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Ron, and xjr5006,
I definitely appreciate comments by both of you, because you each have far more hands-on experience in the performance arena than I will ever have, and, it's insight like this, that makes these forums such a great asset.
As I have said several times already, I'm probably not going to do this. I certainly won't be starting such a project this year, but, I DO have a very strong desire to do it...mostly, just because nobody else has done it yet. I also think that I can do it inexpensively (relatively), since I already have a spare HE with ported heads (needs at least one new piston anyways, due to an injector failure) and I have the pricey, programmable (and old) ECU. Even if I don't do it, discussions like this will help pave the way for for the next guy.
I've taken your advice to heart, and have done a quick Google search for tuners in the area, and will also ask some drag racer buddies if they have any recommendations. I also found out that Hesco (Hurley Engine Service Company) in Birmingham, Alabama is my nearest authorized Electromotive dealer. For anyone not familiar with that company, it is owned and operated by legendary engine builder Lee Hurley. He is also the guy who built Bradley Smith's twin Whipplecharged V12, complete with Electromotive TEC2 engine management. I believe he could definitely dial the car in. It seems that I need to make an appointment with Lee, and, schedule a trip to Birmingham in the somewhat near future. In the meantime, suggestions about how to go about basic engine modifications to handle the boost would be greatly appreciate(best & least expensive ways to lower the CR, ideal CR...I'm thinking 7-7.5, will I need stiffer valve springs to avoid valve float under boost, what size injectors, etc.).
...not that I'm going to build this
Zilla, without going into a lot ideas and opinions
fair enough, we on this site would love to see someone force feed a Jag V12, especially one with 2 supers, and 2 turbos
it would be a feat in engineering,to say the least ,and an encredible knowledge base of what works and what dont! (never mind the money).
your opinion on comp. ratio, some things to think about, low compression ratio, also make the turbos slow and laggy, the higher comp.ratio ,the quicker the spool and boost. exhaust port temps are higher with higher pressure, spins the wheel quicker!
some modern turbo engines are ratios up around 10-13=1, but using direct injection, quick think on D/I, is detonation control
port inj. engines mix fuel and air outside of the cylinder, so when piston comes up with F/A mixture it possible to combust before plug fires, instant explosion, hi/hi prssures, blows gaskets , rods,pistons ETC.
with D/I there is only air in cylinder so no fuel to fire early, fuel is injected at the precise time, into a small pocket in piston crown, then combustion comences, no detonation(maybe)!
most modern turbo cars have almost no lag, and if you check things out ,most mod turbos make torque way down low, and all the way to redline1
luckily we dont have to worry about emissions, like car companies do!
i think car companies use supers. for emission reasons.
and as you know HE heads were never designed for HP, they were all about emissions and MPG!
well the list goes on , where it is uncharted territory ",full speed ahead and damn the torpedoes"
things like valve springs and injectors, that is pretty much straight forward, you dont need much more spring pressure, maybe 10/20% over stock, and cams will have some bearing on the spring type.
(for a street engine, i like standard OEM cams, smooth, lotta torque, and rarely see redline,, if you aint won the race by then, go to plan B!, increase boost.)
also get some reading material about ,supercharging and fuel injection, again this is not realy new stuff, its just not been tried on a Jag V12, that guy that did a twin/charge, never was completly satisfied, with results, and rumor said he spent close to $75,000. or more trying, to beat BBC cars.
injectors; there are many injector charts out there , figure your HP goal , and order 12 (or 24) to closely match the numbers total!
your opinion on comp. ratio, some things to think about, low compression ratio, also make the turbos slow and laggy, the higher comp.ratio ,the quicker the spool and boost. exhaust port temps are higher with higher pressure, spins the wheel quicker!
Ron, I'm not worried about turbo lag with low CR. That's what the crank-driven superchargers are for in a twincharger setup. They handle the low RPM range, where the turbos are inefficient. As the RPMs rise, the positive displacement superchargers become less efficient, but, by then, the turbos are spooling up, and the bypass valve is closing off the airway to the SCs, and, routing all the incoming air through the turbos. The transition is seamless, and you get the benefits of massive low RPM torque generated by the SCs, and high RPM boost made possible by a very low CR and large turbos. All without turbo lag. My hope is that it would preserve the smooth, linear HP & torque curves of the stock V12, just at much higher levels.
again this is not realy new stuff, its just not been tried on a Jag V12, that guy that did a twin/charge, never was completly satisfied, with results, and rumor said he spent close to $75,000. or more trying, to beat BBC cars.
Actually, Bradley told me that he had a solid 6 figures in his XJS, although I never could pin him down to an exact number. He always said that he was afraid to go through the receipts, and, add it all up. He was able to raise or lower his HP by 50% just by swapping out pulleys. with 600-900 HP on tap (depending on pulley size), he had more than enough ammo for hunting Chevys.
I nearly bought his car a several years ago, but, I'm the kind of guy who would much rather build my own dream, than to buy someone else's.
Injectors,
I have a race set of real strange 4 nozzle black race injectors, crazy expensive and I am sure will deliver the claimed 1100 . Doubt I will ever use them and I certainly didn't pay for them; just part of a job lot.
My favourites are the early Pre HE green units, Flow much more than the later injectors and over here dirt cheap used. I simply send 15 off to get cleaned and then flow measured matching the best 12. Costs much more to get cleaned and measured than I buy them for. The jaguar service book says they should run at 31psi increased to 33 psi iof the customer complains about lack of performance. They seemed fine at 38psi on a standard ECU set up on a 7.3 engine.
Group 44 ran them at 60psi and having seen the spray must say its best at this pressure. The XJR5 uses these old injectors on the 6L 6.5L and 7L race engines, all at 60psi. Fueling is controlled by the ECU which determines how long a phase the injectors are open for. This in conjunction with the fuel pressure regulates how much fuel you get. I like to have an adjustable fuel regulator to fine tune fueling on a race engine from track to track. If I had a modern ECU I might do the same job without getting my hands dirty by massaging the injectors on a laptop.
Having said that if you are fitting a programmable ECU stick with the injectors you have and use the ECU to get the fueling correct. Cant see anyone else looking for more and more power at 8K and good fueling to 10K. So if I can manage it on std injectors so can you. I have many more things to spend £1000 + on than here I can assure you. .
Thanks xjr5006. You are on just such a higher level than any of the rest of us here, because, of the stable of vintage race cars you have, and, the standard to which you must maintain them.
I have the standard HE injectors. I'm not sure they would flow enough. If they would, I'd likely just have a set cleaned and flowed ($450 per dozen by S.D. Faircloth, last time I had them cleaned). Otherwise, I would probably look at a GM push-on style, in order to get rid of the rubber hoses to the tops of the injectors.
i use a custom injector that has push on o-ring top and bottom(just to get rid of the hose thing, with custom fuel rails i made of aluminum, and of course an adjustable FPR!
they flow about 20% more fuel than pre-HE injectors,at 30+ psi, and i'm at 45 psi at present,( very nice atomization on flow bench),with an adjustable ECU, i dial fuel flow back so as to make it idle and respond smoothly, and plenty in reserve when WOT, using an A/F ratio gage in cockpit.,along with lotsa tuning(thats an education in itself).LOL
they cost me ,new, $28. apiece back in 1995.
lets face it, some of us love this stuff as much as life itself!!
just a matter of time . AUDI just introduced ELECTRIC SUPERCHARGING, boost from idle onward,NO turbo lag! google lot of talk about it.
there engine has two sequential turbos also to overcome top end boost, electric from idle then, 1st a low/mid range turbo,electric when boost falls below a programmed point, then a top end boost turbo!! YIKES talk about a complicated system!
but supposedly it works well,to pass exhaust emissions, that VW has been working with also.
just more knowledge about forced induction engines,(JAGZILLA).
just when you think things have reached a peak something comes along with a better idea!
Electric superchargers and turbos have been around for several years (that is to say that I've heard, and read about them in magazines like Popular Science & Popular Mechanics for well over a decade). It was only a matter of time before an auto manufacturer put them into mass production. They are still parasitic, in that they gobble amperage, which, although I've forgotten the formula, requires a certain amount of horsepower to generate. As you stated, I'm sure makers have turned to electric superchargers for their emissions benefits.
Electric superchargers and turbos have been around for several years (that is to say that I've heard, and read about them in magazines like Popular Science & Popular Mechanics for well over a decade). It was only a matter of time before an auto manufacturer put them into mass production. They are still parasitic, in that they gobble amperage, which, although I've forgotten the formula, requires a certain amount of horsepower to generate. As you stated, I'm sure makers have turned to electric superchargers for their emissions benefits.
745.1Watts =1 BHP
W = E * I where E will be 14v
W/E = I so 53.22 amps / BHP best to use a higher voltage motor... and system...
Audi uses a 48volt system for the electric supercharger,and for other high volt stuff., a lithium-ion battery.
They also use a 12volt for running the vehicle and most 12volt stuff!
Like i said ,complicated system, but someone has to start somewhere.
And 1st theory's were around WW2 for an electric boost component for ICB engine.
Bendix had some mention , also Bendix introduced electronic fuel injection, in 1957 AMC cars, but they had the patents in the 1940s!
Bosch/VW liked it , so they bought rights for manufacture, today they are world leader in FI systems!
Guys, I really truly believe that electrically driven supercharging is not on, apart from, maybe, a very short 3 second or so burst. The energy equations do not remotely stack up. What does stack up, and will arrive once battery technology etc gets a decent, safe and reliable energy density, is electric motors that directly assist, if not replace any other sort of motor on the vehicle. far more efficient than driving a mechanical fan can ever be.
This is what Formula 1 is doing right now, and although the capacitors and storage media are extremely unreliable and dangerous, and voltages and amperages are sky high, it is being made to work. Not suitable for your local garage to work on though!
Greg
as Greg mentioned ,this electric stuff is getting dangerous.
passed by the elec.Mustang car shop , owner was laying down on sofa, he was working on,
electric system ,accidently ,touched BIG voltage/amperage, knocked him down to floor, helpers picked him up and put him on sofa, slowly trying to get heart rate controlled, and thoughts organizied.
side effect of not careful enough, and hurrying, with electric cars.
Hi regarding 500 bhp v12's. This is a profile I have for that, it wil fit in the std head With the springs,retainers and followers to match.And you need to grind a little bit aluminium to make the top of the lobe clear the edge of the lifter bore.
[QUOTE=Mobeck Tekniske;1498943]Hi regarding 500 bhp v12's. This is a profile I have for that, it wil fit in the std head With the springs,retainers and followers to match
Race setup for V12 Jaguar
Very interesting.
More information about this needed.
Prices, estimated time availability.
Are you reprofile STD shaft, or manufacturing new?
Maybe something else?
Hi regarding 500 bhp v12's. This is a profile I have for that, it wil fit in the std head With the springs,retainers and followers to match
Race setup for V12 Jaguar
Very interesting.
More information about this needed.
Prices, estimated time availability.
Are you reprofile STD shaft, or manufacturing new?
Maybe something else?
Yes ok. a pair of cams is 1580 euro.
They are not regrinds, new billets in steel. STD cams are cast, these are much stronger and gundrilled for lightness.
A regrind woud loose a lot of basediameter and you would not find space for a camlobe with this large area under the nose of a std cam. This is new blanks and therefor the cam has origninal basediameter and as much duration I want also on half lift.
They are made on order only and you must recon 5-6 weeks. Longer in spring.
I also have valves with 1mm larger head for std seats, they increase flow 15% without porting the runners, only a good seat job.
The followers are dlc coated and superlight. 26 euro a piece
Retainers are 10 euro a piece and double springs 15 euro. High quality race spring is 20 euro.
Let me konw if you need something as I am makeing a Batch right now. ole.martin@mobeck.com
Hi regarding 500 bhp v12's. This is a profile I have for that, it wil fit in the std head With the springs,retainers and followers to match.And you need to grind a little bit aluminium to make the top of the lobe clear the edge of the lifter bore.
02-14-2016, 12:02 PM
