12.59 @ 106.1 and I weighed in at 4200 lbs that night.

Hit up Google with 'horsepower calculator' and see for yourself.
Second thought, I'll save ya the trouble:
http://www.google.com/search?sourcei...wer+calculator

Cam and headers is the only motor work I have done. The cam is small, heads were stock, as well as the pulley (3.4"), hence me only getting 7psi.

So ... you're saying that you haven't had any problems from your motor/tranny as of yet? Do you have a shift kit in it? Do you not think there will be issues with the tranny if it were behind a strong 408?

 

I'm not doubting anything, just expressing surprise. That's a great time, those are great numbers. I think it's great you got 160-185 RWHP from a Radix, headers, and a cam. Congrats. What cam BTW?

My tranny is fine. I'm sure it has less wear than other guys' who don't have a Radix because of how I drive. The 4L65E will be better, though, in the long run.

Regarding 408, that's a whole other animal. When I do that evaluation, I'll be looking at my entire drivetrain from flywheel to the rear axle, including tranny, driveshaft, and that stock GM 10-bolt.

 

This was my point. That is an incorrect statement. This guy was asking about a RADIX and you go ahead and say that the 5.3 will not be able to produce any power in that range. You then immediatly followed that by saying a trans will not live behind a RADIX'd motor, which obviously is wrong since you have that same setup and have not had any problems yet.

 

Okay, now I see what you're saying. Sorry for misunderstanding.

The Radix alone at its most optimistic will only produce 110-120 RWHP. Add that to 240 RWHP from your average 5.3L and you end up with 350-360 RWHP. That's far short of his desired 450 RWHP.

If you expect to get another 90-100 RWHP out of a 5.3L you've got a lot of work to do, more than headers and electric fans and an ASP pulley will deliver (which are pretty much the only other bolt-ons this guy has). At this point you're looking at cam, heads, and/or perhaps a smaller Radix pulley. And we don't know if he's willing to do that or not.

The fact you got 7 psi from a stock 3.4" pulley is interesting, because most people only see 5.5 - 6 psi from the stock pulley. Even with everything you did, you say you only got 400-425 RWHP. This guy says he wants 450 RWHP.

So you can do it the hard way, with a 5.3L, really stretching its limitations. Possible? Yeah, I guess it's possible. Convenient? Probably not. Driveable? That's a good question.

Or you could get a crate LQ9 for $3500 and bolt a $5000 Radix on it for about 400 RWHP and go from there for more ponies, or you could build a 408 for about that same price (or even less) and get 450+ RWHP, N/A, as soon as you drop it in.

It's all about choices man. And I'm assuming he wants to go the most efficient and effective way possible. But who knows, maybe he wants to work on his car all the time? He wouldn't be the first one here, I know that.

 

And I have no idea where you are getting this statement I supposedly made.

 

That's what I assumed you were getting at when you said that. I guess you were genuinly concerned and asking a valid question there.

What says he's willing to build the rest of the shortblock. Let's start the cost at an average of 3800, add 2000 for heads, you're already above the costs of a RADIX. You still have a cam, the rest of the valvetrain, timing chain, oil pump, etc, which I'm sure if tallied up would come out to about another grand. If you plan on selling your 5.3 after the swap as a complete motor, you still have front and rear covers and the valley cover as well as some other things.

So much for it being a 'little' more.

How's that? Magna advertises it to put out 7.5psi on a stock 5.3.

That's where me saying it was the stock pulley came in. There's still plenty of room for more power by adding a smaller pulley.

Bottom line ... the RADIX is very capable of putting out some power, even on a 5.3. It will take some work, but in the end, it's very streetable and fun to drive.

 

I'm of the belief the Radix is often dismissed prematurely as a true big power maker.
It can make big RWHP numbers!
I think BlownChevy was on his way to finding out what the potential was, but changed his outlook on what he wanted from a street truck before he could finish.
Remember, he had just finished the 4l80e swap when he sold it. I believe there were plans for at least a new valvetrain. In fact, I don't even think he was at a point where the intercooler needed upgrading or augmented as many do with other systems (i.e. larger I/C, water/alch inj).
Heck, even the bulletproof 4l80e he put in, if I remember right, could have used a steeper first gear, more to his liking and thus similiar to the 4l60e's first gear.
plenty of room to grow here, uncharted waters folks.
but there's alot of frusrtration that goes along with braking parts(repeatedly), i.e. tranny and what not, and you gotta know when to draw the line.
Lucky for us we have some, REAL WORLD, experience to learn from. Like, get the dang 4l80e, with the steeper first gear if you can afford it, especially if you plan to beat on it.
Maybe, a 4HI 1/4 mile would have net an even more impressive E.T.
Weren't you still trying to find traction B?
The LQ4 is, IMO, the perfect platform to exploit the MP112.

haha, good thing I came along. Just so it's out there, my first goal with the Radix is 400 RWHP, then I'll bump that in additional 25 RWHP goals until I feel it's not as dependable as I'm comfortable with, then I'll back it off a bit.

 

ET isn't a very accurate way of figuring rwhp. Someone with X amount of hp could put in a big stall, and go 5 tenths faster with the same hp.

With a mph calculator, 4200 lbs and 106 mph comes out to 340rwhp. Most people say thats a little low because of a trucks wind resistance. So maybe 370rwhp.

 

I was just using what the first paghe of calcs averaged from the Google search.

I was using 4200 for weight and plugging in both ET and MPH. I figure that way was more accurate than me guessing.

 

Well, yes, I was. No need to read too much into what I ask/say, I'm not the obtuse type. If I have tranny problems, I'll say..."Yo, my f'ing tranny's taking a dump!"


Well, that's a good point. But I'm not sure a 5.3L will get him 450 RWHP, and even if it does, it will take a lot of work to get him there. I'd sure like to see it. Problem is, once all these guys here on LS1Tech build all these kick-*** trucks, they either sell them or break them before they get them on the dyno. So we never really end up seeing what they are really putting out. Not like the F-Body guys in this forum - those guys drag and dyno all the time, and they help each other that way.


Can you point this out with a link? When I was at Magnuson getting my truck tuned, they told me 5.5-6 psi is all I could expect with a 3.4" on a 5300 Vortec. So I'd like to know where you're getting your number.


I'd like to see some dynos. TByrne says 15-20 RWHP for every 1/10" smaller on the pulley, but I'm not buying it. That would mean 60-80 RWHP more with a 3.0 pulley, 75-100 RWHP more with a 2.9 pulley. How small have you gone on the pulley?

The Radix starts losing efficiency pretty quickly once you start spinning it higher, so I'm in the 'show me' camp as far as this parameter goes. Like I said, I'd like to see some dynos.


I agree, my truck's a lot more fun to drive than when it was stock, but I'd be lying if I said I was happy with it. But hey, maybe that's one thing we can all agree on - too much is just not enough, and that's why we're here....