several people have had concerns about rail pressure lately.there have been many posts about it,and ive seen many ask about how much pressure quads tow box adds.using a fluke,checking voltage at the sensor while driving,this is what i read.....1.6v at idle....2.5v to 3.5v regular driving ..........around 4v if your driving pretty hard......if you just stand on it,and let it really rev on out,it would touch 4.6v.......i had the max memory on,and i got one spike that read 4.8v...from what ive read on it,you will get spikes like this when getting out of the fuel quickly.anything over 4.6v ,the sensor is saturated and readings arent accurate according to the general concensus here.for those that dont have the conversion on it,that puts it at about 7k psi idle,14k to 21k psi regular driving,about 23k psi driving pretty hard,and if you really put it tothe mat and leave it there,about a 27kpsi max.....i would like to emphasise,to get it to 27k,you have to floor it,and leave it floored for several seconds straight............hope this helps anyone that was wondering about this box..................................bama

 

Hey bama I just got started this year on dtr, wanting to do stuff to my truck & all. As you can see by my sig. ihave the quad box std. on the way.I also am concerned about pressure.According to Quad himself via pm & some other folks around me who know more than I do the pressure thing is overrated,
overblown & overtalked. Like you say it doesn't show 27k until you just ram it to the floor & hold it awhile.nobody DRIVES like that unless you're in competition of some sort. Yes, we may drive like that for a few seconds but only for that amt of time. Quad says the vast majority of failures are in the racing community & says the stuff that will go out may have done it REGARDLESS,box or no box. The mechanics around me I know say unless you just drive like a bat from hell you'll probably be OK on all parameters(fuel,egt,
& boost) Towing will probably be the most critical area for most folks my self included

I'm gonna wait for the monitor to cone out for the quad box ao I'll be guageless for a while.I'm just gonna tread lightly on light or mid hp,use common sense,& I think I'll be fine.(There, I've convinced myself it'll all be OK!)

 

The factory sensor is pretty much done for at 26,000 PSI.

We use a transducer and gage set up. Very accurate to 50,000 PSI.

You would be surprised at the readings we see. 32,000 PSI from some of them. Advertised at no more than 26,000. LOL

Don~

 

Don, please expand a little more for the less knowledgable. the sensor does what? how is something advertised @ 27 jump over 20% to 32? Thats a little MUCH

 

The factory sensor in the rail is unreliable and not accurate in the high pressure ranges past stock. All transducers have a range they operate in and a specified accuracy for that range - given in percentages. Typcially a good transducer will run a 1% accuracy in the ranges we use ( 0-50,000 PSI ) This would cost in the neighborhood of 1 thousand dollars.

The factory sensor is not a lab quality part. Its accuracy begins to fade past 4.5 volts or 26,100 PSI. It is also done and finished reading anything past 29,000 PSI by design.

I have seen spikes of 33,000 PSI with the relief valve in place and 39,000 with it removed.

I have never seen much less tested a QUAD box, so I cant comment on that.

Don~

 

Thanks,Don! I am .0342% more smarter.

 

Don,
What's your take on the maximum safe hp gain that can achieved with pressure boxes while keeping it reliable?
BTW, when will your box be ready?

MikeyB

 

In the mid range, 55 or so HP is proven safe to me. I have been testing that since April of 04! No ill effects, broken injectors or accelerated wear. We drop the pressure back at higher voltage levels to control the pressure at high speeds, but this also drops the PEAK HP down to the 40 range. You just cant make more than 40 HP with pressure alone in upper RPM bands and have much of a safety factor left. I guess it depends on where the MAX power is made as to what is safe.

One type of box is done. Last minute tweaks on the power level switches are being made. The switch now is coded type rotary style, but I dont like it. Looking for something better.

Don~

 

as per dons statement,the factory sensor starts to fade past 4.5v...the quad box will not see that kind of voltage,unless you just hold it there for extended periods.with a truck as mine,with a 6 speed,the truck is already falling off and well past time to shift before this happens.the only time you could get it to go that high was when in 6th,matted for a pretty lengthy time..going by dons readings,the pressures were safe under nearly all circumstances.i think quad has made an excellent product with his box,keeping it safe,and it performs.all at what i consider a very reasonable price...............bama

 

You Da Man 'Bama, that's the kinda stuff I like to hear!!

I've been bombs away on this site, trying to make my decision. I'll read some good stuff then some bad stuff. What I'm getting out of this whole thing, seems to me for the most part that Quad has REALLY done some homework on this deal & put together the ultimate box. On other chips/boxes some say
the power comes in here or there, but with the quad they say its nice & smooth all the way thru!

Box oughta be here wed or thurs.

Now look guys,I'm pumped. I don't want to see anything else about................RAIL PRESSURE .....

 

Nothing wrong with pressure boxes as long it's a sane one. Like VA, Edge, Quad, etc.
I think Quad is getting around 50-55hp through pressure and the rest is via timing.
Oh, I forgot to mention the stock 600's run slighty more rail pressure than the 555.

MikeyB

 

I would love to try it when it's available. I have a used EZ on the way to try out. And from your recommendations it's staying at level 2.

MikeyB