Holley 900 CFM 4Di injection question.
 

How well will this work? I can get it for $800. Sounds like a killer deal but I wanted to know what you all think. I was gonna go with a carb but FI seems easier and I really need a good reason to buy a laptop, and if I get this I'll need one. I'm looking at getting the AlienWare Area 51M laptop. Most sweet.

Thanks.

Brad...

From the owner:

900cfm. Supports 350-500Hp. It bolts staight on to any square bore manifold, such as the Performer RPM. It has the entire wiring harness and the ECM. You can program anything and everything you want with a computer. Software is included that you load on your computer. It's a 4-wire hookup and it's running. The most challenging part is installing the fuel pump and filters. Pretty easy system. I had it going in 1 afternoon the first time I tried.

I have seen it work poorly on some normally asperate vehicles and very well on some roots blown vehicles, go figure...

.

Considering you can get it BRAND NEW with EVERYTHING for only
$1260 from Summit (10% off till Dec. 31)....

Also keep in mind it will only support about 525 horsepower MAX. with a BSFC of .55 - .6 (slightly rich for boost) and holleys BIGGEST low impedance injector (85 pph) and roughly 85-90% Duty cycle on the injectors (highest safest for full control) you will see you only have enough juice for about 530 horses.

I have this setup, and it works nicelly with a roots blower.
Dont give up though, EFI is the way to go for power and fuel economy. you should look into multi point setups, the cheaper ones like the holleys tealth ram KIT (everything you need) for $2K (perfect for twin turbo setup) or even a do-it-yourself kit, which you can weld your injectors into whatever manifold you want then just throw a throttle body on it.

Using holley's software / ECU to control it is great too. it has boost compensation, timing control, Hell goto holley's site and look it up you will see what they offer. the tuning manual is 92 pages long, and goes over only 50% of whats actually IN the ECU itself. took me about 2 weeks to get my car running "right" with the DFI, and it will take me longer to get it running "perfect". the hardest parts are in the open loop conpensations, where %'s and timing roles cannot be calculated by the ecu, but rather have to be inputed. oh its a jolley good way to spend a few afternoons!

Also look here:
https://www.thirdgen.org/techbb2/sho...hreadid=144692

and here:
http://www.holley.com/HiOctn/ProdLin...B/950-21S.html

and here:
http://www.holley.com/HiOctn/ProdLin...PFI/MPFIS.html


that should get you started! email me for more info.

.

well is it the 21S system with the 85 PPH injectors?

and your including EVERYTHING? fuel pump? ecu, harness, etc...

and its the digital setup with the software (included) for a laptop? and the progressive linkage type throttle body?

when did you order it? why are you selling?

heh sorry for the questions but if Bhass doesnt buy it I WILL if you satisfy these questions. let me know! of course, he has first dibs on it... but otherwise... I will take it for that price. instantly.

.

.

good for you I like to see that attention to detail, instead of miles of rubber hose running all over:)

I've decided to go with the carb for now. So if Kingtal0n still wants it go ahead and sell it to him. I was thinking if it's only good to 500 hp and somehow I make more with the turbos it would go lean and that wouldn't be good. Thanks QwkTrip for the fast replies on that. Wish I could use it. I think FI would be fun to play with. Maybe some day.

Brad...

500 HP not with an FMU....

Tom, I know that you like FMU's but the idea of switching to an aftermarket ecm and still running an FMU is just retarded...

bhaas, you may want to recheck the available injector sizes for it, since I seem to remember that no matter what they say, they've got injectors that would feed up to about 700hp without even upping the pressure (of course that's actually assuming that you use some sort of forced injection to get enough air through it), which to me looks a lot like you should be able to feed substantially more with some fuel pressure tweaking (it's up to you if that's worth it long term)

normally retarded yes but we are talking about a holley projection right? I guess unless it is run by the new commander 950 controller as some are.

.

.

<b>holley projection right?</b>
Right Quik has the Projection setup which is very very different from the commander 950 setup.
the projection setup is all analog and requires an idle vacuum of at least 15-18" (in gear for auto) and its only good for slightly modified engines, and does not have boost compensation. it does not require a laptop since the controls are analog and done by hand.

The commander 950 is the NEW setup, its called "Holley DFI Commander 950 Throttle Body Injection..." Yadaa yadaa yadaa...

it is a digital speed density setup that requires the use of a laptop and has multiple fuel / spark maps and controllable timing and boost compensation.. blah blah blah... this is the setup I need an extra one of, and its $1399 brand new. This is the setup I was referring to. If this was the setup Quik had available, I would buy it for his asking price.

.

okay i was wrong. i wasnt aware they had a separate programmable thingy without the C950 interface. Dis-regard my comments.

Kingtalon your idea could still work. If the "middle" system he has (not C950 - not analog) can be adjusted for boost then its still a possibility. Otherwise the FMU idea might still work too.

The holley TBI setup is not a bad one, I used their 700cfm 4bbl on my car for a while.

This is what I understand the problem of using the holley system with a blow through setup.... its because the injectors cant stand the higher pressures required. This is because you always have to maintain pressure differential to maintain consistant fuel flow.

What I mean by this is that the holley setup will support that 500ish hp in naturally asperated form at a fuel pressure of 15-18 psi... but you cant increase the pressure beyond that so if you were to run 10 psi of boost to keep the injector flow the SAME you would have to run 25-28 psi of fuel pressure. Since you cant increase the pressure you are essentally running 5-8 psi of fuel pressure and therefore the unit would support drasticly less power. This is because the holley setup was never ment to be behind a turbo setup / or vortec/procharger style. Sure it will work fine under a roots blower.

.

.

.

<b>The fuel pressure gauge might read 40 psi but that's relative to outside atmosphere air pressure. </b>

I think your wrong. 40 PSI of fuel pressure at sea level is 40 PSI at anywhere else.
its the air-density thats affected by altitude and atmospheric pressure, not the fuel density. boiling point is affected in fuel because of less atmospheric pressure. the same way it affects water. but not the actual density of the fuel. 1 gallon of fuel is 1 gallon of fuel at any altitude. 1 gallon of air is 1 gallon of air at any altitude. the density of the air, however, changes with atmospheric pressure. the fuel's density, does not.
if the fuel density was affected then we wouldnt have to jet our carbeurators leaner when we went to higher altitudes.

An FMU can work on a TBI setup to an extent... if you have too much fuel pressure it will cause the injectors to lose control over fuel flow. this is not uncommon in low-impedance fuel injectors. high-impedance injectors can support up to over 120 PSI because the injectors are made to control a smaller amount of fuel, with more pressure to promote good atomazation and spray pattern. I think the pressure cap for most bottom fed injectors (TBI low-impedance) is like 30 PSI. Holley recommends a max of 24 PSI however. but dont quote me on that, their website says different stuff than their tuning manual.

I’m not really sure what you’re getting at, but what is at issue is the pressure across the injector. If there is 10psi fuel pressure and you’ve got 10psi boost, then there will be no relative pressure across the injector and no fuel will flow. If you have 20psi with 10psi boost you will have a relative pressure of 10psi, and the flow will be the same as 10psi sprayed with no boost.

.

QwkTrip, I was commenting on Kingtal0n's last post

.

Well, as far as I can tell, the 2 of us are on the same page...

.

<b>If there is 10psi fuel pressure and you’ve got 10psi boost</b>

you THINK your on the same page, but your not. The throttle body of the TBI system houses the injectors, not the intake manifold. therefore the injectors never see the boost, in fact all they ever see is vacuum. I was referring to a roots blower application, not a blow-through. this is why the TBI setup is "made" for roots blowers, you dont want to (dont have to) use an FMU to maintain proper fuel pressure. Raising the fuel pressure of the low-inpedance injectors to match blow-through boost levels can have bad results. quoth the holley.

This thread was started with bhaas talking about using this setup on his twin turbo, which just about has to be blow through. That is what I based my answers on.

And I'll say it again. FMU's can work, but if I'm going to send the money/time on aftermarket injection I sure wouldn't be planning on getting something that I would still have to run an FMU with.

<b>That is what I based my answers on.
</b>

Crossfire, as usuall, your totally correct. I didnt specify exactly to what I was referring. My initial comment was on fuel density. I just wanted to ask/clarify quik's statement:

<b>The fuel pressure gauge might read 40 psi but that's relative to outside atmosphere air pressure.</b>

and HE was totally correct because HE was mentioning:

<b>The only thing that matters is the pressure drop across the injector is 15 psi. </b>

which pertains to the same thing YOU were mentioning and I totally FORGOT about the fact BOTH of you were referring to BLOW-Through applications so I was totally WRONG to say what I said. I need to learn to keep my mouth shut (fingers still) when I get to this board. My mind keeps associating things with the incorrect things and so on. Ooops. Sorry. :( Ill try not to do it again, although my ability to read and process information isnt always that good at 3:00 AM, i still try :)
... make that 4 AM.

.

yeah i did that, then i sold it. then i went with my father's project and did a weiand 177 with the holley dfi C950... that was a great success. now im looking to make MY car fuel injected, but cant decide whether i want a roots/throttle body type setup or a stealthram/tpi type setup. the roots setup would make more power but would get worse fuel economy and stick out of the hood. the stealth ram would give me decent drivability and better fuel economy, and it would fit under my stock hood. (huge plus where i live). it would also allow me to use a cntrifugal later on... but WAY later... they are so expensive! for the cost of a centrifugal supercharger i could re-vamp my car's entire drivetrain.

Kingtal0n, you've probably seen it, but this is the M90 eaton setup that we put on my brother's car last winter:
http://home.att.net/~ampikas/Engine040202a.jpg

He picked up the blower with all the ducting, intercooler... for the same price as he sold the ducting and intercooler (less then $200 anyway).

I've been measuring out the engine bay in an f-body and there appears to be more then enough room to do that with a TPI, there even appears to be room to fit an M112 (same thing that comes on the Cobra's and the Lingenfelter 'vette package) like that.

What would be truly badass would be to use the bottom half of something like the stealth ram and adapt it to hold an M90 or M112 right on top, should be room with some patience and motivation.

I sort of remember somthing like that... very impressive.

wouldnt a centrifugal sort of setup be more... efficient in the long run though? the eaton, i beleive, is a screw type right? the boost is made IN the blower, like a centrifugal, as opposed to on the OUTSIDE, like a roots. Ive never actually seen one up real close on the inside. That IS what it is, right?

Arnt centrifugals still better? I've little experience with them, and none with screw type. how much hotter does it get the air than a centrifugal? how much boost are they capable of... like the one in the picture? sounds like a hella job. really nice.

This is very funny Because I ended up using an analog projection TBI controller to drive eight 24# SVO's on a "force" brand fuel injection setup on the JYD when I still owned it. It ran Great! Before I built the harness and started putting around with it I told the Holley guys about it, they wanted to know everything. How it worked out, what I did, how it ran, where I got my hardware. Well they were of some small help to me (they got me some harness parts) and little did I know, WHAM! a year and a half later they had the almost identical system out with the exception it was controlled by their new (at the time) controller the C950. When I say identical, I mean it. the only thing different on their hardware was the injectors.:rolleyes:I got the controller in a trade and said hey what the heck and made it work. the 19#'s are whats pictured but it got the 24#'s about 5 minutes after I started it and found I had to put the adjustment knobs all the way over to get any power out of it. It idled beautifully and dynoed with the W/B O2 in the 14's at idle in the 13's at cruise and in the 12's under power. it made around 435 RWhp and well over 500 ft# on a 150 (5151 jetting). It ran 11.90's @ 117 on the nitrous. (Video)

Hum, let me put it this way, what does all the divisions of GM, Ford, Jag, Austin Martin… use as an OEM blower? All of them have to deal with CAFE fuel efficiency standards and other federal regulations, do you think that they’re going to use something necessarily inefficient?

Eaton blowers have roughly 90% volumetric efficiencies (pull them apart and port and polish the inlet/outlet it could be brought up to 95%, the newer epoxy coated rotors also help), and have adiabatic efficiencies in the low end of most turbo compressors. This is much better then a centrifugal with better durability (doesn’t need to turn the high rpm’s so there’s no cranky transmission), and you get boost everywhere (my brother’s car’s torque curve is pretty much flat through the whole range that the dyno was able to measure).

No, it works exactly like a traditional roots blower with lobed rotors (actually a tuning hassle under boost, when you start dataloging you find that you get boost in pulses and you’ll have 1 frame where you’ve got 10psi, and the next will have 2…), but the rotors are cut helically to get better efficiency, which causes people to mistake them for screw blowers. Whipples/screw blowers are usually very nice though…

You’ve said this before and I was going to say something but didn’t. You’ve got this ‘traditional’ definition backwards. As per this definition, positive displacement blowers compress air inside the case, centrifugal do not, all they do is accelerate it creating a dynamic pressure (sorta like the force of wind hitting an object) which is converted to a static pressure (psi) by the diffuser, outlet and restriction of the engine.

In reality, nothing that I know of that we use as a superchager on the street actually acts as a positive displacement compressor (building boost inside the case). In all cases what actually happens is that all it does is accelerate the air and you get boost from the restriction of blowing into the engine.

Better in what way? Yea, they might have marginally better adiabatic efficiency, but not much (not sure, I’ve never actually seen a published compressor map for a centrifugal blower, I suspect that most are more inefficient then you expect since none of the designers want to talk about it at all). One really nice thing about positive displacement compressors over centrifugal compressors is that there is on surge line, it really doesn’t care what it’s blowing blowing into. If you put too big a centrifugal compressor on too small and engine you end up in surge, which is roughly where the compressor cannot pump as little air as the engine will take and you get weird pulses through the thing which can eventually hurt the compressor (especially noticeable on turbos, which are terrible to drive at surge)

Centrifugals are preferred in some street tire classes since they pretty much suck at lower rpms, making no boost and making the car easier to hook (before some centrifugal guy jumps down my throat, do you have boost and a torque peak below 2000rpm on an engine that makes power up to over a 6K redline?)

How much boost are they capable of? Well, that depends on what they’re blowing into, the more restrictive the more boost. They do have a physical limitation in that they are designed for lower boost levels and the faster you spin the rotors and the hotter you let them get, the closer you come to their design limits (they’re aluminum so they expand and at some point there won’t be enough clearance between them). Eaton only supplies it’s compressor maps with information up to 10psi/12,000rpm, and Eaton engineers won’t say anything about them past 15,000rpm. I know for a fact that they actually continue to get more efficient past that. My brother is spinning his M90 to about 18,000rpm at redline with about 10psi boost. Mike S used 2 M90’s on his 351 ford to make OVER 16psi (I believe that he was using a 15psi gauge and a 2 bar map so he doesn’t know how much…). I would guess that the older, non coated rotors would be more tolerant of higher boost since they have larger clearances…


I’ve said this about a lot of things before, nothing is best in all applications, but there are always advantages going one way or another.

Im surprised a lot more people arent jumping on these eatons, they are very cheap and there are many types available there under the search word "supercharger" if there is no damage to the lobes and it turns free chances are it was simply pulled off a wrecked car by these savy Junk yard scroungers and sold there on Ebay for projects. I see mercedes, Jag, GM BOP, and Ford (lightning/harley) there commonly.

.

Well, that M90 has proven reliable into the 500chp/11second/low120mph range an has been on 3 or 4 3-400mile road trips, 2x it was driven, raced all day and then driven home...

I hate conventional wisdom. Yea, it's a small blower, but it does work if spun hard enough. In a perfect world the car would probalby have an M112, but there isn't enough room under the hood without major changes and they cost 10x as much (still 1/3 of what a similar sized centrifugal...)

yeah but for the dirt price you could "take two"?

.

If I came by 2 for dirt cheap they would be on my truck within a week...

<b>well is it the 21S system with the 85 PPH injectors?

and your including EVERYTHING? fuel pump? ecu, harness, etc...

and its the digital setup with the software (included) for a laptop? and the progressive linkage type throttle body?
</b>

you already said its not the commander 950 ECM. that means its also the older style throttle body, without progressive linkage, according to holley. I need another one but it has to be commander 950 because I've already got fuel and spark maps i want to Xfer over, and I need the C950 to do it.

.

heres one http://cgi.ebay.com/ebaymotors/ws/eB...tem=1874780631 and heres another http://cgi.ebay.com/ebaymotors/ws/eB...tem=1874997742