Boostec Supercharger Information

[CobraMarty]

Sorry, I had to look it up.

Definition of caveat emptor: Tacit warning to the buyers that the sellers are not bound to volunteer negative information about the items they are selling.

ca·ve·at emp·tor/ˈempˌtôr/


Noun:The principle that the buyer alone is responsible for checking the quality and suitability of goods before a purchase is made

 

[CobraMarty]

10*F change = 1% HP change.
That discharge temp doesn't reflect the effect of the 7th injector on cooling. A temp sensor on the intake and the one on the adapter below the TB and comparing would be interesting. The fuel will have a cooling effect. How much??

 

[O-Gauge Steamer]

I suspect absolutely none Marty, and Sprintex does not make any claim to that effect. The amount of fuel required to drop the discharge temperature would drown the engine. Much better off to inject a water/methanol mix. Something I will be looking at once I get the boost pressure up. Good thing it is easy to find, it is called "windshield washer fluid". Yup, look at the ingredients on your favourite bottle of fluid. Water, methanol and a dye... BTW, "Winter Mix" has a higher methanol concentration. When I get around to it, I will be putting in another set of injector bungs and injectors for the water/methanol mix along with yet another controller from AEM.

I like AEM. The hardware works as advertised and the software is user friendly. Even I can get it right.

Even at that, the discharge temperature of the compressor will not be dropped, the likelyhood of detonation is reduced so you can run more boost. The only practical way to cool the discharge is with an intercooler. There is no room in the Sprintex manifold for one. This system is just that. A system. By limiting the boost, an intercooler is not required.

Ford ran 5lbs of boost on the 79 Mustang Turbo Ghia. I know as I had one. Of course I did not leave the boost level there... But, that is another story.

Intercoolers are huge as there is a ton (this is not an actual value. Your results may vary. I am clarifying this before my detractors pop up and scream bloody murder) of BTUs to be transferred to atmosphere. There are two ways to go about it. Either way, you put a raditaor between the discharge port and the intake manifold. The variable is wheter you transfer the heat to water then to atmosphere via another radiator or you just run the discharge through the radiator and back to the intake.

Advantages and disadvatages to both methods. By directly cooling the discarge, you reduce the amount of hardware needed but you increase boost lag as the entire system will need to come up to pressure. By using the liquid cooling method, the lag is reduced to next to nothing. In either case, you are going to loose boost pressure and will require a larger compressor to compensate.

Again, Sprintex went with the extra injector format to contain costs and ease the installation. My concern with using the AEM F/IC over the Perfect Power SMT8-L is how often the injector will be firing. If I correctly understand it's operation, the SMT8-L fired the injector several times per revolution. Pretty much one inject per cylinder fire to give a consistant fuel increase. The F/IC6 will be injecting along with the number one cylinder.

I strongly suggest that you install a fresh set of plugs prior to the SC install and watch them closely for rear cylinder starvation.

It was this concern that drove me to install a new set of injectors. If you are wondering, a set of 34 pounders will work just fine. I chose 40 pounders as I had E85 in mind for down the road.

Due diligence is the word here. I can not say this enough. Urban-Yan is the perfect example of someone who did not perform due diligence and has been whining for, well years actually, about buying a used system that never actually had any sort of electronic controls and expecting support that also never existed. At that time (and today come to think of it) Mr. Rimmer was/is convinced that a rising rate fuel pressure regulator and an additional fuel fump was/is the way to go. This does not work on Fuel Injected engines. Does work on a blow through Carburetor equipped engine. Studebaker did it in the 50s.

But you still need to retard the spark under boost to prevent detonation and spark management is what you will get with the F/IC6. Some just dump more fuel in to stop the detonation. That works. Works at a cost. The cost being a loss of power. As any over-rich condition will reduce power generation. Mallory makes a distributor just for engines with Forced Injection. And, as long as it is either a Ford or Chevy engine you are good to go.

But I would take a good hard look at the ignition table once you install to make sure the spark is being left alone under non-boost conditions. Keep in mind that AEM uses Absolute Pressure and does not reference either "vacuum" or "boost".

Sorry about the Latin. It is a curse... Have to admit though, appropriate.

 

[CobraMarty]

Pulleys - crank=6.5 supercharger=2.5
Ratio 2.6:1 so at 5000rpm=13,000rpm for S/C max is 15,000

 

[CobraMarty]

Pulleys - crank=6.5 supercharger=2.5
Ratio 2.6:1 so at 5000rpm=13,000rpm for S/C max is 15,000

A 2.25 supercharger pulley would have a 2.89ratio and at 5000rpm=14,444rpm for the s/c and still under the 15,000 max. Still safe.

 

[gradon]

. . . but a bit over 15Krpms if you hit the stock 5300rpm rev limiter.

 

[CobraMarty]

I'm sure that the 15kmax rpm is not an absolute. 15,001 and it will not desinigrate. Even at 5300rpm and 15,317 s/c rpm, factor in a little belt slippage and I will take my chance on that, my trans shifts at 5k. Most manufactures have a conservative/low rating on their numbers and can be exceeded in most cases.

 

[merdock69]

Pardon my ignorance, but why can we not simply increase our injector size appropriately? Doesn't the ECM drop out of closed loop whenever under hard acceleration, decel, and WOT anyway? So with the larger injectors wouldn't it simply inadvertently provide more fuel based on the open loop mapping and during cruise would trim back to 14.7 afr? It seems that a piggy back controller simply adds fuel while the ecu is in open loop under acceleration and wot with the possible added benefit of retarding the timing. I'm getting ready to install a s/c in my '99 and could use all the help I can get.

 

[CobraMarty]

Not to sound rude or mean, but before you are anywhere near 'ready to install a supercharger', you have a lot of reading to do. There are many books on supercharging, and I posted some articles. Read all them, do your homework before you tackle this install or you will be very disappointed and have a bunch of parts that don't work or worse, a bunch of broken parts.

You are on the right track reading this thread, just read a bunch more.

 

[Talyn]

x2 real nice answer. Nothing but show for you.

Pardon my ignorance, but why can we not simply increase our injector size appropriately?

I know one or two people that have tried exactly that. They ended up with burnt pistons and tuliped exhaust valves.

The problem with that is the PCM can't see boost so it wouldn't know what to do with it. Even if you put a 2 bar MAP on it the stock programming still won't see the boost. It simply doesn't have the means to correctly meeter fuel under boost. Not only that but boost may come in prior before leaving closed loop, so you would be pushing boost and then the PCM would still be at 14.7:1 afr. Not good. In open loop the PCM will use closed loop fuel trim values to dial back the open loop a certain amount. At best you would be shooting blindly hopping that the PCM won't interfere when boost hits and hoping the correct amount of fuel is used.

You really need to do more research before you bolt on the sc.

 

[O-Gauge Steamer]

^^This is true. Due Diligenc is the operative in this or any other project undertaken.

It is an easy project, or it should be an easy project, as everything required is available "over the counter" so to speak. I ran into a detonation issue (after nearly a year of running the SC) as I had gotten too agressive with my ignition curve in pursuit of maximum performance. It has been dialed back and, once again, all is well. Detonations are in the "noise" level of the device I am utilising.

The Sprintex Kit, mechanically is well thought out and take little longer to install than just changing the manifold gasket. I have maintained this from the very beginning and as of now, I have installed 3 of them. More than anyone else on this board...

The only execption of the mechanical side is the bracket Sprintex provides to hold the cabling for the Throttle Body. It is too tall. It is as tall as it is due to Sprintex mounting the 2 Bar MAP Sensor in that location. And, whilst it makes little to no difference to an XJ, it buggered up the transmission shift points on the 93 YJ installation. The YJ uses a 727 transmission and relies heavily on the throttle valve cable. An AEM F/IC6 was used in this installtion as well and we were up and running by mid afternoon.

I base my decisions on extensive research and nearly 50 years of experience. My first SC installation was with my Dad and Older Brother. We added a Roots compressor to a '40 Ford back in '59... From there, I have nearly 2 dozen installations under my belt. Automotive, Marine and Motorcycle.

So, listen to whomever you wish, just ask for thier credentials...

 

[merdock69]

Got it. My intent is not to try just the injectors. I've actually ordered the same ss box that you're using cobramarty; I was simply asking for academic purposes.

 

[Talyn]

It has been dialed back and, once again, all is well. Detonations are in the "noise" level of the device I am utilising.

How is that knock detector working out for you? Do you know if it is getting any false positives?

The YJ uses a 727 transmission and relies heavily on the throttle valve cable.

Is that because the cable doesn't offer adjustment or because the angle of the cable?

How close was the YJ's calibration to the XJs?

 

[CobraMarty]

I know one or two people that have tried exactly that. They ended up with burnt pistons and tuliped exhaust valves.

The problem with that is the PCM can't see boost so it wouldn't know what to do with it. Even if you put a 2 bar MAP on it the stock programming still won't see the boost. It simply doesn't have the means to correctly meeter fuel under boost. Not only that but boost may come in prior before leaving closed loop, so you would be pushing boost and then the PCM would still be at 14.7:1 afr. Not good. In open loop the PCM will use closed loop fuel trim values to dial back the open loop a certain amount. At best you would be shooting blindly hopping that the PCM won't interfere when boost hits and hoping the correct amount of fuel is used.

You really need to do more research before you bolt on the sc.

I ran into a detonation issue (after nearly a year of running the SC) as I had gotten too agressive with my ignition curve in pursuit of maximum performance. It has been dialed back and, once again, all is well. Detonations are in the "noise" level of the device I am utilising.

The Sprintex Kit, mechanically is well thought out and take little longer to install than just changing the manifold gasket. I have maintained this from the very beginning and as of now, I have installed 3 of them. More than anyone else on this board...

I base my decisions on extensive research and nearly 50 years of experience. My first SC installation was with my Dad and Older Brother. We added a Roots compressor to a '40 Ford back in '59... From there, I have nearly 2 dozen installations under my belt. Automotive, Marine and Motorcycle.

So, listen to whomever you wish, just ask for thier credentials...

That's great, but you didn't answer his question, and you're supposed to be well read on the subject.... so please.... tell us why larger injectors, alone, won't work.

The ecu can see boost and the map sensor can see boost if the ecu is programmed to do so, at a cost of about $500, but then you have to have the maps made correctly. The stock map sensor can see boost but the ecu doesn't like the signal it sends it and will throw a CEL. The signal has to be clamped to prevent this CEL or the map sensor needs to be isolated from seeing boost. The map sensor does need to see near 0 vac for the ecu to go into open loop. If the map sensor only sees down to 2-3 inches vac, that is not WOT and might not go into open loop.

Don't get caught up with the hype and self proclaimed BS. As for credentials, ask the right questions- What is the IATemps, the charge air temps, Don't run 85 octane fuel, Don't use way too big injectors in anticapation of a future project, just to save $200, use the correct ones for the project at hand, Don't waste money on fancy gagits, $400+, when you run 85 octane fuel, open element air filters in the engine compartment and 200+ intake temps and wonder why you detonate and then stop it by just retarding the timing more. As far as 'persuit of maximum performance' and After 3 installs, where are the dyno sheets, what are the intake temps?

Larger injectors alone are not the answer. If that is the question, then one needs to read more. There has to be a total system approach. How is the fueling controlled, How is the timing controlled? Those are the questions, not just larger injectors.

Super or turbocharging today's computer controlled fuel injected engines is so very different than past engines with carbs and vacuum advanced distributors.

Now let's hear the rebuttals from the peanut gallery. Maybe this thread will get wiped clean/deleted like the others.

 

[bpas328xi]

Its nice to see you shitting on someone else that have given you help. All I see from you is bolt ons of numerous forms, no data aside from your all singing all dancing AIT, and no real knowledge shared. Get lost.

Dude. Calm down. It's just a car and just a supercharger.

FYI, I measured the supply voltage to the MAP sensor at 5.16 volts and under boost it will max out at that voltage.

"No real knowledge shared."

What do you want to know?

 

[CobraMarty]

Agree, this thread needs to be deleted like the others. TY.

 

[urban yan]

Why? So you can start another thread, and insult people like this BS never happened?
and, btw, this isn't your thread.



.

 

[CobraMarty]

Close and delete it because of the insulting and harassing posts like your's. Threads are not 'owned'.

 

[5-90]

I am going to attempt to get him to put the XJ on a dyno after the installation of the production kit. Drawing any conclusions from the prototype would be premature... Least ways, that's how I see it.

You can see what is looks like as well as get what information that is currently available at http://www.boostecus.com. You can also find Vids on Youtube...

If possible, you may find it useful to do a before-and-after dyno run (if you haven't started the install already...)

 

[kastein]

The ecu can see boost and the map sensor can see boost if the ecu is programmed to do so, at a cost of about $500, but then you have to have the maps made correctly. The stock map sensor can see boost but the ecu doesn't like the signal it sends it and will throw a CEL. The signal has to be clamped to prevent this CEL or the map sensor needs to be isolated from seeing boost.

The ECU "sees" a voltage from 0 to AVref, which is internally created by a regulator and fed to the sensors, in this case around 5V. How it interprets it is up to the firmware, which only sees 0 to about 1 bar (maybe a bit more) unless you completely reprogram it. I think you are saying that the "no mans land" between the normal minimum vacuum (around 1 bar, WOT) and AVref is "boost" when it's actually simply the ECU saying "the sensor is outputting more than we ever expect it to, a wire must have come loose."

Sure if you reprogram the ECU you can put a >1bar MAP on there and change the maps to compensate for the fact that max sensor output voltage is no longer equal to ~1 bar (for instance, with 5V AVref and a 2 bar sensor, 1 bar would be approx 2.5 volts), but that's not what most people are trying to do here.

You don't need multiple piggyback devices to get the job done, I'm sure you can set one up to handle all of it.

Super or turbocharging today's computer controlled fuel injected engines is so very different than past engines with carbs and vacuum advanced distributors.

REALLY?! THAT IS NEWS TO ME.

Now let's hear the rebuttals from the peanut gallery. Maybe this thread will get wiped clean/deleted like the others.

an attitude like this will get you nowhere and is only going to bring this "peanut gallery" (which seems to be more informed and better skilled technically than you) down on you... again. Stop poking the bees nest and then complaining about getting stung (errr, I mean claiming you were "insulted".)

I have said on multiple occasions that this handbag fight really needs to stop. All it is doing is annoying every single person watching it, and REALLY annoying every single person who gets an email every time you hit the report button and cry about it.

Please stop. Please keep the discussion technical.