Supercharged GS400 tuning/ performance questions
yeah boost limiter valve, after the sc/before the maf, mine looks like there's a BOV right below where the hole had to be drilled for the IC piping, kinda crappy location, can't mess w/ it.
Here is a company that makes a Boost Limiter Valve (BLV)
http://www.928m.com/parts/boostlimitervalve.php
http://www.928m.com/parts/boostlimitervalve.php
Joined: May 2001
Posts: 8,702
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From: California
yes, thanks rmmgs4.
I'm also really interested in a different setup to deal with the belt slipage I will/ have encountered, with the main drive pulley being 5.25", was that on purpose, woudn't a 6" pulley have been more suitable (especially considering that it had to be made?). A 6" cogged/ 8rib or whatever no slip method main drive pulley w/ a 3" SC pulley should offer what is desired/ offer more flexibility and more power.
I'm also really interested in a different setup to deal with the belt slipage I will/ have encountered, with the main drive pulley being 5.25", was that on purpose, woudn't a 6" pulley have been more suitable (especially considering that it had to be made?). A 6" cogged/ 8rib or whatever no slip method main drive pulley w/ a 3" SC pulley should offer what is desired/ offer more flexibility and more power.
1. There is little clearance to make a pulley much larger than 5.25, atleast not without redesigning the entire belt tensioning set up.
2. The original design was for a very low boost set up that had no issues with belt slippage, so no reason for them to make a larger pulley.
Almost all the "Original" owners of the RMM SC kit, eventually modified/upgraded for more boost. Once you get down to smaller than a 2.83 pulley you are now well beyond the original design parameters of this kit.
So you're on your own to do the R & D.
As you know I have recently improved several aspects of the RMM set up including Intake and intercooler size & piping layout.
New Dyno numbers to be published in a couple of weeks.
Pulley re-design is in the works, but it will be a couple months before I have time to work on it.
Just an Idea-
Here is what JPI did to Speedaddic's S/C. It should eliminate splipage with the smaller pulley. Not sure what size pulley speedaddic is runnig
https://www.clublexus.com/forums/gs-...-inside-7.html
Here is what JPI did to Speedaddic's S/C. It should eliminate splipage with the smaller pulley. Not sure what size pulley speedaddic is runnig
https://www.clublexus.com/forums/gs-...-inside-7.html
hey thanks gill, I'll look through that thread/ try to get the info, although, JPI hasn't been too interested so far since they did this stuff so long ago. On another note I've ordered both my tc and headers. The shop I'm having install them is wondering about the header bolts and if they are the same size (direct bolt on headers) this is what I told him but he wants to be sure, he doesn't want to deal with header bolts breaking etc. and then having to remove the head etc.
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update: first belt snapped!
well I may have figured out why that belt snapped, I put a new belt on and after tightening down the smooth tensioner pulley (the one attached to the bar that adds tension to the pulley), I started the car and noticed it was sticking. Then I pulled it off and hand turned it and it didn't roll like a skateboard wheel with good bearings and proper lube but it didn't stick. So I put it back on and tightened it down, then loosened it till it wasn't sticking but saw that it must be damaged cause it would only not slip when it was a little too far off the brackt (ie loose). I'm also wondering what size the crank shaft pulley is so I can calculate my impeller speed. So I need crank shaft pulley diameter, ps pump pulley diameter/ attached sc drive pulley diameter (same size I believe) and with that plus the sc pulley diameter i should be able to calculate the impeller speed at whatever rpm.
well I may have figured out why that belt snapped, I put a new belt on and after tightening down the smooth tensioner pulley (the one attached to the bar that adds tension to the pulley), I started the car and noticed it was sticking. Then I pulled it off and hand turned it and it didn't roll like a skateboard wheel with good bearings and proper lube but it didn't stick. So I put it back on and tightened it down, then loosened it till it wasn't sticking but saw that it must be damaged cause it would only not slip when it was a little too far off the brackt (ie loose). I'm also wondering what size the crank shaft pulley is so I can calculate my impeller speed. So I need crank shaft pulley diameter, ps pump pulley diameter/ attached sc drive pulley diameter (same size I believe) and with that plus the sc pulley diameter i should be able to calculate the impeller speed at whatever rpm.
Last edited by gs400 civi; Jul 15, 2009 at 12:18 PM.
It seems like a decent low$ piggyback for our V8 if you don't have to add a lot to it.
I have the split second but taking it off. I'm taking it to the same place that did mrexecutive's ride down in Houston. Going with the F/IC 8. It can control injectors 100% bigger than the stocks so the 440cc should work perfect.
GS400civ, not sure how we can help. Did you install the SC yourself or was it already on? Did you just replace the old belt because it was worn?
GS400civ, not sure how we can help. Did you install the SC yourself or was it already on? Did you just replace the old belt because it was worn?
it was already on, I replaced the belt, finally got above 7lbs, like 7.9 and still slipping a little, I'm slowly tightening it, hope it doesn't break. If I can find the more info on that different tensioner setup I'll go that rout. I was thinking, of getting a larger diameter tensioner pulley to increase surface contact on the SC Pulley.
Another Update: fixed the tensioner pulley, turned out that a washer was put on backwards and causing it to sit uneven, guess the belt was loose before so it didn't matter. 
I ordered a new tensioner bracket/ pulley, hopefully I can get it so that i can get more surface area contact on the sc pulley. once I get it in, I hope to make 10lbs
Finally hit 8lbs, 8.6 actually
my torque converter came in but my headers won't get hear till next week at least
I ordered a new tensioner bracket/ pulley, hopefully I can get it so that i can get more surface area contact on the sc pulley.
once I get it in, I hope to make 10lbsFinally hit 8lbs, 8.6 actually
my torque converter came in
but my headers won't get hear till next week at least
it should be fine at ten pounds right jeff? it was the washer on the contact side of the tensioner pulley no big deal. oh what's up w/ the projectors? and I should be able to ship you a laptop to use for the carputer this weekend or early next week
Last edited by gs400 civi; Jul 17, 2009 at 12:07 PM.