greddy wastegate woes
#22
I have a brand new 8psi wastegate can. This is the same one that Joe used on his greddy kit.
http://www.flyinmiata.com/index.php?...umber=02-70576
$35 + shipping.
http://www.flyinmiata.com/index.php?...umber=02-70576
$35 + shipping.
#23
I have a brand new 8psi wastegate can. This is the same one that Joe used on his greddy kit.
http://www.flyinmiata.com/index.php?...umber=02-70576
$35 + shipping.
http://www.flyinmiata.com/index.php?...umber=02-70576
$35 + shipping.
#24
I won't be able to give you a shipping quote until tuesday, tomorrow is a holiday here.
Jay
#25
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,339
Total Cats: 6,793
Took me a while to find the pictures. My bracket actually isn't as cool as Koto's, just a piece of 16ga sheet steel. Also, mine is a different can; rather than the two studs, it has a welded-on flange. Otherwise identical, but I got it new on a DOTD quite cheaply.
The bracket on the WG can had to be trimmed significantly. You can see below how the position of the nipple relative to the bracket is wildly different. Thus, the new one is rotated appx 90° CCW (viewed from front) relative to the old, necessitating the trimming of its welded-on bracket.
I also cut the rod and eliminated the latter of the two bends, causing the end of the rod to be offset relative to centerline. The rod was almost exactly the correct diameter for threading to 1/4-20, so I just ran a die down the ends after cutting, and used .25" threaded hex couplers to re-assemble. (when threading, support the rod in the vise, not the can)
The two together, before modding the new one:
The new can in place, modification of rod is obvious:
Slightly better shot of bracket (this turned out to be hard to get a good picture of):
The holes in the compressor that the bracket now is fastened to were filled with setscrews originally. Just pulled 'em out and replaced with bolts.
No helper springs, and with the MBC she holds a rock-solid 13PSI to redline.
The bracket on the WG can had to be trimmed significantly. You can see below how the position of the nipple relative to the bracket is wildly different. Thus, the new one is rotated appx 90° CCW (viewed from front) relative to the old, necessitating the trimming of its welded-on bracket.
I also cut the rod and eliminated the latter of the two bends, causing the end of the rod to be offset relative to centerline. The rod was almost exactly the correct diameter for threading to 1/4-20, so I just ran a die down the ends after cutting, and used .25" threaded hex couplers to re-assemble. (when threading, support the rod in the vise, not the can)
The two together, before modding the new one:
The new can in place, modification of rod is obvious:
Slightly better shot of bracket (this turned out to be hard to get a good picture of):
The holes in the compressor that the bracket now is fastened to were filled with setscrews originally. Just pulled 'em out and replaced with bolts.
No helper springs, and with the MBC she holds a rock-solid 13PSI to redline.
#27
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,339
Total Cats: 6,793
One small epitaph- I did this because I too was having problems with boost dropping off with RPM. If it was at 13PSI @ 3.5k, it would gradually drop and by redline be at maybe 10PSI. This can did not (by itself, anyway) solve the problem.
AbeFM gave me the answer, which in retrospect seems blindingly obvious but at the time hadn't occurred to me. I was still taking the WG boost signal from the stock location on the compressor- before the intercooler.
The intercooler is a restriction. Thus, when air is flowing through it there is a pressure drop between the inlet and the outlet. The amount of this drop is not a constant- it rises proportional to the volume of air passing through the intercooler per unit time. More airflow, more pressure drop.
So what was happening is that the WG was indeed holding a constant pressure in the system before the intercooler, since that's where its reference signal was. After the intercooler, the pressure dropped with RPM because airflow obviously increases with RPM. As the RPM climbed and the mass of air passing through the I/C increased, the pressure drop across he I/C increased and this was reflected in my MAP gauge.
Installing the larger can helped somewhat, and it's obviously a beefier unit- it was not cost-burdensome and I'm glad I put it in. But installing a nipple in the pipe between the I/C and the TB and feeding that into the MBC and WG was what really made the boost rock-solid.
AbeFM gave me the answer, which in retrospect seems blindingly obvious but at the time hadn't occurred to me. I was still taking the WG boost signal from the stock location on the compressor- before the intercooler.
The intercooler is a restriction. Thus, when air is flowing through it there is a pressure drop between the inlet and the outlet. The amount of this drop is not a constant- it rises proportional to the volume of air passing through the intercooler per unit time. More airflow, more pressure drop.
So what was happening is that the WG was indeed holding a constant pressure in the system before the intercooler, since that's where its reference signal was. After the intercooler, the pressure dropped with RPM because airflow obviously increases with RPM. As the RPM climbed and the mass of air passing through the I/C increased, the pressure drop across he I/C increased and this was reflected in my MAP gauge.
Installing the larger can helped somewhat, and it's obviously a beefier unit- it was not cost-burdensome and I'm glad I put it in. But installing a nipple in the pipe between the I/C and the TB and feeding that into the MBC and WG was what really made the boost rock-solid.
#34
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,339
Total Cats: 6,793
I used a 1/8"NPT to 3/16" brass hose barb fitting from ACE Hardware. Drilled and tapped a 1/8"NPT hole in one of my pipes and just threaded it in.
I mean, either way to can tweak it in software- if it's closed loop than the MS will handle it, if it's raw DC then you'll just have to scale the numbers down a bit towards the top. But I think it'd be easier to do with the drive air from a post-IC location, so that there's a linearer relationship between it and actual MAP.
(Is linearer a word? More Linear. Linearer. Yeah, I like it.)
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