I'm planning on a total rebuild in a month. My goal is somewhere around 400hp at the wheels. It's still going to be my daily driver, so i don't want anything to crazy. I was just wondering if i could hit this without raising the compression? If so would kinda heads and cam would I need? And would i need to make the bottom-end anything stonger or can get handle it easily? I just want to know what yall think would work. Well, thanks.

 

well if your doing a complete rebuild you might as well swap in forged pistons. if you want a lot of torque maybe stroke it as well. not sure what your budget is. so a simple forged 355 might be all you can afford. thats fine, you can make a lot of power with a 355. youll need either LT4 heads or worked LT1 heads. plan on a 52 mm tb and new and bigger injectors. you may not need the bigger ones, but it wont hurt if you keep it reasonable. dont throw some 42 pounders in there or something ridiculous like that. you will also need the supporting mods like headers and full exhaust if you dont have it already. if you have a lot of miles on the car or fuel pump, id go ahead and put a new pump in there now. its cheap insurance, besides it a huge bummer to get the car cranked and running only to find out you cant go anywhere until you get a new pump. so i say do it now.

i think youll be fine with worked LT1 heads from a good porter not some guy down the road who does them. unless hes a badass then by all means go ahead. maybe a 306 cam or if you want to work with a speed shop see what they have for custom grinds. the 847 GM cam should do well also. for something very streetable id recommmend the ZZ9 cam. you most likely want make 400 at the wheels, but it idles very nicely and makes very good power.

and a general word of advice, dont get caught up in peak power or torque. those numbers are worthless. what matters is area under the curve. the more the better. a peaky curve will not be a good street motor. you want a very flat or long and low arching torque curve. one that comes on strong early and doesnt let up much even up top. horsepower you want to arch up very quickly down low and continue to rise all the way across. that will make for one badass street motor, you may not reach your goal, but itll be a very good street car.

 

I got shot down awhile back for suggesting the LT4 conversion kit to someone else (so don't buy it!)

You should be able to make 400 hp at the wheels with ported LT1 heads, full exhaust, and the right cam (cc305?). You don't need to change compression ratio, and I don't believe forged rods or crank would be needed either. A stroker kit would be another way to go, but I'd suggest just the ported heads/cam/exhaust route. Also, a good computer tune will be mandatory to work with the new heads/cam. If you're not into working with LT1edit, then try finding a shop in your area that can dyno tune

 

Its gonna take most, if not all, the bolt ons and a pretty huge cam with some ported heads to get to the 400 mark at the wheels without boring and/or stroking.

 

With a 15% drivetrain loss, you'd need to make about 470 flywheel horsepower to make 400 at the rear wheels, correct?

I was reading on one of the sponsors websites (the name eludes me for the moment) that their ported LT1 heads 'typically make 430-460 hp with a daily driveable cam'. At least that's what they said, so if true, the ported heads plus a cam to match, headers, Y-pipe, and catback with a PCM tune should get you 400 at the wheels.

 

Its very possible to get those numbers all with the exception of the "driveable" cam. Those are LS1 H/C kind of numbers there. Also, the 15% drivetrain loss is for the M6, remember some of us here have A4's with more like a 20% drivetrain loss.

 

You won't reach 400rwhp with a CC305.

It's going to take heads that have great velocity and a flow in the range of 270~280 cfm on the intake side, and a cam to match the characteristics of the of the headflow and 'honest' use of the car. It won't be a small cam either. 400rwhp N/A is going to lead to a fairly aggressive set-up for a daily driver IMO.

What's your budget?

 

That's a good point about the drivetrain loss; since I've got the M6 I just assume everyone is shifty like me

 

Talk to Lloyd Elliot or Advanced Induction. Both of them are producing pretty budget Head/Cam packages ($1500-1700 I believe) that are producing the power you're looking for.

 

Thanks for info guys. I have 2500 to put into it. And I know 400 rwhp isn't easy to get in a N/A engine, but that's just my goal. I dunno if 2500 is even enough to get that but If it comes out to be 370 or 380 i'd still be every happy. A Head/Cam package sounds pretty good, How would i get in touch with those guys at Elliot or Advanced Induction? If i could find a good porter somewhere around here i'd rather do that but i don't know any yet.
I have thought about a stroker, I know they can make really good power, but I don't think that's in my budget. And I have also thought about putting a 100 shot in it but I just don't want to go to that just yet.
I know some people think it's crazy having something with that much power being a daly driver but my work is only 3 miles away from my house and I'd still drive it on the weekend of it wasn't my davily driver. Well thanks again!

 

Problem is that a stroker isn't going to make any more power than a stock bottom end unless you have the valvetrain/heads to support it. If you're doing it all at once, $2500 is by no means enough for a 383/396 longblock. For a good setup stroker longblock, you're probably looking more at $7-10K easy.

 

I believe that both Lloyd Elliot and AI charge about the same for their port jobs, around $1200 for everything, including new valves and springs.(please correct me if I am wrong) If Im correct, that leaves you a good bit to spend on any bolt-ons you might be missing and a cam to match the flow of the heads. Something else that you might not have thought of is that when you add power to go faster, you also need the brakes and suspension to handle the faster speeds. Plus, without suspension mods, you'll never fully see the potential of all that new power you have.

 

youll never make it if you only have 2500 to rebuild the engine with. exhaust alone will cost over 1000. well for go stuff that wont need replacing in a couple years. what i would do is just do a standard rebuild using forged pistons. get the engine balanced definetly. dont skimp on the important parts like a new balancer if you need it or new opti and water pump. then get full exhaust for the car. if the shop is doing the assembling have them slide in a good reliable cam like the CC305, LPE 211, TPiS ZZ9 or even the hot cam if you like. or do it yourself if your building the motor. and just get the heads rebuilt if needed. also go ahead and upgrade to good 1.6 rockers. crane golds or comp r's. get the lt4 extreme duty timing set. cant remember the name but the upgraded lt4 chain set is what im referring to.

put it all back together and enjoy. save your money and when you can do the heads get them done. those cams i listed are good off the shelf cams that will work with your stock heads pretty well, but with ported heads will do even better.

the reason i say do it this way is simple. you cant make a lot fo power without the supporting mods such as headers and full exhaust. but those supporting mods with help you now. so get the engine built right the first time. dont skimp just to get it done. save your dough and add the heads and maybe a different cam later on.

may i ask what kind of power you are making now and how familiar are you with a powerful car. i mean a 350+rwhp car. i ask because if all youve ever know is a 94 m6 z thats stock. then 315-330rwhp will be a lot of fun and be very fast. you see numbers thrown around all day long on the net about how much everyone makes. but a lot of people have no concept of what the power feels like. and they have this idea that unless they are making a huge number then they must be slow. thats not true at all. the recipe i wrote out will put you just under 350 to the wheels, maybe even hit it if your cars a good one. later on add the ported heads and maybe a bigger cam and youll make even more. but in the mean time i prmise itll be fun with less.

 

Thanks for the info. A guy i work with and me are going to do the rebuild. I have helped rebuild my grandfathers 409 he put in his drag Impala. And my friend has rebuild acouple of engines himself. So i'm pretty confident we can do it eaily. That helps with the cost alittle too. And the 2500 in just for the engine, i have more money saved for the bolt-ons and suspsension. And I've driven cars alot fast than mind. I have driven many of C5 at my work(cann't wait for the C6), rode in 2 Z06s, and i have driven my grandfathers 409 impala to many shows. So i kinda have an idea how how fast i want it.I still have a month before it's going to happen, so i have time to get the set-up best for me. Thanks for the help.

 

ok cool well good luck with the build. i hope it turns out well

 

umm...why on earth would anyone want to settle for less power??? maybe im the only psycho in here (doubt it) that wants the meanest street legal car possible. but he is right about not skimping on balancing and parts. your newfound power will waste a stock timing set

 

oh and by the way, anyone reccomend a good head and cam package?? im also looking for a package for my 95 formula M6. or a good lopey cam that matches well with stock ported units. im gonna need all the help i can get if im gonna keep up with my dad. (69' chevelle SS, 468 4spd muncie,torque monster!)

 

I hear you man. When i first did the heads and cam package i went with a VERY small cam 224/230 and thought i would be happy with it since it wasnt such a radical cam.....that dumbass thinking went right out the window the first time i got beat. I should have gone big and ***** to the wall to begin with. Being streetable is all a state of mind. If the thing idles in traffic without dying, and AC blows cold...then its streetable! I have buddies running cams up in the high 590's lift and 250's duration with ported heads, full exhaust, suspension, and stock blocks.....and theirs drive every bit as good as my little mild cam with mid lengths with bolt ons but run like raped apes compared to mine. All this junk about "is this cam too big to be streetable" and stuff like that just makes me laugh...you can make damn near any cam streetable, hehe. Go BIG, go BAD and go FAST!

 

That's exactly the way I feel.

 

exactly. if you're doing a rebuild, you had better kick that thing in the nuts or else you'll be dissappointed when a stock LS1 beats your mild cam and you have all that money in it. my goal is 400 also(at least) and ultimately to be able to take out stock C5's cause theres nothing worse than being beaten by a mid life crisis corvette driver with an automatic and a heavy velcro-strapped shoe