There is an article on Chevyhighperformance's website about some mods they did to a stock Chevy Truck (with the LO5). http://chevyhiperformance.com/techar.../148_0307_tbi/

They added an Edelbrock RPM series catback, march power and amp underdrive pulleys, K&N intake, and a jet chip...and they gained 20 RWHP.

Would someone yield similar gains on the LO3? Now i know the off the shelf chips are ****, so by just adding a catback, open element and some power and amp UD pullies give us such a big increase? I mean correct me if im wrong but the LO5 and LO3 are fairly similar and should respond similarly to some mods, right?

 

Yes it is very possible. There should be a few graphs here on TGO that confirm this. IIRC the normal chassis output for a full bolt on LO3 with tuning is near 170 to 190hp or so.

 

Wow thats great. Shifty you know what ive been planning to do to my car..but now im even more pumped!!

I'm doing an open element and cat-back for sure, and if i can scrounge together any extra money i will end up with either a hi-flo cat or UD pullies. It would be awesome if i could get 15-20 HP from those mods. Then with headers and custom tuning down the road!!!----Dare i say 30-40 total HP??? I'm Pumped!

 

You won't see over 30 with every bolt on and tuning. I would save your money on the UD pullies and put it towards headers. That is where you will see the largest gains. You have the right attitude about chip work. You will be much happier in the end. 200hp and 260lb ft in these cars is a lot of fun.

 

Yea...i know for a fact i cant get into chip work until the summer. Ill be going to college in the fall and im gona be getting a laptop in the summer. Id like to also get headers in the summer. Ideally id like to have a tuned, full exhaust LO3 in time for the east coast f-body nationals. I really don't plan on doing much past an exhaust/open element/and eventually a different rear end to my car, so the UD pullies were just an idea to possibly squeezing a few more HP outta my car without touching the engine.

But do you think its possible to make 20HP from the open element, catback, UD pullies, and maybe a cat WITHOUT tuning (For the time being)?

 

Eh.... It will be close. Your biggest gains will be from headers and tuning. The mods you have listed will help though and you will love them none the less.

 

And if they had added only the catback and K&N, and done the FPR mod ?? They would have gained most of the 20.



Proportionally to displacement, yes. IOW the gain would be multiplied by approx 305/350, so you'd get more like 87% of the gains.



The underdrive pullies are not, IMO, worth it. That's why, also IMO, why Carcraft buried the chip and UD pullies in with the exhaust and air filter test ... to make the unsuspecting consumer think that you need them all.

You're correct. ECM tuning would also extract a bit more based on Fast355's observations on a Cad stock LO3 tuning exercise... but they didn't do that because they used the Hypertech chip.

 

Mack6, I've done pretty much everything you're considering over the past 12 months. IMO you'll get the biggest gains in SOTP feel and track times with headers/cat back and changing rear end gears, not to mention the fact the little L03 will sound a ton healthier with the exhaust mods. Your sig says you're running 2.73 gears. I gurantee that switching to a 3.42 or 3.73 ratio will snap your neck more than anything else you've mentioned. The U/D pullies (March aluminum) look pretty, but that's about it. I'm working on the chip tuning right now. I'm finding soome pretty good gains can be found by optimizing fuel and timing with 93 octane and a lower temp thermostat.

 

Yea i'm aiming for headers in the summer... I just need to get a catback on there ASAP because i don't like how quiet the stock exhaust is.