I recently bought a 01 Cobra from another member on the forums here. I called my F150 tuner Mike from Troyer Performance and talked to him about the ATI Procharger P-1SC editions to which he said they are good little centri blowers but at about 12-13lbs their maxed out. Well the car has a built motor by Excessive Motorsports and was tuned by Jon Lund at the Evo Performance shop that makes 452rwhp with 14degree timing via a Mustang Dyno. I went on the ATI site and checked out some of the other peoples Cobra's and even GT's in the gallery section with that same blower and all but one seem to make about 50-100rwhp more on 93 than what I make. I was told Jon Lund likes to run 18degree timing and it would have made about 500rwhp but the guys on that site are running low Boost #'s like around 10 but I'm not sure if it's lbs or PSI, I will assume it's PSI and are making 500rwhp (so they say) with about the same mods as me. How far can these P-1SC chargers go safely? Here's a list of mods if that helps and can anyone explain the difference in PSI and LBS or how to convert it? I know how blowers and turbos work I even know about the BAR system used overseas but some people say lbs and some say psi when you talk about them. I have a roots style blower in my truck running 8.5psi but how many lbs is that?
Mods:
Exhaust:
Mac CatBack
Mac Catted H-Pipe
Mac LT headers 1 5/8
Built Engine:
42lb injectors
KB Boost-a-pump
Ported intake
Port & Polish
C&P Pistons .20 over
Eagle Rods
ARP Studs
ATI Procharger P1SC @ 12-13lbs (14 degree timing)
3 core A/A intercooler
Transmission:
Ford Racing 3.73 Gears
MGW Short Throw Shifter
Gotta remember your numbers are on a mustang dyno. Most guys who like to brag use dynojet numbers, your numbers are where they should be. Obviously you could get more running a razor's edge tune, don't see why you would want to though. From what I've seen the older P1's lay down around 14 psi on a stockish motor. Haven't seen the new P1's yet.
____________________________________
'01 Cobra-twin turbo, Art Carr 4R70W
'06 Trailblazer SS AWD-car seat and groceries
Last edited by rubber duck; 07-02-2009 at 09:29 PM.
lbs and psi are the same thing lol. psi is pounds per square inch, lbs is the same thing there is no conversion factor lol. besides that, you're running low timing and on a mustang dyno and they read lower.
____________________________________ 2000 BAB GT, Procharged, 4.10's, gears, exhaust, speedy dyno tune...Still a 2v though
368 hp
406 lb/ft on 7lbs
lbs and psi are the same thing lol. psi is pounds per square inch, lbs is the same thing there is no conversion factor lol. besides that, you're running low timing and on a mustang dyno and they read lower.
but 8lbs of boost doesn't equate to 8psi though, right? I know this is newbie but if a guy running 10psi is making 500rwhp and I'm running "12-13psi" but only making 452 that doesn't make sense. I know it's all about how much air is being pressurized but it doesn't make sense in my pea sized brain.
im prtty sure psi and LBS are the same.
pounds per square inch/ and lbs is just the shortened up version of that much like sayin thas a POS or a peice.
but 8lbs of boost doesn't equate to 8psi though, right? I know this is newbie but if a guy running 10psi is making 500rwhp and I'm running "12-13psi" but only making 452 that doesn't make sense. I know it's all about how much air is being pressurized but it doesn't make sense in my pea sized brain.
lbs=psi. it's just another way of saying it. this is almost too funny. if i were an asshole i would have given some weird conversion factor and you'd think you were running 212.64 lbs of boost or something.
timing, etc...can make a big difference. have you done a compression check to see what kind of condition your engine is in? perhaps it could be that. i wouldn't expect a whole lot more from 12 lbs than that on a 4v to be honest.
fwiw, you can expect since your dyno was a mustang dyno, it could be a little lower reading than a dynojet based on the way they put load on the car. if it runs fine, doesn't blow oil, and keeps up with cars with similar mods and more hp, then it's fine.
if you really wanna satisfy yourself, take it to a dynojet and run it on there, see what #'s she makes.
Is it possible that you don't know what the acronym "LBS" means?
"lbs" is shorthand for pounds.
Pounds is abbreviated lbs because the origin is in the Latin word libra, which could mean both balance scales (hence the symbol for the astrological sign Libra, which was named after a constellation that was thought to resemble scales) and also a pound weight, for which the full expression was libra pondo, the second word being the origin of our pound.
"psi" means "pounds per square inch." A unit of pressure.
So when someone says they run 10psi or 10lbs or ten pounds of boost, they are all the exact same expression.
However, this is all really not that relevant as the pulley on my blower will make ~14psi on a stock motor at sea level, and I'm only seeing about 8psi due to altitude and less restriction by having a full race exhaust w/ longtube headers.
So I'd say since you have exhaust and port work that the improved flow is lowering resistance. You're flowing just as much or more than the next guy but you don't see the resistance on your gauge.
I'd say your numbers seem right for the mustang dyno. You definitely need to step it up with the head unit. I may be selling my D1sc to upgrade to an F1.
____________________________________
97 Cobra, Procharger D1SC, 3-core race intercooler, 42lb injectors, Walbro 255lph fuel pump, Procharger big red race BOV, SCT 2600 MAF, Custom dyno tune, BBK Longtube headers, Bassani offroad x-pipe, Mac mufflers, Steeda Tri-ax shifter, Ford Racing 11" clutch, stock long block. HP: 502 TQ: 448
Last edited by SpittingCobra; 07-03-2009 at 03:40 AM.
Send the P1SC to procharger and pay to have it upgraded to the d1sc, only the impeller is different
____________________________________
DO NOT BUY FROM LIGHTNING MOTORS.1443 St. Georges Avenue, Roselle, NJ 07203 908-259-0022
They sold me a car that the motor blew up in less than 50 miles on the first night. Sued these bastards in court and won, still waiting on my money....
thanks for all the info and sorry for the newb question but yeah I knew it was lbs per square inch I'm just not sure why I was under the impression the two were different. I knew the basics but the lingo is still relatively new to me. It's a whole new world when forced induction is added and I'm not a mechanic or tuner by any means. I know what's in my truck cause I was there for everything but I'm still learning about the Cobra. Thanks again.
^^^Also you should take into consideration the compression ratio of your motor vs the compression of the other cars you were reffering to. If you have two cars with identical mods but one car has 9.85.1 compression and the other is running 8.5.1 and they are both running the same psi, timing etc, the car with the 9.85.1 compression should make more power.
Sounds like I need to take it somewhere around here so they can determine the compression ratio. I wouldn't mind upgrading but I would have to take it to my tuner who is about 5hrs away to have it re-tuned, I haven't heard any good things about the guys in my area such as DTP racing. I'm not in a hurry really I was just curious and since 452rwhp isn't bad by any means not to mention it sounds like I would be pushing the P1SC to it limits if I were to add another 4 degrees of timing. Thanks again
Sounds like I need to take it somewhere around here so they can determine the compression ratio. I wouldn't mind upgrading but I would have to take it to my tuner who is about 5hrs away to have it re-tuned, I haven't heard any good things about the guys in my area such as DTP racing. I'm not in a hurry really I was just curious and since 452rwhp isn't bad by any means not to mention it sounds like I would be pushing the P1SC to it limits if I were to add another 4 degrees of timing. Thanks again
Adding timing doesn't push the blower harder it pushes your rotating assembly harder. The only thing that will push the blower harder is by increasing the blower rpm speed ie getting a smaller pulley and increasing the boost. As for your compression ratio, what kind of pistons are in your motor? Knowing that will give you a good idea of your compression. And +1 on upgrading to a D1SC. The D1SC can take you to 600 rwhp easily. More than that look to go F1.
C&P Pistons .20 over. I've never had a built motor so a lot of this stuff is new to me but I'm trying. Yeah I don't think I would go over 600rwhp but I do wonder how much power my motor can handle. I also wonder about the 3650 trans and how much it can support, I have a centerforce clutch which is pretty nice. Like I said I'm still learning about the Cobra and it's DOHC 4.6l. I know all kinds of stuff from trans to motor on 4.2L and 5.4L via F150's but this car is still a mystery.
^^^Its cool none of us know everything. I learn new stuff from this site everyday. Just found out I can use my stock timing cover if I wanted to switch to C heads.
If you have documentation on your engine build you could find it there. Or if you know the person who had the car before you ask them. Either way 450 rwhp on a mustang dyno is good considering your mods. If you had it dynoed on a dyno jet you might see 500 rwhp but thats just how the different dyno's read, not that you would actually be any faster.
An Anderson power pipe would help a little. I had a p1sc with a 10% crank pulley. I was seeing 12 psi and i had 456 rwhp so you're not that far off. I'm also stroked to 298 ci. i upgraded to a D1 and I'm now at 544rwhp on a safe tune
yeah the previous owner on here meant it to be conservative which I'm fine with so I guess I can't complain I was just curious to what that P1SC could do.
As one of you pointed out, the D1SC is a better unit, with steeper internal gearing and an upgraded impeller. Thereby, making more boost more efficiently than a P1 without having to go to a smaller pulley.
But the biggest limitation with the P1 (and even the D1) is with the belt setup. They run off the factory 6 rib serpentine belt. This creates inconsistent boost during heavy fluctuations in RPM, and increases the risk of throwing belts.
I've had my P1SC making upwards of 15-16 PSI. However, I've made 510RWHP on only 10PSI with a powerpipe and exhaust.
The P1SC will support upwards of 500 HP if the motor is tuned correctly and no bottlenecks are present (powerpipe, good exhaust, good tune, etc). You can easily increase this by going with an 8-RIB conversion (which should be done regardless).
The D1 is an impressive little upgrade. My friend Brian with a Red 01 cobra (who resides on these boards) installed a D1 head unit on a nearly identical engine combination as mine made 569 WHP on 12LBS of boost (when I made 510 on 10LBS of boost). Both engines had stock internals at the time.
While I'm happy with my P1 combination because I have stock aviator internals with 10.5:1 compression, and don't plan on pushing any more boost. Since you already have the P1 head unit, there are a few things you can do before you get something else.
1: Power Pipe (this will give you a few extra LBS of booost)
2. Blower-Brace (reduces belt slip and flex)
3. 8-Rib Conversion (or even a dedicated conversion). Since the blower case is the same size as the larger D1 or F1, you can upgrade the bracketry now and see how much of an improvement you get. There was a neat article in 5.0 mustang about a dedicated blower belt drive that significantly increased horsepower with the same blower and pulley sizes.
4. Once you have addressed the aforementioned supporting issues, only then would I upgrade the head unit. You could upgrade the impeller to D1 status for $1200, but you might as well just go balls to the wall with an F1 if you have the supporting mods.
^^^House of Boost make a dedicated drive for 2 valves and has a 4 valve kit on the way. I keep hearing and reading good things about their 2 valve drive so I'm eager to see the 4 valve.
Very neat!! I think that may be the solution before making any other drastic upgrades. That way, you can extract every bit of capability from the P1SC first.
If you upgrade to a more capable blower first, you'll still have the same issues limiting the potential of the new blower.
In the article in "5.0 Mustang", the increase in boost and power from upgrading to a more capable drive system was so drastic that they had to retune the car. And they didn't even change the pulley diameters to run more boost.
Linear Mode
