ive been curious about this, i know how speed density works, i know how MAF works, but how well would speed density work with forced induction
fuel isnt as hard to control without MAF as you would think, there are so many things out there such as rising rate regulators, pinch valves, extra injectors, etc
an issue i was thinking, i know you need i think 15-17in/lbs of vacume, but to make power with forced induction, many times you need large throttle bodies, free flowing exhaust, and sometimes depending on the setup, a cam that isnt so hot for vacume, would that be possible to overcome?
im just talking out of my ass right now, im familiar with Dodges speed density system on the dodges, so i figured, why cant it be applied to ford?
http://www.powerdyne.com/upgradekits.htm
The Speed density calibration kit listed on the above site is nothing more than a one way check valve that is designed to Keep your MAP sensor from reading boost. Vortech sells one as well for about 25 bucks. Its the only extra you need to supercharge a speed density setup as far as centrifugals go. Upgrading throttle bodies and exhaust on speed density setups are not an issue. The biggest issue on the cam is lobe separation angle. 112 degrees is ok, but usually will run rough. 114 degrees seems to be the best bet. And as far as a Kenne Bell:
http://www.kennebell.net/pricelist/SC-PRICELIST.pdf
4th kit down on the 5.0 list is speed density specific.
do you have any specific cams that are known to be SD safe?
i did a little research and came up with some great info, but the thing that has me curious is injectors
if i were to do this, id definatly use a FMU or RRR (same thing, different name basically), but if i max out the 19# injectors, would i be able to say throw some 24# injectors in, and turn down the base pressure to keep it from running so rich?
The Kenne Bell Kit for speed density comes with an fmu and bigger pump. All the centrifugals come with FMU's some come with bigger pumps. In 5 weeks I'll be putting a Powerdyne 6 PSI setup on the Demon. 1600 plus the price of the check valve and tax will keep me under 1800. I SHOULD take about 8 tenths off a car that has run a 13.6. As far as cams go for speed density STAY AWAY FROM THE FORD MOTORSPORT CAMS! They are made specifically for mass air. Back in the day when they were the only thing around for a computer controlled 5.0 it gave people no choice but to do the mass air conversion. Nowadays there are a lot of SD came that are safe. Heck the stock HO cam aint bad for a blower. There are others as well. Crower part #15511 is an excellent speed density cam with the HO firing order. Crane makes some good ones as well.
Injectors: FPR and 24 pounders will work. I've heard of people using 30 pounders on an HO computer. Thats about the limit though. I've used 19's on an SO computer with an adjustable regulator. It passed NYS emissions and ran good. I would love to see if an SO could handle 24's if it had enough cam and head.
awesome man, i appreciate the info, youve answered everything i needed to know
not often that happend ;)
In fact: Check THIS out: 36#er's!http://www.50tech.com/forums/viewtopic.php?t=5027&highlight=stock+cam+differences+yeay
hmmm...more fuel...more boost...hmmm
also, im finding that quite a few guys over at turbomustangs.com run speed density, it appears that its easier to get a good baseline setup out of than MAF
off boost, itll drive just like it would bone stock, on boost is when you take the fuel into your own hands, most guys run FMU's and dont have many problems
theres a setup that stands out in my head for the power potential for cheap: stock block, E cam, mildly ported E7's, thicker headgasket and head shim for lower compression, equal length shorties flipped, 12psi on an intercooler, 440rwhp and 436rwtq, there are other minor odds and ends, but thats the general setup, im not aware of the turbo's that he used though
Or you could use a speed density set-up that makes use of a MAP that can sense boost and will adjust fuel accordingly ;) (<----future MegaSquirter...once I can get the time to get the friggen thing built :mad: )
Your Dodge turbo stuff was like that....
I'd thought about that. I'm unclear on what I would need though. Iv'e heard the terms like two bar and three bar MAP used on dodge message boards, but never got any clarification as to which would work well/be easier to set up. I'm just gonna hook up the check valve and FMU for my setup when it goes on next month and maybe if I get adventourous I will go the boost sensing MAP route.
2bar and 3bar represent how much boost they read in simple terms
i cant remember exactly which reads up to what, other than 3bar goes up to 29psi, people get really technical when explaining it, so im not completely sure how it works
to make that MAP setup work, it would take a lot of EEC work, because youd have to take a computer that never see's boost, and make it see and comprehend boost
1 bar = 14.7psi.
Atmosphere is 14.7psi...thus your std n/a MAP sensors are 1 bar.
2 bar = 25.4 psi absolute, or 14.7psi over atmospheric
3 bar= 44.1 psi absolute, or 25.4psi over atmospheric
IIRC the MAP sensor in my M-S kit is a 2.5 bar unit...or good to 22psi boost.
Like I said.......Check valve + FMU for me :D
hey Chuck, ive heard arguments that 2bar were 14.7psi, i forgot exactly what the argument was, but a few big guys at turbo dodges were saying that 1bar is really 0 vac and 0 psi, and 2bar was 14.7
any reason for them to think that?
Paul...thats the same route ill be going when i can make my project actually come together
Chuck's post is agreeing with the turbo dodge guys.
psig= psi gauge
psia= psi absolute
Psia is the absolute pressure, period. In space, the psia is 0. At sea level, psia is ~14.7.
Psig is the pressure relative to atmospheric pressure. At sea level, psig is 0 and psia is 14.7. At Denver, psig is 0 and psia is 12.1.
Let us say you inflate your tire with a tire gauge in Denver to 35 psi (47.1 psia), then drive to the coast. Your tire pressure (which is psig) will now read 32.4 psi, even though the absolute pressure is still 47.1 psi.
Make sense now?
Pau, are you sure you can run a Powerdyne Superchager on a speed density set up? I just got set up as a dealer for them, and asked about that specifically. They told me flat out " You have to convert to MAF to run our stuff" If you can run them with MAP, that would great to know, and pass on. I have everything for a HO MAP conversion for my Cougar, but was putting the swap on hold to go with MAF, just so I could run a supercharger (figured it would make good advertising....lol, and easier to get the wife to buy off on getting one...lol) Thanks for your help.
the thing is, you can run it with speed density, and use a fuel management unit, but the computer has no control over the fuel mixture under boost seeing as it doesnt realize theres boost
with a MAF setup, theres much more computer control over the injectors, since the MAF reads the air, and tells the computer to compensate for boost
Thanks TBird, I figured I would do the MAF conversion, better performance options down the road too. Still would be interesting to try it on a speed density system.
Didn't GM use speed density for a long time (or even still using it??) and have good luck with performance? Wonder why Ford switched out so soon rather than trying to dial in the MAP. It made more power stock than the MAF.. Although, why did/ does Ford do alot of the things they have???? Been a long time Ford fan, and always will be, but they still cease to amaze me with the changes.... Keeps you on yourr toes though, right....
Tbird is correct. With an FMU and one way check valve in the vaccum line to the MAP sensor you can run that Powerdyne with a Speed Density setup. Powerdyne calls the check valve and related hardware a "Speed Density Calibration Kit". The part # is H80265-003. Vortech makes their own version which they call a "MAP sensor check valve assembly", part # 4fd113-010. A word of advice....If you decide upon the 6 PSI kit as I have be forewarned it does not come with a bypass valve. I would highly recommend ordering it! In my searching the internet it seems the Problems with these kits stem from 2 things:
1) Overspinning the internal bearings by using an interbuttstuff pulley that is too small
(putting one in yourself to achieve say 13 PSI from a 9 PSI kit without upgrading the bearings)
2) Not using a bypass valve
A 6PSI or 9PSI kit will last a lot longer with the bypass valve. This ensures the backside of the impeller does not get boost kicked back into it thus shredding the internal belt. 9PSI kits have the bypass valve standard 6 PSI do not. Order it if you go with the 6.
Thank you Paul, you are wise beyond your years. I will keep the check valve in mind when I order and sell the 6 psi kits. I asked Powerdyne about the speed density calibration kit, and my sales guy said it won't work, you need MAF.... why sell it then? Looks liike I found the right message board, I think I will make it my second home....
I was browsing through corral.net last night, and noticed the same thing Paul mentioned, there are alot of guys trying to run more boost out of the powerdyne stuff without upgradeing, and frying the bearings and shredding belts. So what I have noticed is the BD11 Powerdyne is an awesome street duty, mild track application that proves to be fun, but don't over spin it. You want to go nuts, go for a procharger, but deal with oil leaks...
You can also put the Powerdyne XB series (gear driven) in the same brackets as the BD series, if I'm not mistaken. Paul, you probably know that better than I do, am I wrong, or right? Thanks again!!! You guys are great!!!!!!
Procharger, hands down in my opinion is the best blower. I've had a paxton
(Novi 1000) and two models of vortech ( S-trim & T-trim ) before I ended up with my D1-R and the unit crushes the other two.
:evilgrin: :evilgrin: :evilgrin:
BlownBirds, have you had a problem with the seals leaking oil? I heard that is a BIG problem with those....
My head unit has about 5,000 miles on it and hasn't leaked a drop. Now I have only had experience with the D- models (and 1 F-1R model in friends stang) but the outcome has all been the same. These blowers ( the big model D & F ) are not for the regular driver, so if the oil seal starts to leak its probably time for new bearings
(rebuilds run about $300 for bearings and seals). ( They won't sell you the parts)
What I mean for instance about not for the regular driver is my unit is rated for 30lbs of boost!
:evilgrin: :evilgrin: :evilgrin: