Doug@C&L

Hey guys,

I've been working my entire holiday weekend to get this dang car straight. Mind you it is a stock 05' GT with 3K miles and a Vortech Aftercooled HO kit.

First off Vortech needs to address a few issues. I didn't do the installation of the kit but rather picked it up from the dyno when his a/f ratio was going to 14.5:1 at 4500 rpm's with the stock Diablo tune.

After doing some research into the car I found the fuel pressure was running low under normal driving and got even worse when you got into it. I pulled the fuel pump out and found that Vortech uses a Piggy-Back Walbro intank pump hose clamped to the stock GT pump. Now even after reading the instructions I couldn't beleive it, the instructions say " Install the 86-97 Walbro Fuel pump..." clearly they know it wasn't designed to run on a electronic returnless system but yet they do. Next was the way it got it's power was herasy to me, scotchloced it to the power wires for the stock pump. Wow, let's think about this, the stock pump uses a variable voltage to maintain a fuel pressure and now it's loosing most of the amperage to a constant voltage pump running there beside it.

How did I fix it you might ask, I put a stock 05' GT pump in it and that solved the fuel pressure issue. Funny thing, I unplugged the Walbro pump from the stock pump and tried to run the car and it wouldn't even start, kinda like the scotch locks had cut the wiring in two going to the GT pump.

Well I thought that was it entirely but I was still wrong, now the car would goto 5300 rpm's and then the fuel pressure would drop off and of course the a/f would follow going lean. I contacted a few fellow SCT dealers and got some ideas and finally ended up rewiring the entire system.

I ran a # 10 wire from the battery to the FPDM and another #10 wire from the FPDM to the Fuel pump. Now of course I ran relays and fuses I just dont wanna go too indepth. Took me most of the day to wire it.

This took care of the fuel pump issues but the a/f was still going off the chart. So after a few hours of tuning and testing I finally got it right. I did have to use the Mafia MAF extender that came with the kit as it was pegging the meter in the 4" housing.

All in all It was a True PIA. I can only wonder what people are doing that just buy one of these kits and install it following all of the instructions and never take it to check the a/f ratio. BANG! is all I can say, this car seen it's share of 14.0 and higher runs with the stock tune.

I'll have some dyno numbers tomorrow, I plan on stopping it at 450 rwhp as I dont feel safe running the stock pump any higher. We'll see.

Later Doug.

P.S. Make sure you have good brakes or larger then stock tires with this kit in good form, slowing down from a 3rd gear 6,000 rpm plus run is shaky without them but BOY is it fun on the way up!

don_w

Darn, Doug... that's some scary stuff. Glad you saved this guy's car before it grenaded on him.

I also now know why you haven't replied to my e-mails...

Edited by Brad. Don't bypass the language filters!

thestoogeo

Thanks for the information. Did you just rewire the new stock pump or did you add any kind of electric boost a pump? I just installed a ProCharger kit and it came with a boost a pump, basically just a voltage regulator. I'm waiting on an update to get my Predator to work with the 06 Mustang so I haven't had a chance to run it much or get a tune. I have also installed a MAFia as I didn't have to extend any wires and its there if I need it. Glad someone else sees the need for a BBK. Thanks again for sharing.

Jon

Doug@C&L

YES, you will need the boost a pump if you are running the stock wiring. Wire it in before the FPDM and I would even recommend still running a #10-12 guage wire from the FPDM to the fuel pump. This car is running the stock GT pump(Focus) and thepump duty cycle is running at 47% at WOT and full boost, before it was hitting 100% well before then and dropping fuel pressure.

The main thing to remember with this is that the wiring to the FPDM and to the Fuel pump is a measly 16 gauge or even smaller. You are putting a huge load on any pump and being that it is voltage, or current regulated a 16 guage wire can't move that kinda amperage. So it you add a boost a pump you'll be adding even more of both so you definatly need to think about this upgrade.

As for emails, I took the Holiday weekend off, I dont even wanna open my inbox this morning,hahaa. I'm going to the dyno first and sending out 17 X-2's then I'll come back and answer emails until I fall asleep or my head blows up first.

Call me if you wanna chat...

Thanks, Doug.

Doug@C&L

Hey guys,

Just got home from a long day. The dyno session went great, funny thing was when we got there it was barely making 350rwhp and there was an older guy there saying I'd never make 400rwhp from it. Two tunes later I was at 400rwhp exactly, the following tune we made our limit, 444 rwhp and 387 rwtq. I stopped there because of the fuel system he had and he was still using the stock spark plug and stock gap. I know we could have went higher but he was a happy camper and I was just happy it went well. The a/f was perfect at 11.8:1 at 6500 rpm's with the fuel pump duty cycle at 46%.

Now for Project Source Horse!

thanks, Doug.