buy my 5.3 so i can buy a 6.0

 

The 500rwhp was on pump gas? What ever happened to 116 octane fuel?

 

Fun time at the dyno today. It took longer than I thought it would, I need to work out a special deal with those guys some how.

We logged with the mega viewer and efilive on every run, we tried to keep everything all organized but it is still kind of confusing sorting thru the data. I had a plan but we ran into problems and it kind of all fell apart. I learned a lot today.

First run was right off the street, closed exhaust, pump gas, controller on low, 8psi. 388rwhp 407rwtq.

Next run we opened the exhaust, boost went up to 8.5psi. 403rwhp 418rwtq.

Next run we turned up the boost a little, logger shows 10psi. 428rhwp 445rwtq.




So far so good, everything as planed. On that last pump gas run we got just a touch of knock so we decided to step up to the race fuel, we completely drained out the 92 octane and put in 15 gallons of 118octane. The plan was to make a run with just the race fuel in there to see how much it hurt power. We started a run and got huge KR right as I was hitting it. Like 8deg right off the bat. Someone suggested maybe the timing was too low for the slower burning fuel and I didn’t know what else to try so we skiped that test and added some timing, bumped it to 22deg.

We try it again, our set up now is 10psi, open, race fuel, 22deg. Once again we got huge knock as we rolled into it. Not sure what to do we decide to toss in the cold plugs. I was running tr6 plugs up to this point, switched them out to br7 plugs.

We try it again, HUGE knock still under 2500 as I try to roll into it. I think the locked converter combined with a loaded dyno puts way more of a load on the motor at those lower rpms then we would see in the real world. I was lazy with my timing programming and just set the entire lower part of the table at 22deg. If we had time to play with it ramping up the timing might have fixed it. On the way home I hit it a few times and didn’t see any knock at all.

This is a good place to mention the drastic VE changes when we put in the good gas too. The idle a/f ratios went from 14.x up to 19.x just by dumping in the race fuel. that’s pretty huge. We were adding fuel all over to make up for it. The WOT fueling is easy to get right but the part throttle is harder, a lot more cells to adjust. We kept the a/f ratio under 12-1, sometimes as low as 11.3-1.

We finally decided to just avoid the knock by rolling into the throttle. All runs from here out I just rolled into it till 3000rpm then floored it. We stayed out of knock entirely doing this. If your compare these runs to previous runs or to other turbo systems like the sts it would be good to remember that I had to roll into it.

We did get some partial numbers on the above runs while playing around and surprisingly they were all around 430rwhp. We did a full pull at 10psi with the race fuel, 22deg, open ex and the numbers were nearly identical to the pump gas, 17deg runs. I didn’t post any of these runs since they all looked just like the pump gas run.

I gave the controller a little bump and the boost jumped to 12.5psi, that got us to 455rwhp 473rwtq. No knock rolling into it.

I bumped it again and got to 15.5psi and at this point we got 480rwhp 511rwtq. I didn’t post this one up. At this point the controller was at 40, we started at 10 and that was 8psi. Every bump on the controller moved the boost up nicely. Next run I put it at 50, then 60, then 70, then 80, then 100. 100 is as high as it goes.

With the controller at any number from 70-100 the most boost we could get was 18psi. Best numbers at 18psi were 494rwhp 540rwtq. I actually saw over 500 on the screen but the mustang software smoothes the **** out of the curves and it knocked the 50x down to 494.

We had a lot of troubles keeping my lap top running, I think my pcmcia-serial adapter has a loose connection. At about 17psi we popped off the intake piping. Mike the shop owner rolled the edges of the tube that popped off so the clamp had something to grab. We could hear it missing above 5500rpm and couldn’t get any more boost. I don’t know if the valve float was keeping the boost from going up or if it needs a heavier waste gate spring. Once I got on the road and hit the gas it floated the valves soo bad it wouldn’t even shift and I have my shift points at 5800. I turned the boost all the way back down to 14psi and it is still floating the valves badly but it will still pull hard enough to get to the shift point at least. On stock springs something less than 14psi is max it seems.



Where does this leave us? Based on previous trips to this dyno it seems the 4.8 is down about 40rwhp from the camed 6.0 at 10psi. That is pretty impressive. Valve springs would have helped at higher settings but I don’t think they were hurting me at 10psi. Here is a chart I did up on the 6.0 a long time ago. Same dyno.

 

after looking at that 540tq graph i am 99% sure some good springs would have produced impresive hp numbers. that tq droped prety fast.

dyno runs on a mustang dyno are kind of scarry they last sooo long and the whole time i am waiting for it to blow up. it was spooking and fun at the same time.

kyle is going to make up a video but it may take him a few days.

 

It went as I suspected, not to sound like a know it all. I will have to look at my previous post on the SS forum to show what I said I would think would happen. It was something along the lines of. I figure that it wouldn't want to make much more then 500 cause the 4.8l can not make use of that much air. Just can't pull it through and make use of it especaily with a stock cam and heads with the small intake valve.I figured it would give up on making much more power before it blew up, with the long rod and short stroke, just not going to put enough stress on the bottom end. Allthough with a very small bit of knock or a lean spot it would give pretty easy.

Godd job buddy glad to see some one really give a 4.8l a ton of hell. Too bad the track is closed with a little spray you migh have seen a 10 second pass with it on the ragged edge.

TJ

 

Parish, this was stock 4.8 internals, right. I'm just asking because at 7#'s of boost I gained almost 1 second in the 1/4 by going to comp 1.85 roller rockers. This was much more than I expected, and I had to change my ve tuning quite a bit. I guess my point is that with a good cam and heads, the 4.8 could probably make obscene amounts of power. I still haven't heard of anyone damaging the bottem end, no matter how much boost. Except for ryan's pulley spinning on the crank, but that was with car pulleys. How about doing a test to see what can be gotten from a 4.8 with a good size cam and afr heads? The small bore should leave the block with a lot of extra meat for strength to hold up to the boost.

 

all i know is i wish i could tune like you for parish way to make us all look like dumb ***** hehe no j/k man keep it up and hurry up with that 408

 

Hey Parish,

Nice work -- very salient write up, too. Were the part throttle problems all in closed loop? I wonder if setting the Closed Loop Enable to a high temp (so it never came on) would've helped? Or was all this with MS?

 

all the fuel tuning was done with the megasquirt, it worked great, the part throttle VE's changed so much with the diferent fuel we didn't want to take the time to make them perfect. mostly we just looked at the WOT stuff.

just my $.02 but i think we would have seen another 50hp at the same boost with just some good valve springs. look at that TQ fall off on the last run. might have pooped out a head gasket too.

i spent way too much money, dyno bill alone was $250, it would be a blast to slap on the 6.0 heads(with patriot springs) and head studs that i have sitting here and then go back. that would probably cost over $300 to try that experiment. when i asked for a few bucks for this fun there seemed to be a lot of people(or a few loud ones) that thought it was inappropriate. it seems to me grouping a few bucks together from a bunch of diferent people to learn what certain parts can take is a great learning opertunity but it isn't worth the hate and hard feeling.

 

thats so evil! i like it! i was very curious on your numbers becuase i myself will be getting a detriot turbo kit. and a few other things. and based on your info (if this is on stock internals) i can handle 12psi with meth. injection and a 3 core. i will be redoing the fuel system and intake system so im excited and pumped thanks guy!

nick