Fuel pressure needed some help... so installed a Magnuson Magnavolt with modified late C5 Hot Wire Harness from Caspers.

This pic shows an 03L-04 C5 Hot Wire fuel wire harness.


This pic shows a closeup of the late C5 configuration... where it ties in above the fuel tank bulkhead.


This pic shows a closeup of the late C5 harness after reconfiguration. First off the late C5's fuel wires are reversed as compared to the trucks (04-up?) Second, the tie in connectors were backwards. So, I needed to buy some pins and reconfigure the GT 280 connectors.


This pic shows the nice weatherpac relay that comes with the C5 harness. Cleaned off some of that nasty frame wax and mounted the relay on the fuel vapor cannister bracket next to the tank. Also tied in the additional ground there. Then I spray painted the area black to help protect the ground connection from the elements...


Mounted the Magnavolt on the side of the Fuze box. The power wire goes directly to the alternator.




I teed the Yellow Magnavolt wire into the grey fuel pump wire. I teed the wire because I still need a fuel voltage signal to travel to the coil side of the relay down by the tank.

The hot wire for the C5 harness was connected to the Grey wire of the Magnavolt.

I teed the White Magnavolt wire into the white Tach wire for my truck - PCM Connector 2 (green) Wire #10.

The Power wire of the Magnavolt was connected directly to the alterantor... and I founf a good spot for the Magnavolt ground.

Overall I am happy with the Magnavolt performance. When I stab the throttle I pretty much start losing fuel pressure (start is 54psi on my Autometer Gauge) right away. The Magnavolt kicks in at about 3psi of boost and about 3K RPM. The fuel pressure drop then stops... meaning it hovers at about 48PSI but the big thing is that it does not continue to drop. If I stay on the throttle and allow the tranny to shift the fuel pressure will bump to 50 and stay until I lift. I had my tuner, NicD, verify my tune today with the bigger T66 turbo and the Magnavolt / Hot wire setup and I am VERY happy to know I STILL have ZERO KR

Next up is the 60lb injectors sitting on my bench. Gonna try to get injector duty cycle back into a sweet spot...

Big thanks to BlownChevy!

Bill

 

nice write-up Bill. You decided to mount it off the rear side of the fuse block instead of the top huh?

 

what do you need the hotwire kit for im am going to be installing a magnavolt on my truck and was just wondering

 

Thanks guys...

The hot wire kit is more designed, by itself, to supply a direct voltage from the alternator... on top of a bigger gauge wire. I think its a nice compliment to the Magnavolt. I am going to pass along the info back to Caspers. It might be a nice upgrade to dual intank guys.

Bill

 

Nice work, I am glad it worked out for you! They used to do that SAME mod on the GN's back in the 80's, works very well !

 

Ya, I did the Hot Wire mod to my 85 Vette... worked great with an intank upgrade. I'm gonna see how far I can push this setup with 60lb injectors...

Bill

 

completely irrelevant, but is that the stock exhaust manifold on the driver side?

 

Yes. I had a header on there that came with the turbo kit but it slightly rubbed the steering shaft... and drove me nuts. The kit was fabbed up on an AWD truck with Hydraboost... so the steering shaft location is different. I am going to modify a steering shaft and put the header back on at a later time...

Bill

 

Sounds good, i thought that kit came with the tubular header. you must be just as **** as i am about small stuff

 

Just out of curiosity, what made you choose the C5 harness over the F-body harness? I did the same mod, but with an f-body harness that I modified. Works good!