Built Motor with Paxton Results

Well the truck is up and running and spent some time on the dyno. Two other guys, FstJack and RamfromHell, finished similar setups about a month ago. Both of them could only build ~4lbs of boost and maxed around 650rwhp. My results were very similar to theirs.

Rough engine specs are as follows...
522 Stroker motor
9:1 Compression
Custom grind cam
Full head work (very close to Stryker flow numbers)
Crower roller rockers
Port matched intake with X-metal throttle body
Paxton supercharger with custom piping and intercooler (stock pulley)

We only made one full throttle pull, hit just over 4lbs of boost and only 630rwhp. My numbers are a little lower than Jack and RamfromHell but since I already knew their results we did no more tuning. I got the same boost they did... aka not nearly enough. There was more power left in it but I doubt that it would have broken 700hp. Boost jumps up to 4lbs and stays there.

I think the three of us have established that the Paxton just does not move enough air for a big built motor. The additional internal volume with the extra flow from the heads is just too much for it. If you want big power from a Paxton, forge the motor, VERY minor headwork, stock cam, change to a smaller pulley, and plan on spraying a 200 shot on top. This should get you to 1000hp but build beyond that and you actually lose power.

New build plan coming in another thread.

Damn Joe, sorry to hear that!

What does a 522 built like that run NA? Its got to be 550 600

Joe, your post is really informative.

We are learning a lot recently about the prevailing SC's.

Your experience is very helpful in verifying the experience of others.

When an engine breathes well the parameters of the power adder need to change. I had some pretty good head clean-up done when I forged my engine this past spring...one of the consequences was that the Roe 10 lb pulley would only push about 8 lbs of boost...and it was evident in dyno tuning that I was near the max capacity of the fuel pump/rails.

This process is progressing...but we are very near the point at which we will need a complete new strategy for free breathing engines. Looking forward to reading your new plan.

Lot of work for 650HP Joe...hope all this comes together for you.

I don't understand how those numbers are possible. I have a stock truck outside of a few bolt ons and with the paxton I got 671 hp with a Rowe tune??
Help me understand.

Airflow is the issue...the less restrictive the air flow the lower the pressure...with increased airflow the boost is reduced...so it requires a lot more push from the power adder to get the boost higher.

floridaboy said:

I don't understand how those numbers are possible. I have a stock truck outside of a few bolt ons and with the paxton I got 671 hp with a Rowe tune??
Help me understand.

Click to expand...

the engine is flowing more air. the paxton cant keep up. cant build boost.

one of the biggest problems is the LARGE cam and the heads are too free flowing

So what would this motor do unbusted?

Sorry boosted

Sorry to hear this, Joe. The Paxton has shown it's limits recently...I smell turbo(s) in your future. Good luck.

justins procharger kit there buddy or a sweet turbo setup like mine

Correct the free flowing heads along with an aggressive cam are the biggest reasons for the lack of boost.

For the record my truck dynoed a little over 670hp at the tires with the same supercharger and a stock motor. The only other additions at the time were long tube headers, catless mids, and Magnaflow.

I'm not sure what the engine would make N/A. This engine was built to be forced induction hence the low compression ratio. Best guess is somewhere in the mid 500's on just the motor.

That sucks bro Guess the only way to go BIG is turbo:dontknow: Sorry you guys are having to find this out the hard way

im planning on a built motor with a paxton a little work on the heads(nuthin major just clean them up) and a custom cam. was gonna do a 522 stroker and changed my mind. hoping for 700 on pump gas for everyday driving and spraying the rest.

Did Nowwhat have this same problem? Since he was spraying NOS as well, was that why he was able to go so fast?

patrick

mauiSRT/10 said:

Did Nowwhat have this same problem? Since he was spraying NOS as well, was that why he was able to go so fast?

patrick

Click to expand...

He was spraying a TON of nitrous. His engine was built with that in mind, sleeved block etc. He was using a VERY tits multiport nitrous setup, similar to FstJacks.

Thats what I thought. I was just wondering without the juice how much power was his motor making?

patrick

Ok, I'm going to step off into something that I know nothing about here, but that's never stopped me before...

Seems to me that the amount of boost, as measured by a boost gauge, is (by itself) of no real meaning. In fact, seems logical to me that if boost were 0 that would not be a bad thing. In fact, less boost, to me, would signal a healthy breathing engine since "boost" is actually a measurement of resistance to increased airflow through the engine. Superchargers, as I understand them, attempt to force a given amount of air through the engine. If the engine is capable of taking it all, then boost would be zero, no? That doesn't mean the S/C isn't doing it's job...sounds to me like you just need a bigger S/C to feed your engine more air.

Scrambler1 said:

He was spraying a TON of nitrous. His engine was built with that in mind, sleeved block etc. He was using a VERY tits multiport nitrous setup, similar to FstJacks.

Click to expand...

... and this would be that motor. Maybe a 200/shoot out of the whole, and a 350/shoot to finish...





For my Tuck that dcperformance set-up:
Now I see why Dan didn't even want to put headers on her...she needs some back pressure.
For a streeter she's just fine for me. You don't meet-up with to many guy's running 650/rwhp on the street. Besides she's fun in traffic :argh: :burnout:

Quick