Got bored and wondered...is a cutout or catback really worth it? Is the stock exhaust pretty restrictive? Let's find out!

Pulled the truck on and made some baseline pulls and got a consistant 253rwhp with the mods I have now(descreened MAF, UPD intake and 87 octane HPP tuning)

Then there is a collector right behind the ypipe that I unbolted. Started her up and she definitely sounded meaner! Made some pulls and it has consistantly made 260rwhp and gained 8rwtq in the upper rpms! Guess I need a cutout for now!

<small>[ April 24, 2003, 11:16 AM: Message edited by: Smoke_ur_5.0 ]</small>

 

Did you lose low end torque with the cut out? Did the peak hp & tq move higher in the rpm's?
Jim

 

I haven't driven it like it is but on the dyno it doesn't show any loss on low end torque...I bet if I took off the cats it would loose some lowend. I'll see if I can get the graph up tonight.

 

We've got a real bonafide DYNO ***** in the truck section.....Awesome. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

When are you going to test a heads, cam, headers swap? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

John

 

I'm trying to hold out on the heads/cam swap until 36k miles. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> Who knows if we make it.


I just did a run without the belt...you don't want to know what I got. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

 

WOW! Allright I need to know whats up with your o3 belt removal!

To get that 279 to the wheels what do I need to do?! Did you do this run with the exhaust unhooked too?

What did you remove? The accesory belts? What do these belts hook up to? The alternator, power steering, etc?

I wouldnt really want to drive around with all my belts off so whats the alternative? Pulleys right?

What brand pulleys has anyone heard of and tested for dyno results?

 

Meziere is suppose to be coming out with an electric water pump that is a bolt-on with heater hose provisions for the fbodys. I'll have to check and see if the outlets/inlets are the same on the truck and car pumps. I thought I read something about some differences??

JPR will also be resuming production of his reverse cooled water pump setup. This may take some modifying to hook up to the truck radiator but, shouldn't be too much work. I think all the hoses are braided and cut to length for the Fbody. JPR talks a little about the gains in this thread.

https://ls1tech.com/ubb/cgi-bin/ulti...=007702#000006

John

 

I just threw off the entire belt to see what the accessories soak up and what it possible to gain by getting rid of the accessories being driven off the belt. I wouldn't recommend taking off the belt at all for the track or anything else...you'll cook your heads if you let it run too long without and coolant circulating.

ASP is the only UD pulley I would recommend.

Mark

 

So I think this ASP pulley was good for like 8hp. What pulley does this replace? The crankshaft pulley?


Do you think its worth the cash? If so do you think it would void the warranty?

 

Can you give the hypertech 93 octane programming a try? Who cares if you only have 87 oct gas in there. It will add a few degrees of timing and slightly lean it out.