[fkemmerer]

Originally Posted by FUNFER2

Hello guys, I'm asking here for opinions and advise. I have 10 k to spend on my cobra and I have two choices.

Dynatek stacked EFI-

The Webber's in a Cobra have always turned my crank. When Dynatek came a long with it's Webber look a like EFI, I got very excited. Although I was confused about their computer being self learn, a few of you eased my mind & told be how it works. Now it sounds like a great product and looks fantastic. If I choose this option, I would like to polish, powder coat, ceramic coat and anodize some of the parts. It is very expensive though at apx. $6,000 + the pump, lines ect.....

New short block-

My 428 is a .060 over block. I haven't had any issues at all and it performs very well and sounds awesome. I would like a new aluminum 427 side oiler,..... just because, ya know what I mean Vern. I can not afford a RTR motor from Keith, George or other FE builders.

I'm thinking about using my 428 as a donor and buying a big bore for more cubes, short block, stage 2 Edelbrock alum. heads, larger cam and larger cfm carb. if needed. I have a Vic Jr. polished and ceramic coated intake, BG Mighty Demon carb. MSD 6-AL, Canton pan ect. Everything should swap from my 428.

600 + HP/TQ is my target, like many of you have. I have no problem lashing a solid roller valve train. I want it big & nasty for the street. I know the cam selection can be talked about forever but, that's not the issue yet.

I can assemble the short block or have the bottom end done by the engine builder. What would Keith's apx. cost be ? (I know, a lot of variables) just apx.

So I ask, what would you do with a 10k budget ?

New more cubes engine (hope for a alum. but, iron is not out of the question)

OR

Keep what I have, and buy the Dynatek EFI, and make it all pretty & cool looking. It should bring up the HP/TQ a.... little.

I'm sure a lot will advise a alum. 427 and more power but, the EFI is so,...cool for $6,000, unless I can talk them down. And some will also say, "it's your choice", but I'm asking what would you do.

Thanks, and let the fun begin.

Hi Kevin,

I think that the best answer to your question might depend upon what you want to do with your car. If your car is mostly street driven and you are pretty happy with the power levels that you have now, then I'd recommend the EFI setup for the looks and for the likely improvements in drivability and throttle response (and perhaps power) that you'll get. If you want to race your car and light weight is a prime goal, then the aluminum motor would be the way to go. If your car is mostly a street piece, I think that there is a middle ground that you should also consider. You will get most of the weight savings and a big boost in performance if you upgrade your 428 with a good set of aluminum heads, a well matched hydraulic roller camshaft and the EFI system. This combination should provide pretty significant increases in torque and horsepower as well as give you the WOW factor of the EFI setup.

If you go the aluminum motor upgrade route and your car is street driven consider this - if you use a radical camshaftyou will get a lumpy ide the the "mean sound" that you are looking for but this wil probably come at the expense of low RPM performance and overal drivabiity on the street assuming you are running a carb. Much of this could be fixed with EFI but doing both probably won't fit your budget. If you are driving your car on the street and you feel you need more performance than a good set of aluminum cylinder heads and a hydraulic roller cam can provide, then it would be better to go the stroker route to get the power. You will end up with a much more streetable combination this way.

I am a big fan of EFI systems and have built several motors including an ERA cobra with this approach. I have also built several fairly radical motors with carbs over the years. While its true in theory that you can get just as good of a tune with a carb as EFI, I've found that things seldom turn out this way in practice. The more radical the cam, cyclinder head, induction combination gets, the more this is true. The problem with a carb is that each tuning change effects a very broad area of the fuel curve. This means that a change to solve a problem in one situation likely creates compromises in performance somewhere else. The advantage of EFI is that you can make very localized changes in the fuel and timing maps of your motor and only the areas you are targeting are effected. All of this results in better throttle response, much better part throttle and transient peformance, and usually a better overall tune/more peak power. All of these things are not too important in a race motor which is operated close to WOT and peak power RPM most of the time (some road racing scenarios are an exeption to this). In a street motor however, the fun factor is almost totally about driveability at less that full throttle outside the peak power band. This is where EFI really shines.

I have a website that includes a little more technical information about the projects we've done with EFI. You can check it out at:

http://www.anitafred.net/HotRod.htm

No matter what you decide to do, I'd recommend that you talk to and work with Keith Craft (he's on this forum) on your project. He did the motor for my Cobra and I'd recommend him for either route that you're considering. Keith is very pragmatic about what combinations work best and he'll help you get the best bang possible for your buck once you know what you want to do.

- Fred