Some nice fabicating skills have been exhibited on this post. Just a few comments. How will you address the supercharger sealing/gasketing? This is even tricky on the 3800SC's A 3" pulley causes KR's on a 3800SC. Will it work on a 9:1 C/R engine? Tuning- just about any GM ECM can be tuned but editing software for the 4.9L Computer may not be available. All and all its nice to see members breaking new ground here.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Some nice fabicating skills have been exhibited on this post. Just a few comments. How will you address the supercharger sealing/gasketing? This is even tricky on the 3800SC's A 3" pulley causes KR's on a 3800SC. Will it work on a 9:1 C/R engine? Tuning- just about any GM ECM can be tuned but editing software for the 4.9L Computer may not be available. All and all its nice to see members breaking new ground here.
Yes, one of my biggest concerns was sealing... I sprayed copper sealer on the supercharger gasket and plenum mating surface to try to make sure there are no vacuum leaks
Yes, 3.0 pulley is quite a bit smaller.... The 4.9 has 9.5 to 1 compression... I will have to run high octane for sure..... after some test runs and tuning, will find out if I need a different size pulley.
I am running a 7730 ecm and prom from a 1991 camaro Z28 305 tuned port injectiuon.... much more editing software available for this ecm
Nice work Max - love the ingenuity! I'm with you on the junk yard engineering. That's half the fun - mix and match parts to achieve the results. Not all of us have a mega machine shop and unlimited funds to build our dream car. It's guys like you that started the whole "Hot Rod" culture. Thanks for sharing your adventure.
How precisely were you able to maintain flatness and parallelism between the two mating surfaces of your blower to manifold adapter? Have you measured with micrometers or dial calipers?
Flatness will directly affect sealing. Parallelism shouldn't affect much other than neatness of presentation.
The Caddy 4.9 computer *IS* tunable. Tunercat has the definition files for it.
The behavior you described with and without the bypass valve is exactly as expected.
How precisely were you able to maintain flatness and parallelism between the two mating surfaces of your blower to manifold adapter? Have you measured with micrometers or dial calipers?
Flatness will directly affect sealing. Parallelism shouldn't affect much other than neatness of presentation.
I don't understand how you would have any issues sealing in 7-10lbs of pressure. Looks like he started with some thick flat steel as well.
Some nice fabicating skills have been exhibited on this post. Just a few comments. How will you address the supercharger sealing/gasketing? This is even tricky on the 3800SC's A 3" pulley causes KR's on a 3800SC. Will it work on a 9:1 C/R engine? Tuning- just about any GM ECM can be tuned but editing software for the 4.9L Computer may not be available. All and all its nice to see members breaking new ground here.
Interesting build. He has more courage than I do to go into untested waters. Anyway, since this is feeding a 4.9 vs the 3.8, I would think he will not have to worry about the boost getting too high? we will see...
I don't understand how you would have any issues sealing in 7-10lbs of pressure. Looks like he started with some thick flat steel as well.
Its not the pressure that's the problem. On the 3800Sc engines extreme care must be taken when installing the supercharger to the LIM. The torquing of the supercharger bolts must be in proper sequence and tightened to the torque spec slowly all while rotating the supercharger pulley by hand to insure that there is no binding. The slightest bit of mess up, the supercharger case twists and a leak results. In this case the fabricator here seems to have done the install properly so its not an issue. As for the crank pulley on the 4.9L vs the 3800; they should be the same diameter. IMO, the main issue now is tuning.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Watching this thread as well, Makes me want to do this to my 4.9, just don't have an Allante intake. :/ Another issue is, I'm using the Caddy ECM, and as I have read it doesn't have any provisions for boost in the parameters.
Great work so far!
EDIT: I found out though RockAuto, that the 4.9 crank pulley is 7.375" in diameter. The 3800 crank pulley is 7.156" in diameter. So yes it will be tuning even faster. IMO, I think a 3" pulley is a bit too small to start off with, to be on the safe side, because of the higher compression and a slightly larger crank pulley.
[This message has been edited by mattwa (edited 03-30-2013).]
Subscribed as I'm installing a 4.9L. Turbo might produce more HP, but SC gives better show quality. Looking forward to seeing how this goes. Keep up the good, price DOES matter, work!
------------------ Life is just SO much better when you own AND drive a Fiero!
