Z-Dreamer Posted January 12, 2001 Share Posted January 12, 2001 Hey Pete, have you looked at Holly's new 950 Commander Multiport EFI? You can see it here: www.holley.com/HiOctn/ProdLine/Products/C950/C950.html Mark ------------------ " Now where did I set my beer? " [This message has been edited by Z-Dreamer (edited January 11, 2001).] [This message has been edited by Z-Dreamer (edited January 11, 2001).] [This message has been edited by Z-Dreamer (edited January 11, 2001).] [This message has been edited by Z-Dreamer (edited January 11, 2001).] Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 12, 2001 Share Posted January 12, 2001 quote: Originally posted by Ross C: Their were some comments on this thread or another about 'closed loop' being v. good. I'm not in such agreement. Closed loop (correct me if this has changed) is based on your ECU trying to maintain A/F at 14.7 stoich right? Lately their's quite a bit of evidence that at cruise engines (varies among builds) can tolerate up to 17.0 A/F which leads to FAR greater mpg/efficiency, so unless you can alter the closed loop 'target' ratio I wouldn't get to excited about it. I'd instead be progressively altering my cruise/higher vacc A/F while monitoring my O2 sensor and related temps/knock etc. As usual, Ross makes some good points. I'd like to add a bit more on the closed loop thing... Using closed loop feedback can be a good thing, but you CANNOT rely on it to make up for a poorly tuned fuel delivery map. It should only be thought of as a correction for rich or lean trends. The EGO feedback should be one of the last things that gets tuned, especially if you plan to do most of your tuning on the street. The reason for this is that depending on the placement of the sensor (header collectors are a popular place), a number of engine events can go by between the time the exhaust valve opens, and the resulting gasses reach the sensor (this is usually called 'transport delay'). Also, because the slope of the EGO sensor response curve is very steep around stoich, it is difficult to come up with an accurate correction amount for the next cycle, which means that there is usually considerable oscillation that occurs before the correct A/F ratio is obtained. The oscillation can be tamed, but this usually involves slowing down the response so that the A/F ratio 'creeps up' on the desired ratio. Taking all of this into account, it can actually take as long as 0.5 to 1 second for the closed loop feedback to do it's thing. Also, if the feedback is correcting for a fuel map that is not very close, the engine can run erratically and unpredictably during this time. So, the best thing that you can do is make sure that the fuel map is really close for as many of the tunable points as you will be using. In this fashion, the closed loop feedback is doing as little as possible, and generally only correcting for long term errors. When used in this manner, the closed loop feedback is a nice thing to have. As far as I'm concerned, datalogging is absolutely the easiest way to achieve this. It's a fairly simple thing to look at the data after a run, and see EXACTLY what EGO readings you had at every RPM and MAP combination that were used during the run. From this information, it is a fairly straightforward iterative process to arrive at a well tuned fuel delivery curve. Try watching a real time display while you are trying to keep the car on the road and then remembering exactly what happened a few minutes later - it doesn't work very well. Okay, I'll shut up about datalogging now . One other thing - there are systems available that do allow targeting different A/F ratios for the feedback loop in different conditions. The TEC II is one, and I believe that the MOTEC can also do this. Not sure about the Holley or the SDS - I just don't remember. Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 12, 2001 Author Share Posted January 12, 2001 Wow! This thread has really been good. I've definitely learned a few things. TimZ, you ever thought about righting a book, or quicker yet, a tech article on EFI? Yes, I know about the Commander 950 - looks interesting. Monetary reasons and my timeline to just get the car painted and on the road preclude me from taking that path right now. But I'll be researching the EFI systems for future consideration. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 17, 2001 Share Posted January 17, 2001 I installed a projection 900 cfm system on my 350 (a zz430 crate motor clone with Gm performance part's fast burn heads, HOT roller cam and 1.6 ratio rockers) last spring. I have been generally happy with the performance, after taking taking some time to dial in. Here's the high points: Data logging capability was very important to getting the final tuning correct. I bought an aftermarket data logging software called A-Chart, which was very helpful and actually provided recommended fuel map settings after each test drive. The closed loop system on the Holley doesn't like anything other that a mild cam, causing a surging idle as the computer "hunts" for the proper setting. This is easily fixed by going to open loop mode. The closed loop can be made to function only during cruising by putting a switch on the o2 sensor. The large throttle bores and direct linkage make the 900 cfm unit "jumpy" or throttle sensitive driving around town. I'm sure this could be fixed by putting a progressive linkage on it or going to a smaller throttle body. The 85 lb injectors are nowhere near maxed out on my engine (I have not dynoed it yet, but very similar motors are putting out 415-425 on the engine dynos in the magazine tests) By the way, the holley will allow you to tune to an air/fuel ratio other than 14.7:1 by adjusting the oxygen voltage set point in the software. If you go with the multiport fuel injection made by holley, you will get a very similar software package to what I was using, with the same types of mapping functions. My personal opinion would be that for a chevy V8, the difference in performance between a throttle body setup and a port injection system is largely theoretical, and a throttle body is just as drivable in a performance application. Much more important is the manifold, throttle body and software design. I took off a Tuned port injection system off this motor to put on the 4Di because the design was so restrictive to breathing on the top end of the rev range. Not the fault of the port injection, but my point is that a bad port injection system is much worse than a good throttle body. The motor now acts like there's no such thing as a red line. By the way, it was more driveable than any carburetor I ever had on the first day I put it on. Just my 10 cent's worth. The quote: Originally posted by pparaska: I'm wondering about Holley's 4Di Projection setup. They advertise a 4 bbl one that's 900 cfm good for 350-500 hp. Jegs lists it as PN 510-950-21S. Holley's site is hosed and all the links to it that I can find are broken. A V8Z bud (Glen McCoy) that was over to help with the start of my engine the other day mentioned that he had an older version of it, and for what it cost ($500 then - a slow computer with FI only, no ignition) it was pretty nice on a 350 hp motor. I'm around 350 hp now (according to Desktop Dyno) and I'm thinking that for $1400, everything included (except for some fuel line I'd need to run, maybe), it'd be a nice upgrade from my Mt. Vesuvius carb . I know that it's not multipoint, but I'm not looking for the end all to efficiency, etc. I do want good tuneability though, and I'm looking for info on whether this system has a decent set of features that anyone is aware of from experience, etc. I'm just thinking about doing something like this in the next year. ------------------ Tony 1972 240Z w/ZZ430/T56/GTO body kit Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 19, 2001 Share Posted October 19, 2001 Darn it Pete, now you have me looking at this thing... I'll have to admit, it looks pretty good, wouldn't have to engineer anything to install it and its got to be way better than any carb and can handle to 500 hp. If its easy enough to tune I wonder how it'd do with a little boost pressing on it. I'll have to contact holley and see who's done it (not if, I'm sure someone has..). I like that it can control timing as well, very nice, probably just have to use a different HEI and at most change the distributor drive gear if its setup for a roller cam. Sure solve alot of problems huh. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 20, 2001 Share Posted October 20, 2001 "I'm around 350 hp now (according to Desktop Dyno) and I'm thinking that for $1400, everything included (except for some fuel line I'd need to run, maybe), it'd be a nice upgrade from my Mt. Vesuvius " $1400 vs. 1900 for proflo? not saying proflo is the right solution but you get a v. nicely plumbed vic. jr. efi manifold, throttle body and easy controller/tuner with proflo. I was not in favour of the laptop requirement of the 4Di. I don't alter my EFI setup daily but I will tune on it weekly. The intake and laptop quickly close that price gap (ie. sell your intake, if a good one you'll get decent dough...if not you'd like a better one anyhow). I've often been surprised at how much $ you can acrue towards a project by selling anything you're not using that others can use, ie. manifold/fuel pump/etc. PS I had a fine 4Di setup I bought for $325 in near new....still sold it to a friend as the laptop and TBI deterred me...if I was going to spend time going EFI I only wanted to do it once and I did want to get to MPFI eventually. Pete's heard my 'song' before but perhaps others haven't. EFI is afterall largely about producing power and efficiency by being able to deliver equal amounts of fuel to all cylinders which MPFI starts to accomplish. off my soapbox now.....PS my 'blower roll' at idle with my proflo is now greatly reduced that I richened up my superlean idle setting , felt kinda silly that I"ve solved that on carbs many times quickly (high idle/dieselling d/2 leanness) but skipped on the easiest of all to adjust lately, my EFI. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 20, 2001 Author Share Posted October 20, 2001 Ross, I agree that port injection is better, but the issue is by how much and does it really matter that much on the street. And thanks to a kind soul, I have a laptop and think I would prefer tuning/datalogging it that way. Heck, I'd probably keep the laptop in the car anyway, and build a mount for it! Good point though. For $500 more (both prices buying new retail), you could have port injection. I'd be giving up only laptop use, but would be probably quite fine with their control box. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 20, 2001 Author Share Posted October 20, 2001 Ok, a bit of a new twist on this old TBI vs TPI thread. To recap, I was asking if the Holley Projection 4DI would be a decent way to get something better than a carb, but not break the bank, while getting datalogging and ignition control. Well, Now Holley has revamped the Projection by using the Commander 950 computer and they've revamped the TB with new injectors and a progressive secondary throttle linkage. The one rated for 350-500 hp is described Here. So for a bit less than $1400 new, the complete bolt in system is looking interesting. I know I can piece together a port system and it would be "better" but is the extra gains with dry manifold and equal fuel delivery to each port really worth it for daily driving? It seems the upgrade from this system to TPI is $1000 more with the Holley 950 MPI system. Can another TPI system that can handle 450+ hp be put together for less than $2500 all parts included? This TBI system is looking enticing. $1400 I might be able to swing. $2400 is beyond reality for me. My current setup is a 750 vac sec either on a Holley 300-36 hirise dual plane or a Vic Jr. I would put this TBI system on the Vic Jr. Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted October 20, 2001 Share Posted October 20, 2001 Pete, my Edelbrock ProFlo EFI is good for 450hp and it costed $1925.00, it come complete with everything you need! Quote Link to comment Share on other sites More sharing options...
zgeezer Posted October 23, 2001 Share Posted October 23, 2001 It's a good piece, but stick with a DI version rather than the earlier one with pots to tune. Holley's earlier software is not as user friendly as one might hope. It almost requires a friend riding shotgun with a laptop to tune it. The newer software may be easier to use. Brother runs one on his 426CI Windsor/Falcon. Easy to install and it doesn't shout "FI" when the hood is popped. Great sneaker or off road piece. It runs well, better gas mileage (?), smoother than a well tuned double pumper, and it keeps that tune. Nice unit and they're really cheap on the used market. Real issue for me would be price and application. If you have a good intake manifold or wish to retain a "carb" look then this is a very good option. If you are buying all new parts (manifold etcetra) then I'd look at Holley's multipoint injection. zgeezer Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 23, 2001 Author Share Posted October 23, 2001 Thanks for that feedback. It seems there are 3 versions of Pro-jection: 1st: Analog, with pots for tuning (yuck) 2nd: Digital, 4Di computer 3rd: Digital, with Commander 950 computer. I'd probably only consider the last one. But the delta to go to an MPI system is "only" $1000. Maybe I'll just save a while longer for it? Quote Link to comment Share on other sites More sharing options...
Administrators SuperDan Posted October 23, 2001 Administrators Share Posted October 23, 2001 So far im really loving the Commander 950. Iv'e got my car dialed in now and it runs great. I spent a few days with the datalogger and it's damn near perfect now. Pete, if you come up with a mount for your portable id like to see a pic or some drawings, I need to make one for myself. Dan Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 2, 2001 Share Posted November 2, 2001 Okay, you guys need to check out a current Jeg's catalog. Accel now makes a EFI managment computer designed to control a Chevy TPI style system, or Accel's own variations on said system. It's called the Accel Electronic Fuel Managment System and what makes it unique is instead of a chip retaining the fuel map and such like the stock TPI would use, requiring a custom burned chip to change any values, this computer is fully adjustable using a laptop and Accel's CALMAP software. A direct user interface, and the benefits of MPFI, isn't that what you're looking for, Pete? Anyway, the computer weighs in at just over $900.00, add another $200.00 for the CALMAP software, what, 5 or $600.00 more for used TPI components from ebay, and you're aproaching the $1900 for the pro-flo system. You make the call, both options are out of MY price range. Just sending some more info your way. Ara Vahan Tucker Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 2, 2001 Author Share Posted November 2, 2001 Thanks, Ara Vahan, I'm still up in the air, but little bits of info like this help! I'm kind of lazy about big projects on the car at this point (lots to do to get it driveable) and I'm considering the Pro-jection right now as a bolt on and go system that's not horribly obscenely priced and should work alot better than a carb. But I'd sure like to have a Kinsler setup! Quote Link to comment Share on other sites More sharing options...
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