Best aftermarket EFI?????

Grant Garrison · #1 (**permalink**) 05-12-2001, 09:20 PM

Thanks to everyone who responded to my "Single vs. Dual Plane" question (sounds like single plane for me). Now I've got another question a little upstream of my manifold....

I'm building a SVO siamesed-bore Windsor 351 bored/stroked to 427 cid. I've decided on EFI for cold/hot Michigan days, along with stumble-free performance at all times.

My question is, who makes the best EFI brains? Now I realize I could go big bucks and do Kinsler/Electromotive/Motec but have exhausted my budget. I'm thinking of doing a throttle-body for induction coupled with multiport injection built into the manifold. This leaves me with Accel or Speed Pro engine management (or???). I would love to do the Weber-like stacks, but it looks like we're adding LOTS of $$$$ to do so.

Who has the hot electronics out there? Is it worth the extra money for the closed-loop systems?

Thanks!

camcojb · #2 (**permalink**) 05-13-2001, 09:57 AM

I run the Speed Pro unit on my SPF. I also run it on a 69 big-block Camaro. The Accel DFI isn't a bad unit but it's slow to program, wants to be re-programmed if the weather (humidity) changes, doesn't have altitude compensation, and doesn't use a wide-band O2 which gives you full-throttle closed-loop operation.

I've seen both units tuned on a chassis dyno many times. The Speed Pro is dialed in with two or three pulls. The Accel takes 6-10 pulls. Also the tables load VERY slow. Now they have a new computer coming out and it is probably much improved.

The closed-loop operation will give you better driveability and mileage in my opinion. With the wide-band you can keep the closed-loop on even with full throttle which if your tuning is a little lean the computer will add the fuel you need to prevent running too lean and possible engine damage. The wide-band can accurately rear a wide range of A/F ratios which you'll be in between full-throttle and cruising. The standard O2 can't read well away from 14.7-1. That's why the factory computers without wide-band go to open loop under full-throttle.

My small-block (Chevy) in the Cobra runs Hilborn port injectors. It makes almost 600 h.p. and is EXTREMELY smooth even with a solid-roller cam with 264 duration at .050. This car would run COMPLETELY different with a carb.

Jody

Grant Garrison · #3 (**permalink**) 05-13-2001, 05:17 PM

Jody-- Thanks so much for your informative reply. As I understand it, Accel is just now introducing a closed-loop system. Sounds like it's worth the extra $$$ for wide band.

coyled · #4 (**permalink**) 05-14-2001, 10:38 AM

Grant, go with the speed pro. Call kinsler, they are the experts and will tell you the same thing. scott

ediamond · #5 (**permalink**) 08-01-2001, 07:45 AM

Will one of you be kind enough to pass on the Kinsler contact information please? I am considering a divorce from my Holley 750.

camcojb · #6 (**permalink**) 08-01-2001, 09:00 AM

Kinsler can be reached at http://www.kinsler.com/index1.htm

I purchased my Speed Pro unit from Fodge Engineering. They had the best pricing I found and do a lot of conversions on Cobras. Their number is (916) 714-3111. Ask for Dan or Eric. They have both single 4 barrel throttle body conversions which are the most similar to a carb set-up, use the same air cleaner, etc. and also do the custom Weber-type individual runner systems.

Jody

Grant Garrison · #7 (**permalink**) 08-01-2001, 07:03 PM

Thanks, Jody. Actually, we've already gone with the Accel DFI. We dyno'd my motor a couple of weeks ago, and got 604 bhp / 582 lbs/ft. with a demon carb. When switched to the Accel, we got 587 bhp and 562 lbs/ft. Kinda surprised about the drop in both numbers when going to the EFI, but still very happy with the results.
The motor (427 stroker-Windsor) has gobbs of torque (450 lbs/ft at 2600 rpm) and doesn't run out of steam up top. This should traslate into over 500 bhp at the wheels!

Now if I can just get my engine builder to finish the install so I can drive it!!!

coyled · #8 (**permalink**) 08-02-2001, 09:11 AM

Grant, was that dyno with the same intake? If so you should be able too make more power with efi provided the same flow, with no restrictions. Great numbers. scott.

Grant Garrison · #9 (**permalink**) 08-02-2001, 08:18 PM

Scott--

Yes, it was the same single-plane Edelbrock in both cases. We got the timing, etc. correct before putting on the throttlebody for calibration. The engine builder explained that the Demon and the manifold must have been an ideal match for each other, and that sometimes this happens. Must say it kinda surprised me, however.

Everything I've heard indicates that with carbs vs. EFI, one generally produces a bit more bhp, and one makes more torque (can't remember which is which, tho). I wanted to do EFI for the excellent cold start, drivability, throttle response and minty-fresh exhaust (dates don't like to smell like unburnt hydrocarbons).

In any event, I'm generally happy with the numbers, and this guy has a good rep for being honest on the dyno. I am looking forward to getting the car on a chassis dyno when we're done!

xcessive1 · #10 (**permalink**) 08-02-2001, 09:55 PM

grant-i was just wondering what the specs on your stroker are-i have a 351/427 and made 400 rwhp and 400 lbft of torque a month ago-i'm running vic.jr heads,vic jr intake(a restriction on this motor) roller cam. and 950hp holley-my winter project this year will be fuel injection. no mater what you'll love it. chris p.s.-i made 340 lbft of torque at 2500 at the rear wheels-about 425 motor!!! love that torque.

coyled · #11 (**permalink**) 08-02-2001, 11:01 PM

Grant, 2 things come to mind. With EFI you can run the motor leaner and make more power. Also, EFI sometimes will make more power with less timing as your combo is more efficient. Great combo both ways. good luck, scott.

Grant Garrison · #12 (**permalink**) 08-03-2001, 05:08 PM

Chris--

We started with a 4.125"siamesed-bore Ford racing 4 bolt Windsor block, with 4" stroke. Heads are fully ported and polished Canfields, which flowed a corrected 301 cfm on intake and 225 cfm on exhaust at .700 lift. Eagle rods and forged crank, Edelbrock single plane intake with 8 port-mounted injectors and topped with a 4 bbl. throttle body capped with the big oval "Cobra" air cleaner (hopefully fitting the 3" K&N filter). Finally, custom made 2" stainless headers going into stock Superformance sidepipes.

I've got to say, the wait is killing me. Here in Detroit there's going to be a slew of Cobras for the Meadowbrook/Waterford vintage race weekend.... hopefully I'll be driving in the next week or so!!

Grant Garrison · #13 (**permalink**) 08-03-2001, 05:20 PM

Scott--

Yeah, gotta say that I was a little surprised by the dropoff in hp/torque with the EFI. We kept pulling with the carb until it showed that 34-35 degrees timing made the most power, then switched to the EFI and did some basic calibrations (the laptop wizard was none other than the guy who wrote Accel's software).

I assume everyone knew what they were doing (I sure didn't) and that these results can happen (?). There is still final, in-car calibration to do for seamless running. The builder said we could have done a few more pulls and gotten it over 600 with EFI, but that it really wasn't worth the strain on the newly built motor (or the cost per hour of the calibration guy....).

My innitial goal was to double the power of my '94 Rx-7 (currently running just shy of 300 bhp at the crank) with strain-free reliability, and I hope that's what I'll have.

Rich A · #14 (**permalink**) 08-03-2001, 06:15 PM

Grant
Try Haltech. they offer UPGRADABLE AND AJUSTABLE engine management systems. Look at there Haltech F9.
www.haltech.com

coyled · #15 (**permalink**) 08-03-2001, 07:29 PM

Grant, it sound like a fun car to drive once that motor is in it. I'm still sort of curious. Does your throttle body flow as much cfm as the carb?Also, Kinsler has told me that with a carb you have to run it rich enough to cover your leanest cylinder. But, with EFI, you can run it leaner (as fuel distribution is much better) and not risk burnig a piston, which in theory should make more power. Well, so much for theory. Anyway, the difference in feel between 575 and 600 hp is probably not perceptable. You'll be hanging on as it will be a white knuckle ride either way. scott

etli · #16 (**permalink**) 08-03-2001, 07:42 PM

Hi Grant, I just got my 351W/ 427 motor today from my engine builder. I have the same block and crank combo that you have, but I went with the blue thunder high port yates heads, and the SVO single plane nascar manifold with a 750 double pumper redone by Da Vinci carbs. Its got a hydraulic roller cam, but I dont have the #s on it. engine dynoed at 640 hp /590 ft-lbs on pump gas. Now all I need is my Unique 427 cobra, and hopefully I will have that in about 2 weeks. Sounds like were going to have some fun pretty soon

BTW, I am not Etli, my comp. thinks I am. Real user name is Arubacobra

Grant Garrison · #17 (**permalink**) 08-04-2001, 07:58 PM

Scott-- Sorry but I can't recall the cfm capability of the throttlebody, but I believe it to be 1000+ cfm (it will flow more air than required, I'm told). I'm going to have to quiz my builder about all this (he just LOVES it when I show up with lots of internet questions...).

Yeah, 587 to 604 bhp is a difference of about 3%, but there's something about being able to say you have "over 600 bhp" out of a smallblock that sounds so cool. How much of that power I'll ever be able to use is open for debate. The builder has told me the motor is strong enough to get 800 bhp with NOS (for when I get bored with 587!).

Again, thanks so much for your input on this forum. I've learned a lot from your posts.

Arubacobra-- I'm jealous!! I wanted to go with Yates heads, but had to put a limit on the budget at some point. I also wanted to go with the 8-stack Weber-like EFI, but decided it was good to be able to afford to eat.... Seriously, I went 40% over budget on my dream, but am hopeful it will be well worth it. Have fun with your new toy, Aruba!

ArubaCobra · #18 (**permalink**) 08-05-2001, 09:32 PM

Hey Grant, I know what you mean when you talk about going over budget. My engine buildert spent about 70% more than I had planned. he also built the motor (1340 HP) for my prostock Ford Probe (http://www.timmcamis.com/eman_loonstra.html)and he probably figured more would be better for me. The worst part is that I also have to pay import duties to the Aruba government when I import all the Cobra stuff. This is ussually between 22.5% to 30% of the value including shipping and insurance. Thats what really sucks.

take care
Andre