Can you explain how you came to this conclusion?

 

Roush LT- Yes I have read your thread and others on different forums also having problems with the warranty issue. The warranty is not a big deal to me as I stated earlier that I am already out of warranty on my truck. So I don't think it would do me much good. Maybe I am wrong here.

Huitt- How does the Roush come with a better intake??? I would be upgrading the intake on the Whipple to push higher boost, not that it doesn't come with one or that it is garbage. The pulley for the Whipple is about the same price as the Roush, so I don't see the difference here either. Bigger injectors also come with the Whipple, so again I see no difference. The Whipple does post numbers of added 160 hp increase, where as the Roush is at 145. So with the Whipple I am already starting with more HP before upgrading. The Whipple is also cheaper, but not much. Maybe I have misread something somewhere.

Yes the 12 PSI is pushing the limits on the internals, not the blocks from what I have read. I have also read that many are safely running 12 PSI on their daily drivers with no problems. Some are even at higher boost levels, but I don't won't to get too crazy here. I think the 12 PSI is plenty and will also go with a conservative tune so I don't make over 450 rwhp, if it is even that high. If after I talk to JDM some more and feel it is going to be problem I will back it down to 10 PSI. I would just rather get the work done now then have to upgrade down the road again when I want more power. Alot of guys pushing the 12 PSI said it was all in their tune that made the difference so this is what I am shooting for.

I went with the Whipple because after researching alot of others, Roush, Magnacharger, Kenne Bell, well you get the idea, the Whipple put out the most HP across the board and seemed to be the most effecient for what I am looking to do. I am not knocking the others, I just liked what I have read about the Whipple more. Maybe I am wrong here so don't get your blow torches out. Like I said earlier, I am no expert and am trying to learn here.

I appreciate the advice and think you all have some nice, fast trucks.

 

No blow torch from me.
I will say that some of your information and facts are not based on our trucks (04+ Supercharged F150's)

 

I have tried to sift thru all the information and weed out the other models and years. Search around, not just here, and you will find that some guys are pushing up to 15 psi on stock internals '04 and up F150's, not just the lighting guys or others on forged internals.
Why also would JDM say I could go no higher than 12 PSI safely??? I wouldn't think JDM would want to steer someone wrong and get negative feedback. I could be wrong here, and I still have to sit down with them and do some talking. Not saying that alot of guys are doing it, (12 PSI) just that it is possible.
Maybe someone could point out where this level of boost is a problem on our trucks??? I always like good reading.

 

12 psi will be fine as long as you don't abuse it. I've been north of 12#'s in my truck for almost 3 years without issue. It isn't boost that's the deciding factor...it's the tune. Have a good, safe tune and your engine will be happy for a good long time...can't say the same for your transmission and tires though.

 

Yeah, I know the tranny will go eventually but that is going to happen whether it is supercharged or not. Probably a little faster with the supercharger. I plan on beefing it up or replacing once its blown.
My tires will be fine as long as I don't light them up all the time. I am past the burn-out stage in my life. Roasted plenty of tires in burn-out boxes with my rice rockets, sometimes until explosion. Now I am just burnt-out.
Pretty much what JDM told me was that it was in the tune also. Safe tune=Safe truck

 

the rule ive heard to keep internal stuff safe is 8PSI but you have a lil. newer truck. hope it holds togther for ya ....i want a supercharger. dont think santa will drop one off thoe

 

The intake that JDM has been using is the Roush IC SC intake. It is the same intake that they upgrade the Saleen SC with. Unless you are going with a custom setup they did with Rafa26's truck which was a open element intake with a mustang twin blade throttle body.

The one thing that is really nice about the Roush is the use of a seperate belt drive instead of taping into the factory one. In this configuration you go with a larger lower pulley and not effect the power steering,waterpump,AC and alt speed. Changing upper pulleys is ok but generally the smaller you go the more belt slip you will induce.

You could due what Rafa did and incorporate the Roush FEAD assembly and have a longer snout ordered for the whipple.

Good luck on your choice either way you decide having a boosted truck is sweet. Oh and you may be past the tire frying days but you will find that it may creep back to you every now in then just to see the faces on the import guys as you smoke em!

 

x2 on this. I believe JDM is the only person offering that high of boost on the whipple and Saleen SC's. Once you beef up the lower end 15lbs baby

 

For the record most connecting rods fail in tension...something boost itself really does not have much effect on. People often attribute engine failure to the fact that the pistons are hypereutectic alloy or the rods are powder metal. Really, it isn't as much the material makeup of the engine as it is the tuning. JDM has a lot of experience with these engines and as long as they are giving you plenty of fuel there is no reason why 12 psi can't be sustainable.

 

So can we run 15 psi or even 18 psi with a safe tune if stock strength of material is not a factor?

 

My truck sees 13.8 - 14.4 psi in cool weather and a good belt. 15 psi wouldn't be much of an issue and has been done on these trucks. Also note I didn't say the materials were not a factor...just not as much an issue as the "12psi-will-blow-the-engine-up" crowd seems to think. I'm sure you could put 18 psi through a 5.4L with a cetrifugal, water/methanol injection, and a rock-solid tune...probably won't make too many passes at the track with it though.

 

I think we're talking about 2 different issues here. The tune keeping the combustion mixture in the cylinder from burning a hole through the piston and/or ring, and the rod being able to withstand the extra force exerted on it by the increased pressure in the cylinder.

 

Detonation is what the tune is handling. THAT is what kills pistons and rods. Very seldom will you find an engine that cratered simply due to too much cylinder pressure causing a compressive failure of the rods or pistons. Detonation doesn't just put holes in pistons...it causes a rapid, UNCONTROLLED combustion event. This is what hammers pistons and rods by greatly increasing combustion chamber pressure over a very short period of time. You can reach those pressure levels with just 6 psi and a bad tune...hell you don't even need boost really.

 

Good point on Detonation. With 5.4L 3V 9.8:1 compression, it would be very hard to control wouldn't it. Lower compression engines like the Lightning (8.X:1)would be easier.