BUICK 350ci and Howell TBI

[DKing29874]

I'm tired of having to adjust my carb when I go from 5000 Feet to 13000 when wheeling in the mountains. I called Howell to talk about their TBI kit for the 350 Buick. I was told the package they have is a 2 barrel TBI and its make me a little cautious about the performance. Do any of you run the Howell TBI and if so how is the performance more on the freeway than when wheeling. Any input is appreciated.

[Hurcules]

Ditch the Howell idea. www.customefis.com is the place to get TBI. I bought John's setup and put it on my 327, and it is just awesome. I did a lot or research and John's kits just have too many advantages over howell. Howell does not have any ability to control timing, and you cannot burn a chip for it to get it dialed in correctly, it will never be optimized. During my research I also found a few people with instalation issues, the hanress did not really impress me as far as quality, and my friend with a Howell setup on a AMC 360 still only gets 10 MPG.

John got my kit to me and I was very impressed with the complete deal, everything from the fuel line, pump, wiring is all top notch and all there. His harness is super clean, and for the most part stand alone. There were only 4 wires to hook to the Jeep, one to the battery, one to ground, one to the ignition switch, and one to my tachometer. Everything is preterminated, just plug and play. It runs great, I am sending John a diagnostic file this week to get the chip tuned to my motor to it is optimized. I have not run through enough gas yet to calculate my MPG, but at a guess it is around 15 mpg, up from 9 mpg with the holly 650.

Custom efi's has one very happy customer here. [img]images/graemlins/cool.gif[/img] I can snap some pics if you want. All setup with everything including a new distibutor, cap, rotor, and wires I came in under $900. [img]images/graemlins/cool.gif[/img] [img]images/graemlins/40BEER.gif[/img]

[GRQster]

Yo Don,
This reply would fall under "any info is appreciated", I hope,.
I used a Howell wiring harness and some other goodies for my 4.3 install. I am a flatlander compared to you but Howell has never led me wrong. Service after the sale has been free and excellent.
Ever thought of an adjustable fuel regulator?

[GRQster]

Who'd a thunk it? Me and Hurc posting a reply to the same post at the same time? And on opposite ends of the issue! Go figure. [img]images/graemlins/grin.gif[/img]

[Hurcules]

GRQ, the thing with the 4.3 is that you are only using a harness from howell right? The TB unit and the computer are already setup from the factory to run the 4.3 because in most cases it is a factory fuel injected motor. On the buick 350 and many of the later V-8's you are starting from nothing, there is not a computer with the right programming to run the engine right. It will run, but it is is like a bad carb. Howell does nothing as far as the programming is concerned on a 4.3, they just make a cleaner harness without all the factory wires not needed for a swap.

On the issue of throttle body size, the 2bbl is fine for mild horsepower, anything over 300 horse power I would step up to a 454 throttle body. My 327 runs a bit over 300hp and I do feel some restriction, but I really don't care for huge HP numbers anyway. The 650 carb was a bit too big and it stumbled a bit with low vacuum on take off. That problem is gone now. [img]images/graemlins/RockOn.gif[/img]

[dave]

When there is discussion about a TBI and engine performance, the simple fact of the matter is the Chevy 350 TBI is rated to flow 505 CFM. [img]images/graemlins/frown.gif[/img] In the early 90's Chevy produced TBI police cars that showed very impressive performance. The PROM chip for the police car had an agressive timing curve and the police car fuel injectors had a higher flow rating. The early 90's Chevy pickups with a 454 had 2 barrel TBI's that flowed nearly 670 CFM, but don't quote me on that, I'm not 100% positive about that exact flow rating. The 454 2 barrel TBI has larger diameter throttle blades, so it easy to assume the 454 TBI has a higher flow rate.

As already mentioned, the TBI system needs a reprogrammed PROM chip if the TBI is not being used on it's original engine. The stock Chevy van / pickup 350 TBI will work with a Buick 350 engine without modification. The GM TBI computer can learn to work on engines of nearly the same size of it's original engine, but it's learning is limited.

It's likely going to take some additional time and money to get a TBI system working as good on a Buick 350 as the TBI system did on a Chevy 350, but the conversion should be a very good system once all the details are worked out. [img]images/graemlins/smile.gif[/img] There are aftermarket 4 barrel intake manifolds for the Buick 350, and after market TBI to 4 barrel adapter plates to help the performance of a Buick 350. The factory 2 barrel intake manifold is somewhat limiting if a Buick 350 is going to make 1 HP per cubic inch.
dave

[img]images/graemlins/goodpost.gif[/img] by the way.


I'll chime in too. Go with a customefis kit. We have worked with him a lot on various TBI systems on different type motors and he really knows his stuff. He'll build you a good running kit.

[Hurcules]

The real beauty of the custom efi's kit is that it will not take any more time or money to make it work on a buick 350. With the purchase of the it you buy Jonh's time to make you a new e-prom, however many times it takes to get it right. You just need a laptop computer to plug into the efi harness, then go driving while the computer collects data. Then e-mail john the file, and the new EPROM chip comes in the mail. All the parts are stock chevy truck parts too, any parts store around has everything in stock if something were to fail. The kit comes with adapters to work with whatever intake you have. Unless you have a very tricked out 350 you do not need a 454 TBI. Remember that the stock HP numbers for the Buick are in the old standards, not today's.

[GRQster]

Yeah, I know,
I just used the wiring harness and a chip for the factory setup. I was just relaying that I had good experience with Howell. [img]images/graemlins/RockOn.gif[/img]