matty b

Hey all, Ive been searching around but havent really gotten a clear picture to what I need to do for my performance goals. I have a low mileage (15k mile) lm7 5.3 from an 06 silverado going into my 64 chevelle. I have installed an 02 Z06 cam and springs for it and plan on a twin turbo setup. Turbos I think will be t3/t4 57 trim with .86 exhaust housings. These are good for about 400 each so I dont think Ill have an issue choking the motor. What I wanna know is what type of strengthening modifications I need to do to the motor to keep it together. I would like somewhere around 475-500 at the wheels and it is going through a 4l60e and 9" rearend. I dont plan to drag race other than to get a time for it and it will spend its days driving the twistys and track days. Id like to run a manual but after a severe motorcycle accident I cant clutch anymore Anyways I know the 6 liters can handle a ton of hp without anything but a turbo strapped to it but didnt know about the little brother. GMPP did an interesting thing with the ECOTEC motors and actually had a table of engine mods necessary for rising hp levels and didnt know if there was anything around even close to similar for the v8s. Like I dont know if I should be changing pistons or rods or both or just rod bolts. Head studs and head gaskets is another thing. I know it may sound like an oxymoron but Id prefer to keep the price as low as possible, I dont want to buy exotic parts or have to replace half the parts in the engine to do it. If thats the case I may just sell it and get an lq9. IF I can make around 500 whp though without much modification could you give me an idea of the best things I can do to keep it reliable? PS when I say low cost doesnt mean cheap, my project is anything but, however I dont feel like buying parts just cause they are cool if you know what Im saying. Just a basic hot rodded motor with the right things on it to stay together no more no less. Thanks

MikeGyver

iTrader: (5)

I'm sure you'll get your answer so I don't think my question will mess up your thread. Would you mind being a representative of the people, and tell me, where do people come up with horsepower goals? Every time I come up with a number, it seems to be only half enough. I think the number that you picked shows that you have done some research, like you have a pump-gas limit, or a no-meth injection requirement, or already know about what 500rwhp will cost. Or have you driven a 600 HP Chevelle?
I just know in my case, when I saw Whipple advertising a 50% increase, I thought "450 HP. Wow! I need 450 HP."

gao8302

iTrader: (13)

Sounds to me like you have been busy with the search button. Anyways i just finished up my 370 build. So if your going with FI i would recommend forged pistons and rods just for insurance. Also get a good set of rings like total seal or file fit. Bearings are up to you and what you what to spend. Clevite are very nice and for the extra ~$150 are well worth the insurance also but a standard set will do just fine.

As far as main and head studs i wouldnt spend the money them. I would just stick with the stock TTY bolt or a set of arp bolts. Head gaskets you can go with cometic if you want the best but a felpro will do just fine with your combo.

The stock roller rockers are fine and i seen that you are going with ls6 cam and with that a set of ls6 springs will do just fine. If you really want to be safe run a new set of 918. Hardened pushrods are also up to you while your in there. Lifters can be reused or replaced and ls7 lifter are a cheap upgrade if you decide to go that route.

The heads flow fine on a stock 5.3 and for FI a good set of heads are not real important.

On a side not im sure you could run a stock 5.3 and get the numbers your looking for but you said you are looking for something that will last. So in short a set of forged pistons and rods should do the trick. Parish built a project car with a stock 5.3 and put a turbo on it and has had great luck with it. But both ways at the power level your looking to get the tune will have to be very very close. So the tuning of the engine should not be over looked.

I hope this helps.

matty b

thats an interesting question. Um well with a target weight of 3200 lbs, ~500 whp will get me down the quarter somewhere in the high tens like 10.8s or so. Granted I dont care about quarter mile times that gives you an idea of what kind of performance youll be dealing with. A ten second car is neck snapping fast and IMO about the upper end of what a street driven car should be capable of. I say that cause a car thats any faster and it is WAY too easy to not only break the law but you can quickly get yourself into a situation where there is no time to react and someone ends up hurt or killed. Its also on par with a 750 street bikes acceleration. If you driven one you probably know its more than enough on the street. I had a modified R1 that ran in the high 9s (it wasnt a drag bike so it was hard to launch) and it was scary. The abilty to go from 45 mph to 100 in seconds is amazing but dangerous. So thats the first part. Second part is that is my limit to how much I feel like stressing the other drivetrain components. There is only so much a 4l60e can take before the sheer torque destroys parts. Third is that most pro road racing vehicles have the same hp/weight ratios. Im talking GT cars not LMP (Le Mans Prototypes like the Audi R10) and they do around high 10 sec quarters and just explode out of the turns, it is one of the most awesome feelings ever. And yes I have driven 600+ hp cars in the same weight range and they are plenty fast and a helluva lot a fun. I am over the days of trying to be king of the hill. In my former life all my vehicles had to be faster than everyone elses in my area. Not only was this insanely expensive but there is ALWAYS someone faster so I finally gave up on the ego tripping and decided that my hp goals are respectable and fun and thats all I care about now. Hope that answered your question.

matty b

cool that helps, I have a question though, is there a forged piston that maintains the stock CR and fits a 5.3? I know I can bore it and make myself a cast iron ls1 but I think that may just turn into something I dont want and that is where you go,"well if Im gonna bore it out why not take it all the way out, and if I gotta get new heads then I might as well get some CNC AFR 220s then on and on. Its fun but I have a hard time with restraining myself in those situations lol My old saying was ," IF your gonna bore it BORE IT and if your gonna stoke it STROKE IT" If I stayed that way Id have a new LSX block and build a 2000 hp 454 but I cant do that crap anymore. So if I do the rod piston combo, is there something thats more or less drop in without have to remachine the motor? More or less Im trying to address the weak links in the motor and call it good. The motor was cheap and really if it pops Im out 800 bucks. I dont wanna spend too much on this motor for just that reason.

gao8302

iTrader: (13)

Dont quote me on this because i used a 6.0 block. But if i remember correct i think a set of 5.3 pistons may be a little expensive. I think they are a custom piston and not a shelf piston if you know what i mean. I will do some searching for this. Texas speed and performance has alot of what your looking for on the internals. Check it out as will i.

350SS

iTrader: (36)

While researching you probably ran across Parish's 5.3 litered turbo fairmont buildup. It really shows what you can accomplish with a stock long block with a cam upgrade as long as you keep the tune conservative with respect to afr and spark and keep the rpms in check. Here's a couple in case you didn't see these:

https://ls1tech.com/forums/showthrea...light=fairmont

https://ls1tech.com/forums/showthrea...light=fairmont

https://www.performancetrucks.net/fo...light=fairmont

https://www.performancetrucks.net/fo...light=fairmont

matty b

yeah parish's fairmonte was definitely inspiration. His low buck approach is a little more extreme than mine but I really wanna only do the bare minimum to keep the thing together. I may just get a set of rods and call it good. Gm does make a niceset of pistons and in larger motors handle quite a bit of abuse so I think I may just reuse em, not to mention WAY less work involved LOL Thanks everyone for the replies and if you got anymore suggestions keep em coming.

gao8302

iTrader: (13)

What are your plans for the trans? I hope your not keeping it stock.

matty b

a convertor and cross my finger lol. I dont want to spend the money for all the upgrades just to have it grenade anyways. And Im not to keen on putting a 4l80e in there for multiple reasons including weight and its ginormous size. I wish I could put a tranzilla in it or a dog gear t56 but like I said I cannot clutch due to my leg being totally Fk'd from having a dumb *** girl not paying attention run head on into me while I was riding my R1 home from work. I have 26 reasons screwed into my hip why I cant have the transmission I really want. Beyond that is there anything I can do to make sure I dont burn it up? The abuse itll recieve will be from torque not from drag racing or launches, I have no interest in hammering on it from a dig so I think Ill be safe(r). Im into road racing so all my performance driving is from a roll. My tranny guy Jim from ATO Transmissions out here in Sacramento told me that with what I plan on doing I just gotta make sure to keep the line pressure up and the temps down anddeal with it. He said that even the 4l65e can only be modified so much and much of the upgrades revolve around strengthening it for drag racng. He said if it gets too bad that I should consider a 4l80e but to ride it out and see how it works. I trust his advise and it will come down to how much torque itll be able to deal with with out it starting to burn up clutches. IF you know of some things I can do to improve its chances lemme know Im all ears.