get my 3" exhaust done. Quote Link to comment Share on other sites More sharing options...
Jersey Posted September 11, 2003 Author Share Posted September 11, 2003 Bay, i swear. I had my wastegate adjusted to 10psi and was running it like that for a week or so before i took it off the road for the exhaust. After i put the 3" mandral bent to one of those 4" bullet straight through mufflers, i took it back out and she was boosting up to 18psi. I did nothing else that would make it boost like this. I still don't believe that the 2 1/2" mandral going through a super turbo muff was giving it that much back pressure but, when i cranked my WGA out a little last night, it went down from 18psi to around 13psi so nothing else is wrong with the system. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 11, 2003 Share Posted September 11, 2003 Jersey you can order the brass elbow from mcmaster-carr. http://www.mcmaster.com part #44555k142 and dont forget to drill a .020" hole in it or it will hold the wastegate open between shifts I know this is just grasping straws, but I wonder if your huge leap in boost from one exhaust system to the other has anything to do with the method you were using to increase boost. I know when I was driving around with only the downpipe on mine, and had set the boost to 9-10psi, then went and had a crappy restrictive 2.5" crush bent system installed with the glasspack, my boost did not change at all. *shrug* different things for different cars I guess? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted September 11, 2003 Share Posted September 11, 2003 My boost also did not change from 10psi with stock downpipe or 2.5" mandrel bent downpipe, FWIW Quote Link to comment Share on other sites More sharing options...
Jersey Posted September 11, 2003 Author Share Posted September 11, 2003 The method i used before the exhaust and after is the same - threaded WGA. I didn't put the grainger valve in because i didn't get the brass 90degree elbow. I was going to order it from mcmaster but i figured it wouldn't be a problen getting it from the local grainger shop over here. They had nothing. Go figure. I have no idea why it started boosting so high immediatly after i put the exhaust on. Maybe just a coincidence but, fine with me Quote Link to comment Share on other sites More sharing options...
Drax240z Posted September 12, 2003 Share Posted September 12, 2003 Hey Jersey, you got the stock 280z tach to work with the MSD box? I'm having issues with mine. Can you be more specific about what you did and how you hooked it up? I've borrowed an autometer tach for the time being, but can't get the 280z tachs I have working... AFAIK, the red/black wire out of the back of the 280z tach is the signal, the black ground, and the green is power. I've been hooking the red/black signal wire to the blue wire on my MSD box (which works fine for the autometer, but not the 280z). The tach output port on the box requires a plug of some sort in order to use it I assume? Any insight? Quote Link to comment Share on other sites More sharing options...
Jersey Posted September 13, 2003 Author Share Posted September 13, 2003 Drax. You have to open up the 280 tach and jump out the BIG inline resistor. There are 2 inline, just jump out the big one. Then all you need to do is hook a wire that comes from the back of the 280 tach's sensor lug and run it to the MSD tach signal port. It's just a male spade on the MSD side so all you need is a female spade and plug it right in. The value out of the MSD tach port is too low to run the 280 tach so that's why you jump out the internal resistor. I think i still have notes about jumping out the internal resistor if i wasn't clear enough here. Just got back from the track and my darn head is filled with fuel!!! Let me know if you need more info. And BTW, it is dead accurate using the MSD tach port. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted September 15, 2003 Share Posted September 15, 2003 Thanks a lot bud, I'm going to give that a try really soon. Quote Link to comment Share on other sites More sharing options...
Jersey Posted September 15, 2003 Author Share Posted September 15, 2003 no sweat. Quote Link to comment Share on other sites More sharing options...
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