so the last plenum had a vacuum chamber that shared the vacuum between both plenums. the problem is that the iac fed into this chamber, and when the iac opened it was jacking up the map values and the iac would just keep opening more and more, untill the vacuum looked right for an idle....the end result was a 2500rpm idle.
to fix this, im making a whole new plenum. in this the vacuum will come from a combined chamber of both plenums. the iac will feed into a seperate chamber where there will be an individual tubes going to each velocity stack. here is a paint diagram....
and when my camera decides to load ill show you the pics of my new supplies
87 fiero gt 5spd 3500, 1280 cam and PR, ls6 valve springs, port and polished heads, ported lim, ported uim, 4.3 70mm tb, ported trueleo headers and y pipe, 2.5 inch ex, flowtech muff, gmtuners.com prom, 7730 ecm (GAVE TO BROTHER, divorce reasons.)
96 LT4 6spd corvette. 4:10 gears, Open element intake, pcm4less tune, hurst short shifter, muff elims,
94 geo metro, 1.0l 3cyl gas sipper. scariest car I have ever driven!!! slow, ugly, slow, cheap, slow, handles like a wet noodle.
87 fiero gt 5spd 3500, 1280 cam and PR, ls6 valve springs, port and polished heads, ported lim, ported uim, 4.3 70mm tb, ported trueleo headers and y pipe, 2.5 inch ex, flowtech muff, gmtuners.com prom, 7730 ecm (GAVE TO BROTHER, divorce reasons.)
96 LT4 6spd corvette. 4:10 gears, Open element intake, pcm4less tune, hurst short shifter, muff elims,
94 geo metro, 1.0l 3cyl gas sipper. scariest car I have ever driven!!! slow, ugly, slow, cheap, slow, handles like a wet noodle.
Actually, they way you have the picture you should use that for IAC/everything no problem. My guess the last plenum had a leak or the MAP was only reading one side.
The MAP and brake booster need strong vacuum that's not shared with anything.
If the TB you are using does not have a built in IAC, then running an external one that feeds both sides is recommended.
If you are going custom I'd keep the plenum's seperate with the TB blades. Then just make a connection on the back/center of each plenum with a T that goes to the brake booster, and another for MAP farther away from that one, then a smaller one for whatever else like FPR.
New 2010 project (click image)
1994 3100 BERETTA. 200,000+ miles
16.0 1/4 mile when stock. Now ???
Original L82 Longblock with LA1, LX9, LX5 parts
Manifold-back 2.5" SS Mandrel Exhaust. Hardware is SS too.
it has an iac in the tb, but the problem is getting it to feed both plenums equally.
the map was feeding off the same chamber that fed everything else. in other words it didnt get acurate readings.
i see what your saying there, make it true dual plenums and then run a connection between the two for the map, one for the brake booster and one for fpr and one for pcv
87 fiero gt 5spd 3500, 1280 cam and PR, ls6 valve springs, port and polished heads, ported lim, ported uim, 4.3 70mm tb, ported trueleo headers and y pipe, 2.5 inch ex, flowtech muff, gmtuners.com prom, 7730 ecm (GAVE TO BROTHER, divorce reasons.)
96 LT4 6spd corvette. 4:10 gears, Open element intake, pcm4less tune, hurst short shifter, muff elims,
94 geo metro, 1.0l 3cyl gas sipper. scariest car I have ever driven!!! slow, ugly, slow, cheap, slow, handles like a wet noodle.
http://www.mez.co.uk/ms12.html
I just found that, haven't looked at it all that much but has some cool stuff I thought you might get some ideas from maybe?
1994 3100 BERETTA. 200,000+ miles
16.0 1/4 mile when stock. Now ???
Original L82 Longblock with LA1, LX9, LX5 parts
Manifold-back 2.5" SS Mandrel Exhaust. Hardware is SS too.
interesting! i havent seen that site yet.
heres what i got most of my ideas from
http://www.discovery-automotive.com/...r/DSC01633.jpg
http://www.928developments.com/manifold1.gif
http://www.gtr.co.uk/forum/upload/69...l-plenium.html
Last edited by merlot566jka; 12-26-2007 at 09:53 PM. Reason: i need a cnc machine
87 fiero gt 5spd 3500, 1280 cam and PR, ls6 valve springs, port and polished heads, ported lim, ported uim, 4.3 70mm tb, ported trueleo headers and y pipe, 2.5 inch ex, flowtech muff, gmtuners.com prom, 7730 ecm (GAVE TO BROTHER, divorce reasons.)
96 LT4 6spd corvette. 4:10 gears, Open element intake, pcm4less tune, hurst short shifter, muff elims,
94 geo metro, 1.0l 3cyl gas sipper. scariest car I have ever driven!!! slow, ugly, slow, cheap, slow, handles like a wet noodle.
you should do something like this...
1989 Camaro RS; Cammed 3500 swap, 45mm ITB's, Kitted 700R4, 3500 stall, Megashifter, 3.73 posi, EQ- LT headers, 3" Hooker Supercomp exhaust, etc...
1991 Cavalier Z24 5 speed; 13.07 @ 107.44 mph, 3500 MPFI with a few upgrades... 275 WHP
2006 Trailblazer; 4.2/Auto
2003 Avalanche Z71 ; 5.3/Auto - True Duals w/Hooker Aerochambers (DD)
i know what that's from!!!!!! mmmmhmmhmmm!
Andy
fastest 1/8: 10.19@ 67.17
fastest 1/4: 16.16@ 82.70
62mm TB, 1.6 roller tip rockers, Ostrich 2.0, UD pulley, TB heater bypass, K&N, 180* stat, No cat, 99Grand AM dual cooling fans. 4T65E swap FDR 3.69, EP LSD, F.A.S.T. transmission controller, TransGo shift kit.
Thats one of twm's injection systems on that manifold, it has the same flange faces as a set of tripple barrel webers.. I have been trying to find a cheaper set of the webers or zenith's for a couple of years now.. I had that plan after I built my first manifold, little did I know thay actualy made them..
VIDEO Acadian http://videos.streetfire.net/video/8...7f00197eea.htm
VIDEO Chevette http://videos.streetfire.net/video/9...500156e11b.htm
Six-t-Six Motorsports
2.8L Chevette Roadcar
3.2L Acadian Racecar
First manifold.. wasnt too great.. had a real stiff 3000rpm powerband, not too streetable especialy in a 1900lb car
VIDEO Acadian http://videos.streetfire.net/video/8...7f00197eea.htm
VIDEO Chevette http://videos.streetfire.net/video/9...500156e11b.htm
Six-t-Six Motorsports
2.8L Chevette Roadcar
3.2L Acadian Racecar
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