LQ9 Questions

[brent1976]

I have a 99 silverado 4x4 rcsb w/ a 4.8l engine. I have been searching for a while, and have found many options new, used, rebuilt, and I think that
this here
is my best option. I have studied up, and read posts here, and on other sites, and am pretty sure it will work. It will be a month or so before it will happen, but I want as much help as possible before I purchase something this expensive.

[RedHeartbeat]

Interesting. Yes, it's a straight swap. Looks like a fun project with many rewards. You'll need to get your PCM reprogrammed for the new engine. I know just the guy to do it. Ever heard of a company called Nelson Performance?

[brent1976]

Yes I have read alot about the stuff he does, but he is in CA, and I am in OH. How long do you think it would take to get it back, because I don't think it would take me long to do the change, maybe a weekend.

Also what other things would you recomend I do while I'm at it. I was thinking some headers, I have stock front exaust w/ split rear cat back, what are the difference between shorty and LT. Shortys bolt to exixting exaust, and long tubes hook to what? Will I have to have exaust work done?

[RedHeartbeat]

He's in SanAntonio Texas and can UPS you a pre-programmed PCM that will not only make the LQ9 come alive but give it even better performance and mileage. Check his website out at www.nelsonperformance.com . He will send you a PCM and you send your's back to him or pay for the core deposit to keep your old one. You will not be down any time due to the PCM.

I would recommend a cold air intake, ceramic coated headers with aftermarket y-pipe such as pacesetters. A nice cam swap would be good if you think you might want to do one in the future, do it before the swap while you have easy access. While you're at it why not swap out the factory torque convertor for a 3000 RPM stall convertor?

[brent1976]

I guess I never thought of that. If he makes it that easy I would probably would use him, he certainly has plenty of cred around here, and on other sites as well.

[brent1976]

You mean these , with this, for the headers, correct.
Umm, about the cam, I would have no idea where to start with that, lobe separation, degrees, duration, thats dutch to me.
On the torque converter, I had thought about that, but don't really know much about that either, from what I have read a 2500-2600 sounded good. Isn't 3000 a bit much for something I will drive every day.

[RedHeartbeat]

http://speed-eng.com/store/product_info.ph...84f555429e25f07 Those are both of the ones you'll need. Shop around for prices. One of our members here says he can get them to you cheaper than anyone. That's a nice service he's providing.

You could get a cam suggestion from most anyone but I'd trust TRTPerformance and NelsonPerformance for suggestions on the cam. You'll need to spell out exactly what you want out of the engine so the they can suggest a cam and convertor size. I run a 3600 stall in my daily driver 408 for what it's worth.

[brent1976]

What is the differance from a 3000 stall, to say stock 1800? Does it shift different, harder, firmer, faster or what? I know the rpms drop less when it shifts, but that can't be the only thing it affects.

Oh, and about the trans, will a 100+ hp increase hurt anything, because I know the 60e is weak when it comes to adding power. Will a torque converter help or hurt the situation, if anything?

You got your wife a sweet truck by the way.

[RedHeartbeat]

Thanks, she likes it. The transmission really needs a set of billet shift servos to help hold the additional HP. The stall will allow the engine to rev up quicker to the stall RPM so that you are closer to where your HP/TQ starts to rapidly increase. Too large of a cam with an 1800 convertor will be a dog at low RPM. A 3000 rpm stall with a factory cam isn't really necessary on a daily driver unless you're like me and like to play at the strip every weekend. It really doesn't mess with the shift other than what RPM the engine will be at when it shifts. The convertor will still lock up 1:1 when cruising on the highway.

[brent1976]

I've often thought about going to the local stip, I have no idea what my time would be. It's only about 30 minutes from here, and everyone says its very nice. Have you ever heard of National Trails Raceway in Hebron, OH.