I ran up to Fastech's new shop this morning dyno my Av. I saw encouraging numbers but there is a bottle neck somewhere. I don't have a scanner so I just charted out the numbers from the graph.
I rounded to the nearest 5 to make easier to compare
Before radix 3.4 pulley stock radix tune
HP/Torque

3000 NA
3200 230/380
3400 245/385
3600 260/380
3800 275/380
4000 290/380
4200 300/375
4400 315/370
4600 320/370
4800 330/360
5000 330/355
5200 340/340

Now 3" pulley with Nelson mail order tune

3000 215/375
3200 230/390
3400 260/400
3600 270/400
3800 295/410
4000 310/405
4200 320/400
4400 325/390
4600 330/380
4800 330/360
5000 340/350
5200 345/350
5400 345/320

Torque looks to be a good bit up and HP takes off early but peters out up top.
Sean @ Fastech seems to think it might just be a total engine airflow issue.
Is anyone else getting much higher numbers with a Radix with stock heads, stock cam and no headers?

It seems to be a little rich which I would much rather be rich than lean.
Its right around 13:1 till about 3600. It drops to 12:1 by 4400 and is stays between 11.8-12:1 til the end of the run

 

Overalll you gained about 5 hp/25 tq. at the wheels? That pulley change alone should have given you 50+ HP gain at the wheels. Hummm something does not sound right, are you sure you think it all has to do with being rich? Let us know what you find out. sorry i dont have any numbers to compare yet, but i know that others on the board do

 

Somethings not right with the tune I would say.

 

If you notice down low it starts making about 20 more HP but ends up about the same at the top. Sean seems to think it might just be pushing as much air as this little motor will handle without opening it up and letting it breath.

I think that 50HP with just a pulley would be pushing it but I would be interested to hear to here what users say. I know there is now power to be found but I would like to know what others are getting with similar stock head/camed 5.3's. I was not able to get a hold of Allen today so maybe I will here input from him tomorrow.

 

I went from a 3.4 to a 3.0 and I would believe 40-50 hp to the wheels, haven't dyno'd recently though. Maybe I will try and make it out there tomorrow.

 

50 rwhp is a little overboard. I am suprised that the numbers weren't higher though. Complete stock exhaust? Did you log the runs and know what your timing was?

How was the new fastech shop? I've seen pics, and it looks nice.

Side note - I asked my barbers about going on the power tour. Knowing I'm into trucks, they made mention ofa guy who had just installed a new Radix on his AV for the trip. Before they could finish, I asked if that person worked at Reliable (thinking it was you). Sounds like it was. Richard and Randy Dodd said they know you from the car cruise / show / hangout circuit.

 

Those numbers do seem a little low overall. I would expect 350- 375 range.

 

Please post your results here. I would be very curious to hear what you get.
What were the results and combo of parts on the last Dyno?


The exhaust is stock except the Magnaflow catback. They didn't have there TechII going yet so I couldn't log anything.

The new shop is awsome! Very nice facility I hope they do well.

Randy is my bud. He is so much like me its scary. I have known him for about 5 years and he always has 4-5 unfinished project cars. We both talk about if we would just concentrate on one car we could both have a really nice one by now.

 

get your problems worked out. i believe i would look to the exhaust flow and possibilites of knock retarding if you were on pump gas.

50 rwhp gain, no way, not a screw type blower. i would look for 20 rwhp and a good amount under the curve (which you gained anyways). peak does tell the story for this type of blower. now go lightning hunting.

 

20 hp from gaining 2.5 lbs of boost and retuning getting rid of that supershits tune? No way! I noticed a huge different from the 3.4 to the 3.0 and a new tune, and I have a hard time believing you can easily feel 20 hp.