A nice top end can get you 400 RWHP, be quite streetable (esp. since you have M6), and be re-usable in the event that you decide to add a blower. The following is just a suggestion, but I believe it should meet your requirements nicely:

LT4 heads, ported & polished (maybe milled for higher CR?)
CC306 114 LSA
1.6 RR, upgraded springs, pushrods, etc. might look into AFR Rev-Kit
Full exhaust
LT1-Edit or Tuner C.A.T.S. software to edit PCM (ODB-I conversion, maybe?)
Electric water pump, CAI, 58mm TB

Only issues I see with this setup are that the CC306 114LSA is not the best N/A cam, but it offers better driveability than the 112 or 110 LSA and the added benefit of being useful in a SC motor. You could avoid this by putting in a Extreme 230 or 236 cam with 112 or 110 LSA, and since you're tearing the motor apart later to put in the SC, wouldn't be too difficult to swap cams and you can sell the old cam on here to lessen the pain on your wallet. Also, you don't need to worry as much about idle w/an M6, so running the 110 LSA won't be as much of a hindrance to drivability as it would in an A4.

 

You do not need to remove radiators and a lot of that stuff to install a supercharger... if you are going to go with a supercharged later on, choose the supercharger cam NOW.. it will still be better than stock and you will have less work later on.

 

Hmmm for a 5k budget you should be able to all that you want ,(heads cam and supercharger) if you bought the stuff used from other members. I see stuff like this all the time in the “for sale” section all the time. People are always upgrading and selling off their old stuff for a fraction of the price. Take me for instance I just popped my motor and I decided while I was rebuilding to get a bigger cam for my blower set up and I sold my cam for $135 vs. about $300 new. Roller cams don’t go bad unless there was a mechanical failure etc. I bought my supercharger from a board member for a fraction of the price (about 1100 with only 4 k on it).
So before you can go crazy check out the “for sale” side and see what’s available. 90% of us are honest so you can really score some good pieces on the board for a fraction of the price and still stay with in your budget


Ok after I said all that….. You wanted to know whether or not to go N/A of SC,

Superchargers,

Well I think certain people have different experiences with sc then others… the problem with having a SC is that you become greedy with boost and blow a piston trying to squeeze every once of power without having the right tune to go with it.

Take me…. I started with a 4.5 PD on my stock motor with about 32-35 k on it. I did not take all the precautions like upgrade the fuel pump and using timing retard I just relied on the fmu to do the fuel enrichment work (noooooottttttttt) FMU’s suck. Any good tuner will tell you that. My motor only lasted about 20k before I toasted three pistons. Instead of rebuilding the motor I decided buy a short block from anther board member with forged pistons arp rod bolts etc for about $1100 which was a steal because it came with a cam made for a sc and billet timing chain set. All I did was add a smaller pulley to make more boost and headers … (bought the headers used also)
That motor made awesome power but only lasted only lasted 20k before I popped a head gasket and killed a piston ring land. I think I am the exception because I do allot of racing and I hammer the motor every single day … (no joke) and a combo of bad gas, hammering it on a 90 + degree-day with the a/c on also did not help. Also my tune was on the ragged edge. (To lean)


Take my friend Claude (Screen name 95 Silver TA) he took all the precaution that I did not (well at fist) he added and better fuel pump, injectors and timing retard box. And he had no problems. The only reason we pulled his motor was to replace it with a 383 (nothing wrong with old motor). He added the sc on his motor with around 92k when we pulled it out it had about 120k on it. I almost fell over when I pulled his motor apart because there was hardly any wear on the bearings or cylinder walls etc. That goes to show you that if you are smart it will hold together. And don’t get greedy on the boost and keep it around the 6 –8 psi inter-cooled. If not inter-cooled stay at 6psi and you should have no problems making 400 hp. And if you drive normal you will still get great gas mileage.

I hear all the time people blowing up their motors but about 90% of the time it's because of bad tuning.



Cam and Heads;

The only problem I have with large cam/heads is the everyday drive-ability factor. For you to make 400 hp you are going to need a decent size cam. (Sorry lt4 hot cam is not going to cut it and I don't care what anyone says but it is a weenie cam) To make on honest 400 to the rear wheels you are going to need a cam with about 224-intake duration on a 112 lsa, which produces a nice rumpty, idle but also produces cam surge and soggy low-end performance. But with good tuning you should be able to eliminate some of that. Also the other factor is bad gas mileage due to the over lap. No way around that. Gas mileage will suffer due to the 112 lsa etc . With my sc set up I can still click off about 26-28 mpg (6 speed and 3.42 gears)


Each option has it’s pro and cons … but for me I am additive to boost… It is much easier to live with everyday then a large cam and head set up. I can have my cake and eat it too (awesome power and a good everyday car).
I have gone both ways and I enjoy my sc set up allot more then the big cam method. Don’t get me wrong I love the rumpty idle but try to live with that every day and it gets old quick, with a sc you can retain a sort of stock sounding motor with well over 400 horses tucked under the hood that would out run most people on the street.
Let me know what you decide and if you need help picking out the right combo for either way.

Jim

 

Maldo
Was Claude running a high octane mix (fuel)? For an added precaution?

 

Its me...Claude
I was always running 92+ octane....Most of the time 93 octane.

 

Sounds good, I always hear horror stories on this site about SC's. Just curious if you ran a mix of high oct or not, thanks for the reply.

 

Since many of you have gone through these decisions, your input is greatly appreciated. I am still considering the SC option with heads and cam. I am thinking of starting with a nice set of used AFRs with a 224/236 114lsa cam as Highlander suggested. While I have the heads off I can port the intake and put a 52 mm TB on it. Then I would try and buy a used SC and keep it at 6# or less with the proper tuning. I think this will give me the 400rwhp that will hopefully last.

 

I flipped through some of my old GM High-Tech magazines (October 2002) and came across an article were they bolted on a Vortech 6psi non inter-cooled system on a completely stock 1996 z/28 (the only thing they was a cat back exhaust) With a little bit of tuning they were able to pump out 390 hp and 392 ft pounds of torque to the rear wheels. According to the article the owner did not want to push over 5700 rpm due to the mileage on the motor but they said that they should have reached the 400-hp mark if they were able to spin the motor up to 6000.

I read GM high-tech but I am not always a true believe in some of there articles because I feel that they sometimes favor the manufacture they are tests to sell some parts and ad time, but from my own experience I agree with numbers achieved in this article.


This is what I would do to achieve your 400-hp goal.

Go with a cam. (Comp extreme 224/236 114 lsa (low lift version) is a great choice).
Vortech or ATI 6psi non inter-cooled or 8 psi inter-cooled set up. (I favor inter-cooling on any blower install but if you are unable to get one without an inter-cooler make sure you pulley down to 6psi. Anything above 6psi you are looking for trouble with out an inter-cooler.

With those two items you should be able to meet your 400-hp goal with ease.


Know if you get a killer deal on set of heads then go for it but the stock lt1s are pretty good for your application. You would be surprised how many people who are running stock heads with just a valve spring change who are pushing 500 hp just one word of advice (stud the motor when installing the heads) stock head bolts suck and they will stretch (it is cheap insurance for a $160 to keeping the head gasket in place) trust me I have learned the hard way. To tell you the truth I would stud the motor either way (you can simply pull the bolts out and replace them with heads still on the motor) it’s a pain in the but it’s worth it.




As always my 2cents


Jim

 

OK..RkyMtHigh, huh?

Does that mean that you are at a high elevation?

You may be able to get close to 400 corrected RWHP with a VERY good, high quality, agressive heads/cam/headers package, but your car won't perform nearly as well as others in this forum who are making that figure at lower elevations. You'll be doing well to run high 12s in Denver.

I have some experience, through my brother's LT1, with going the N/A route on the stock displacement. Right now, we have a CC306, Hooker Long Tube headers, Ed Wright tuning, and locally ported heads. We've spent a ton of money on different set ups..my advice is to not BS around with a hotcam and some of the other lower level stuff. You're not going to get near 400rwhp with that. We're only getting mid 12s ~113 mph out of the LT1 on drag radials. We are going to have the heads re-worked next month. In the end, with the tinkering and changing of parts, we would have been better off going the blower route. A lot of people get N/A go-fast parts..aren't satisfied, and go for better N/A go-fast parts..and finally either go in to the block with a stroker motor or go forced induction. There are too many people with cars in the 13s and 12s with set-ups that are "supposed" to run 11s, as others have done.

In high elevations, a specific N/A setup will pull in the same volume of air it would in Dallas..but the air is less dense, so you get lower performance. This is why turbocharged cars have an advantage at high elevations..you can set the wastegate to limit boost to a certain PSI figure..boost will build until that figure is reached. A turbo car can build 8 pounds/in2 of positive manifold pressure in Denver or Dallas and produce the same amount of power..it is harder to build the boost at the higher elevation, but you can still do it. Similarly, a blower setup would use a smaller belt in Denver than would normally be used to produce the same level of boost.

A forced induction setup has a distinct advantage in a low-density air climate like Denver.