I noticed that your belt tensioner is on the leading side of the blower. This should be avoided. The tensioner should always be placed "behind" all high load items (A/C compressor, Blower, Alternator) as it is meant to take up any slack on the back end. With the tensioner placed in front of the blower, any belt tension rise produced by the blower will compress the tensioner spring, causing the back end of the belt to loosen up and slip. Hope this makes sense.
Same message but difference in naming convention - I would say the tensioner should always be in front of major accessories. "In front" references the direction of belt travel, so the belt goes to the tensioner before it gets to any large accessory load, which places it on the low load side of the belt immediately following the crank pulley. In this install the belt goes from the crank pulley to SC, tensioner, water pump, alternator, then back to the crank pulley. So the tensioner should be between the crank pulley and the SC (where the other idler is).
Now if he replaced the spring loaded tensioner with a mechanical tensioner that locks into position it would work as well.
Here are two videos of it running at 2500rpm. One of hte videos i simply had the tb clamped on, The other i made a gasket for and put 1 bolt in until i can finish my adapter plate.
I must have a leak somewhere as the rpm starts to race and smells really rich.
No evap can hooked up, no egr hooked up, no pcv valve.
Tightened up some bolts on the intake manifold to throttle body adapter. Helped a little bit. Idling at 1000rpm and pulling 15 vac. enough vac to spin the supercharger w/o a belt. I tried blocking off 3/4 of the throttle body and starting it, and it wouldnt start.
Definintely a misfire, maybe a couple cylinders are missing and dumping fuel out the exhaust. Running very rich! I let it run for 2 mins and the rpm eventually increased to 2250.
Im going to check some plugs maybe or throw the oem throttle body on there.
.... I don't think you need to put check valves on anything except for the power booster.
The throttle side of the supercharger will never have boost anyway.
I wouldn't put check valves on the MAP sensor or fuel regulator.
If you put a check valve on these.... they will always read high vacuum.... and will cause a lean condition when you open the throttle beyond idle.
Thank you. I wasn't sure what to do. I was thinking about how the MAP sensor and EGR function all day yesterday. EGR might still need a check valve so it doesnt see boost I think.
I was thinking the oem fuel regulator should have a check valve though, but if the top vacuum tree only sees vacuum it should be ok.
Booster has a check valve on the booster its self. You don't have to worry about it seeing boost. In my turbo car I made no changes. You could drill and tap for a hose barb into the supercharger neck between the TB and Rotors for a vacuum source that never sees boost or use the vacuum tree.
Thank you. I wasn't sure what to do. I was thinking about how the MAP sensor and EGR function all day yesterday. EGR might still need a check valve so it doesnt see boost I think.
I was thinking the oem fuel regulator should have a check valve though, but if the top vacuum tree only sees vacuum it should be ok.
The vacuum hose to the EGR valve should come from the EGR solenoid.... and there should be another vacuum line from the EGR solenoid to the vacuum tree.
.... I'm not sure if the EGR is going to function properly in your setup....
Your EGR valve is located in the boosted lower manifold.....if the EGR valve is open during boost.... and if the boost is higher than exhaust pressure...
....then some boost will leak away into the exhaust system.
On the 3800sc.... the EGR valve purges the exhaust gases into the throttle side of the supercharger.... the side that never has boost.
Excellent point! Having the EGR after the supercharger would still have it open during cruising speeds though? I'll probably end up blocking it. Just annoyed by the check engine light.
I wanted to share an idea I had for a shorter distributor cap with remote coil...
As you probably know, there is no "crab cap" available for the 4.9 distributor But maybe one could be made....from two distributor caps.... The closest thing to having a remote coil for the HEI distributor was the cap that was available on the 1976 Blazer with a 6 cylinder engine This cap will fit the 4.9...you would need to remove the four "hooks" and use screws to bolt it to the 4.9 distributor .... and of course you would need 8 terminals...not six So cut out the center section of this cap.... and insert a cap from a 1996 vortec V8. The vortec cap would need to be shortend a little and set in dead center and clocked correctly. use the rotor from the 76 .... and presto! ....you could have a low profile cap
.... and then, you could lower your supercharger some more to fit under the hood better.
.....just a thought.... here are some photos of what Im talking about....
cut out area inside yellow circle
[This message has been edited by MaxCubes (edited 04-21-2013).]
I like the shorter cap idea, but it probably would be better to make an adapter ring that bolted to the 4.9 distributor and accepted/centered the stock Vortec crab distributor. Since caps are replaceable items it would be best to keep them stock.
MAP and Fuel Pressure Regulator should be connected to the Intake Manifold.
Evap Purge and Power Brake Booster should connect to vacuum only sources located between the SC and throttle body.
You need a 2 bar MAP sensor and ECM programmed correctly for your application. Stock ECM programming is much more complicated than just adding fuel at some curve rate based on manifold pressure. Most likely that is going to mean a different ECM, such as the 7730. Talk to Ryan Gick of Sinister Performance for his recommendation.
You also need to have a scanner hooked up to the ALDL port and see what the ECM is reading, and then what the ECM is doing. Anything else is stumbling in the dark. Is the ECM commanding the idle to increase and thus opening up the IAC? If so why? If not then what is happening that the RPMs are increasing? Does the O2 sensor read the overly rich condition, or is it reading a lean condition and then adding fuel?
I sell the ALDL to USB cable at http://reddevilriver.com - TunerPro RT can scan both the 4.9 ECM and the 7730 ECM.
The ALDL cable can also be purchased elsewhere or hand held OBD1 scanners are also available, but if you go handheld, make sure it actually shows the sensors, not just reports on the trouble codes. I believe my cable along with TunerPro RT ends up being the least expensive, and the most useful way to scan your ECM.
Also +1 on blocking off the EGR. It would be complicated to hook up correctly and I don't think it's needed in MN.
[This message has been edited by phonedawgz (edited 04-21-2013).]
Vacuum leak through the snout bolts since some go into the air chamber. AGGG!!! Stripped one out too but somehow fixed it with a longer bolt. RTV copper on all the bolts as well.
Got it running. I can hit about 5psi so far but I think my gauge is goofy. Chewed up two belts so far also since its such a long run from the SC to the crank with only the smooth oem idler in between.
You've come a long way since I first met you... years ago, you drove 75 miles from Mankato to the Mall of America with no hold down bolt on your newly swapped 4.9 distributor and had to keep stopping to turn it back.
Keep an eye out on here, we're gonna try to get a few more MOA meets in this summer(if we ever get one) than last year. Last year we had approximately zero.
The one pictured on the first page. Northstar one I can't remember which year its from. Works great. Adapted it to the Supercharger pretty easily with a 1/4" spacer plate.
I've been doing a little work with the Cartech fmu but I think i'm missing the vent line check valve / adapter. This weekend I plan to cut the decklid if all my minor fixes seem to go well.
[This message has been edited by arte444 (edited 06-06-2013).]
All the pieces are back together once again. Cartech FMU has been installed. Drove it a couple times and its staying together in one piece finally!!! Next is to cut that damn hood to make room for this supercharger.
Dang I can't belive I lost track of this thread. I was goofing around on YouTube searching for 4.9 Fiero videos and saw your video. I was like, Wait, I know that build......... When did he finish it, and had to come search here for your new thread. Last time I read it, you were still in the (bad shops) build thread. Congrats on getting it running. If I ever get back to Canada to repair the issues the "bad shop" left my car in, I may do some sort of boost. Seeing as we have a perfectly good S2 3800 SC GTP with a blown trans, maybe I will part out the GTP and use the blower on the 4.9. Could be interesting.
------------------ 857GT Part 85GT Part 87GT Part Caddy, 93 Eldorado 4.9, 5spd Dual O2 Custom Chip, Custom Exhaust. MSD Everything Now with Nitrous. Capt Fiero --- My Over View Cadero Pics Yellow 88GT 5spd Full Poly Suspension, Lowered 1/2" in front, Corner Carver.
Measured 4lbs of boost. Just a little bit shorter than my prediction. Boost / Supercharger whine doesn't kick in until about 3500 rpm it seems. My rotors are probably pretty worn out, might goto a smaller pulley and see what happens. (BOOM)
Lots of fun. Same or more torque. Great throttle response.
I'll try to get in some donuts soon with a video =)
I noticed that your belt tensioner is on the leading side of the blower. This should be avoided. The tensioner should always be placed "behind" all high load items (A/C compressor, Blower, Alternator) as it is meant to take up any slack on the back end. With the tensioner placed in front of the blower, any belt tension rise produced by the blower will compress the tensioner spring, causing the back end of the belt to loosen up and slip. Hope this makes sense.
Rough cut the decklid. Still having trouble fitting over the snout. I don't really want to grind on that but might come up with an idea to glass around it.
Plan on using 02 wrx scoop.
Glovebox Scoop
[This message has been edited by arte444 (edited 07-10-2014).]
Anything new on your build lately? Hope shes still kickin. Between you and Max cubes, I've been getting a lot of ideas and accumulating parts for a 4900 sc build here in good ol amish country... but I got a 5.3L swap to finish on my wrangler yet so I'm just watching from the side lines to see whats gonna work the best for me between you fellas experimenting lol. I'm hoping both you and max get back on the forum and start posting again... I would def like to know what kind of hp you guys are pushing. My goal is 300-350 hp which I don't think that is completely impossible with this motor and a m90.
