Olds EFI conversion on the cheap...

[Gozer442]

So, having a personality that demands control...

...I would like more control over fuel ratios on my Olds 403. I've been looking at the MegaSquirt software, and combining it with a GM 454 TBI system to replace the Holley 750 3310 I have on it now. I'd rather not install fuel rails on the Edelbrock RPM it has, so the GM TBI looks like the least complicated install...apart from a canned Holley EFI or FastEFI system that costs thousands.

I'm an IT guy, so using the laptop to modify the tune, and work with the wiring shouldn't be to hard for me. The one thing I'm worried about is 400-425HP with oversized valves in 455 heads... I'll need the same or better volume the 750 produces... will the TBI be a limiting factor?

At the end of the day, I want to learn about EFI tuning, get some added consistency, and increase performance by proper tuning.

Who has some ideas, some real life examples? Thanks!

 

[olds307 and 403]

You can get bored out versions even larger than 454 TBI. The later 350's tbi sensors are more common and cheaper. I had tps issues with the 454 TBI on the Olds 350 powered 94 4x4 than ran TBI. It made a big difference in power over the modified by me stock unit. I ran the 350 injectors, 454 injectors require twice the pressure as the 350 injectors to flow their rated pounds per hour.

 

[64nailhead]

The BBC TBI units aren't a real performance upgrade. They are rated in the area of 650 cfm, which is fine for 300-350hp motor, but at your HP level they might be underrated. Persoanlly I wouldn't do use one on your build unless cruising was the main use. On the dyno or strip it will be disappointing.

http://www.jegs.com/i/Holley/510/11...wm6DEFe9scC8UNCvLdwV3HPtMvjpqJfeqpRoCZETw_wcB
or
http://www.ebay.com/itm/Polished-Bi...ash=item25b1c659f1:g:DgIAAOSw8-tWU4i~&vxp=mtr

would be what I would be after. Have you considered an FiTech setup. The fuel only gigs are pretty darn cheap and have had great reviews so far.

 

[olds307 and 403]

Here is what you are after. An 80's CCC 307 distributor handles the timing control as the MS is compatible with them.
http://www.ebay.com/itm/54mm-PORTED...ter-/231496036270?vxp=mtr&hash=item35e63d2fae

 

[454GrandPrix]

Have you considered an FiTech setup. The fuel only gigs are pretty darn cheap and have had great reviews so far.

x2 for FiTech. Their Go EFI 4 systems are exactly what you're looking for. They retail for $995, and there is currently a $100 rebate which brings your final cost down to only $895. That is extremely reasonable for a self-tuning EFI system.

 

[olds307 and 403]

Sounds like he doesn't want or need a boxed system. If he does, Mark Remmel is the guy to talk to, I can give you his info. He is an aftermarket EFI tech for AEM, Fast, Holley and the now gone Accel DFI. He actually owns a Cutlass Convertible with an Olds 350 with Sequential multiport EFI. He also builds Olds engines as well.

 

[Gozer442]

Thanks for all the comments!

The TBI was an initial direction because they're common, cheap to assemble parts, and would work with the MegaSquirt. With your suggestions and more reading...there are not many performance options for a stock TBI setup, and it has performance limitations. The main reason I don't want to use the canned complete EFI systems was the cost....but for under $1000, that could be do-able. The FiTech products look great!

I still think there is a less expensive solution. My goal is to piece together a carb-swap EFI solution for $500. I still don't know enough about what pieces are compatible with each other (throttle bodies; computers; sensors)...more reading to do.

.... If he does, Mark Remmel is the guy to talk to, I can give you his info.

Yes, I'd like to chat with Mark...get some insight. EFI management is definitely something I want to put some effort and resources into.

 

[CWPottenger]

If you shop around you can find the more expensive systems on the used market with low mileage and sometimes half the cost of new. When doing a EFI swap for a "non mainstream" build it can be helpful to have a professional tech support team to ask for help. No matter which way you go to EFI, once you have it dialed in you will be happy with the improvements that EFI offer.

 

[oldmansmonte]

x2 for FiTech. Their Go EFI 4 systems are exactly what you're looking for. They retail for $995, and there is currently a $100 rebate which brings your final cost down to only $895. That is extremely reasonable for a self-tuning EFI system.

Only problem is a kit like that won't work with the factory fuel pump. It will require a more modern one with much higher pressure. Which means changing the sending unit and all the lines perhaps? Definitely thrusts that into a higher cost bracket. At the end of the day though I think it's worth it.

Gozer442 TBI advice from a guy who runs it. Totally understand your need for EFI's on the go flexibility. There will be things you'll like about TBI but ultimately you'll want a better system. If you're going to put the work in just buy a better system. I've had mine 5 years and it's coming off this spring.

 

[Mike buttafuoco]

Edelbrock also makes a throttle body that works with I believe, a megasquirt or a big stuff system. Please don't be disillusioned by the self tuning systems out there as I ran a QFI on my last car and the tuning was excrutuatingly painful. And no one around here knew how to tune it properly. Not even the tech dept at QFI. It was a big mistake on my part as the car was faster and pulled harder with the carb. Looking back, I would have gone with a megasquirt or big stuff and went with a multi port system instead of that over priced garbage. It's up to you, don't take my word as the gospel. You may get it and it works perfect for you. It didn't for me u fortunately. I sold the car with a good tune, not a perfect tune in it.