SC vs. N/A

I am interested in a very streetable car that produces 400RWHP running on pump gas but have little experience with this stuff. I have a 97 LT1 with 35,000 miles on it and an M6 tranny. I am trying to decide which would be the most cost effective way to get there. I have been seriously considering a 8 psi w/ intercooler/aftercooler ATI or Vortech super charger on my stock motor as the most cost effective way to get there but reading the posts it appears that it is only a matter of time before you end up in the rebuild club. My mods to date are 4:10's in the rearend and long tube holly headers with the appropriate fixins. I have a $5000 budget to try and reach my objective and have been wondering if there is N/A option like a stroker that might be cheaper in the long run. Reliability is a major factor. If I have to plan a rebuild in the beginning would not it be better to build the right motor rather than trying a bolt on? Seeking the advice of the many who have already paid the price.

If you have a $5000 budget then I would recommend going with a nice head and cam package. Blowers are great and make huge power but unless you have the money to rebuild your stock shortblock then I would not go the blower route. I think 400 rwhp should not be a problem with your budget.

here you go - the perfect solution
http://web.camaross.com/forums/showthread.php?s=&threadid=71712

A stroker motor isn't necessary to hit your target power goals n/a. A good heads/cam set-up will get you there.

Thanks for the input! The heads and cam option sounds like the better choice. What are some tried and true packages that are complete systems designed to function together?

Jim Pace sells the LT4 kit. It comes with LT4 heads, matching LT4 intake manifold (powder coated red), LT4 hotcam kit, and some gaskets. It is around 2 grand and should make around 430 horse if it is tuned correctly.

My car made 330 rwhp/rwtq with the LT4 kit mentioned above. Probably would have dynoed 10-15 more HP after I did some tuning and straightened things out.

ED Z28 what mods did you make to the internals to run 12# boost and how much money did you throw at it to get you there? I am still very interested in the SC option because like everyone else I want to go as fast possible on my budget. If I can build a power plant that produces 530rwhp and is dependable and within my budget GREAT. If I have to stretch my budget a bit to do this right thats ok. But as everyone probably knows these things have a way of taking on a life of their own, so I am trying to set some realistic goals on the long term total costs. If it is cheaper to do some mods up front before I blow the thing up, I am all ears. If I have to tear whole motor apart to get there wouldn't it better to just build a stroker than a SC.

If I were you, I would go heads/cam. I have the AFR LT4 heads, LT4 intake and hotcam, and with 190,000miles and a stock program, the car made over 360rw. A better cam, fresher motor, and good tune is a sure fire 400. You would be underbudget with that setup. Put the remaining cash in a warm spot and let it grow into enough money to build a forged motor, and then put a blower on.
Get a BBK TB similar to mine that whistles and you have yourself a 400rwhp car that sounds supercharged.:)

Originally posted by RkyMtHigh
ED Z28 what mods did you make to the internals to run 12# boost and how much money did you throw at it to get you there? I am still very interested in the SC option because like everyone else I want to go as fast possible on my budget. If I can build a power plant that produces 530rwhp and is dependable and within my budget GREAT. If I have to stretch my budget a bit to do this right thats ok. But as everyone probably knows these things have a way of taking on a life of their own, so I am trying to set some realistic goals on the long term total costs. If it is cheaper to do some mods up front before I blow the thing up, I am all ears. If I have to tear whole motor apart to get there wouldn't it better to just build a stroker than a SC.

Well, it is not just money invested in the motor, you must consider other things like an adequate fuel system and exhaust. Your fuel and exhaust system must be up to par if you are going to make this much power. I designed and built mine to handle anything thrown at it. You just can't afford to run lean at these power levels.
My bottom end consist of trw pistons, h beam rods, and a stock crank w/arp bolts. Hopefully the 2 bolt crank will hold up, it has so far big time.
Actually, it is a 12 pound pulley, but I am only seeing 10 pounds of boost with that pulley. The addition of a solid intake pipe may pick up the 2 extra pounds to give the advertised 12 pounds of boost. With another 2 pounds and some tuning I could be around 550+ rwhp. On my last dyno I was running rich.
My advice to you and a lot of other guys is look at the overall cost. It is actually way above 5 grand. Probably 15 grand if you go all out on the bottom end and fuel system. Here is my breakdown:
-built 355 short block, 2 bolt main................................$1500
-cylinder heads............................................. ............... $1500
-supercharger kit w/intercooler....................................$40 00
-fuel system............................................ .....................$1000
-exhaust system............................................ ..............$2000
------------------------------------------------------------------------------
TOTAL $10,000

You can save some money by porting your own cylinder heads, but you have to know what your doing. All the other stuff you should not skimp on IMHO. I have easily spent this much money on my own setup, I lost count some time ago.

I say do the heads and cam. I've been thinking about the following combination for reliability, emissions, idle quality, torque, and power:

383 with cast crank, 5.7 rods/ARP bolts, and 18 cc dish pistons
Either LT-4 heads ported to 280 cfm or AFR 210's
Comp Extreme Hydraulic roller 214/224 112 LCA
Port matched LT-4 intake
1.6 roller rockers
1 3/4 headers
Bolt on's

This combination should be good for around 410 - 430 rwhp and gobs of torque with a stock-style idle and emissions legal to boot.

Mike

Thanks for all the input! The N/A is sounding like the ticket. Engineermike you show an T-trim in your signature, are you thinking about giving that up for a 383 or putting it under the blower?

The 383 idea is for my friend's '95 Z28, which only has bolt-on's currently.

I had a 383 with 11/1 compression and AFR 210's in my last car, which was an '89 Firebird. This car, with a Crane Hydraulic roller cam (234/242 at .050), a Victor Jr. and a carb. ran 11.09 at 122.7 mph all motor. This combination made 435 rwhp.

I figured that you can build an LT-1 with essentially the same combination, but with a milder cam, a better exhaust, and a 6 speed to put about the same rwhp and mph, but with better idle quality.

Believe me, I'd like to put a 383 in my Z28, but I already had a forged 3.50 stroke crank and 25 cc dished Wiseco pistons sitting in the shop and ready for my LT-1, so the 383 conversion would cost me a bunch of money.

Mike

If you have enough $ I would go with the SC setup and a 383 for 400rwhp.. I think it would be a lot streetable than a NA since you can almost have both of both worllds.. you would need 6psi so intercooling is not necessary, thus avoiding a lot of installation stuff... anyways either way is nice way

I am still thinking SC because I know once I have reached a certain level of power there is a better than average chance that I will want more. The dyno numbers I have seen from the basic head and cam package do not easily reach 400rwhp. The riddle that I must answer is which way to go first without limiting myself to much for a future mod which I may want when the money is available. If I go heads and cam for power to start with, it probably will not be what I would what in a blower motor. If I put on the SC with only 6# then put the heads, cam, and pistons in the future I risk blowing the thing up before I have the money to do it right. The question is how to best build on the motor a step at a time while increasing my power to achieve a well built SC'ed LT1?

Remember that the most important thing on a car is the cam. The cam will dictate the way the car will react to your foot and to its own way of giving out power (ie driving).

A good SC'd cam is not a good NA cam... probably will work better than a stock one, but will not yield its full potential...

You can work the heads and install a SC cam... for instance an XE cam 224/236 114lsa as I have. It will work well for a NA but not to its full capacity. But when you do put a SC this cam will shine in... As Rich might say.. you dont want to blow out your expensive boost out of the exhaust with the 112-110 lsa (more overlap).

But you can do it one step at a time...

Just use the supercharger cam first, so you dont have to do that whole work AGAIN...

Senior Highlander which AFR heads are you using?

This discussion has me asking myself "what if I had gone N/A". So I've got to know some things here. My stock SC'd LT1 makes 402 RWTQ at 4,400 RPM .....and about 410 lbs of torque at the flywheel at 2,200 RPM (350 RWTQ). Could a mild heads/cam motor put out comparable torque or would the comparison be limited to high RPM and midrage? It kind of makes me sick that an N/A motor (say a CC306 with really good heads, TB, tuning, etc) can actually make more top end than mine. But what about say .... 2K to 5K RPM? Would mine at least own an N/A motor in that range? (about 400 lbs torque at the flywheel at 2K RPM and 435 flywheel HP at 5K RPM). I would think an N/A motor would have less response at the lower end and obviously less vacuum and off idle response (not nearly the MPG either) ......so did I reap any benefits going with the blown/stock LT1 over a cam/heads version? I have to admit I wish I had the cam sound and the extended RPM range with some 4.10's and a 12-bolt .....would be more fun to drive maybe? Someday when this thing pops a piston maybe I'll do it all :D Need a better paying job first so I'm praying it will hold together for a couple of years or so :o

Engineer, I wouldn't recommend that your friend put together that combo. The car would run no where near what it should run. The cam you have chosen does not look like a NA cam and is much smaller than even the hotcam. I just think that would be WAY to small for a stroker motor.

I just can across a great deal on some parts to build a smoken 383. It looks like the SC option will have to wait for another motor. When I am finished later this spring I will post my dyno numbers and costs to see how they compare with what people spend on the SC kits. Thanks for all the input!

Kreinmc, the cam is fine. The duration of the 214/224 Extreme high lift lobes (31XX), when measured at .200" lift is very similar to the famous CC306, but the Extreme cam has more lift. The "small" Extreme cam has .565" lift versus only .544" for the 306. So, the two cams have very similar areas under the lift curve, but the Extreme has shorter duration, so it will give better low end and the same mid and top end as the 306.

Also, I'm running the Crane 210/224 cam. This cam is smaller and NOT and Extreme cam, so the area under the curve isn't that great. But, I managed 340 rwhp with a set of mildly ported stock heads and shorty headers through an automatic. If I had upgraded to a stroker, got better heads, a more aggressive small cam, and full-length headers, 400+ rwhp is entirely possible.

There's alot to be said for cam ramp rates.


CANBAUFO, if the cam is well matched to the compression ratio, a NA motor will make more low-end than a centrifugally supercharged motor. This is evidenced by the fact that most supercharged LT-1's make great rwhp, but don't run as well as their same-hp NA couterparts. 410 rwhp will put a NA full weight car over 120 mph in the quarter, but S/C would need 430 because of the lack of low-end and mid-range.

Mike

Originally posted by engineermike
CANBAUFO, if the cam is well matched to the compression ratio, a NA motor will make more low-end than a centrifugally supercharged motor. This is evidenced by the fact that most supercharged LT-1's make great rwhp, but don't run as well as their same-hp NA couterparts. 410 rwhp will put a NA full weight car over 120 mph in the quarter, but S/C would need 430 because of the lack of low-end and mid-range.

Mike That's a little depressing :cry: .....just how serious of an N/A motor are we talking about here? Would it be nearly as streetable as a blown stocker or are we talking "shaking out your fillings at idle and sucking gas"? So for example, a 350ci N/A motor with a CC306/good heads with everything matched up and tuned right would make more than 350 RWTQ at 2,200 RPM and more than 402 RWTQ at 4,400 RPM......AND more than 400 peak RWHP Really!? How high is the redline with the CC306....like 6,600 or so?

I'd say that there are reliability, tuning, and headache advantages to the supercharged stocker.

You can install a supercharger in a day, whereas a stroker will take a month or more to complete start to finish.

The NA cam would need to be 220+ duration and wouldn't idle bad, but worse than stock.

Strokers require extensive machining, clearancing, and other headaches.

Tuning is much easier with a S/C since it comes with an FMU and retard box.

All said, if I had to do the work myself, I'd go supercharged, but if someone else did it, I'd go N/A.

Mike

Thanks, but I'm not inquiring about a stroker here. Just stock short block vs stock short block/ N/A heads/cam/350 vs 7 ~ 8 PSI/350. I seriously doubt a heads/cam 350 with the same max power as mine makes as much torque from 2 ~ 4K RPM. Besides, in a race you aren't dipping below 4K RPM so what does the low and midrange really matter except for coming out of the hole? (which our cars try to do too quickly anyway). I would think the biggest advantage of a heads/cam motor over one like mine would be the extended RPM range and corresponding ability to gear lower and stay in the gears longer. I knew a stroker would be the way to go but that didn't fit my budget and still doesn't. All in all since I had someone else do most of the work I think heads/cam would have cost just as much but actually been easier to tune and more reliable (had the work been done right). I only had 37K on mine when I did the charger so I couldn't justify breaking into the motor. Now I could see it being more practical though.....because the stock crank and rods would have been fine to use for quite sometime. Now my pistons are on borrowed time :o

I guess what I was hoping is that my setup is more streetable/better MPG/ .......AND ......more torquey in the low to mid range. That's the only thing that makes me feel better about doing it but now you're telling me a heads/cam 350 has more bottom end ?!? :cry: ....oh well.

Since a centrifugal supercharger builds boost with rpm, you'll find that at low rpm, very little boost (and power gain) is being developed.

A heads/cam NA 350 with increased compression ratio and a well matched cam will make more low-end than stock. So, with a centrifugal only making 2# boost at low-end, they are comparable.

For comparison, my previous car was a 3rd gen with a 383 NA full weight and ran 11.09 at 122.7 mph. My new car is a 4th gen with 355 SC and ran 11.60 at 121.5. They both made very close to the same amount of horsepower and have the same torque converter and have similar weights. But, the NA car had a better mph and a much better et due to the better torque curve of the NA motor.

Mike

Yeah, I know what you mean about centrifugal blowers not making much until they're up in the RPM range. However, even at 3,000 RPM mine is already making 2.5 PSI ......not bad for a low PSI blower. It's a little hard for me to believe that a mild cammed 350 with similar max HP could make that much torque at 3,000 RPM (365 RWTQ) but I guess it's possible from what you're saying. It's just a little difficult to understand how but I can accept it (I guess :cry: )

Seems pretty obvious from your experience that what you claim is true unless for some reason your 3rd gen was quite a bit lighter and more aero than your 4th gen.

Well, don't make any decisions yet. I just noticed you are in Aurora. The most power i have seen a stock bottom end lt1 put down is 376 403tq, i think those are the correct numbers. That is from my friends formula with gtp heads, hot cam, etc. You cannot go with the same parts used at sea level. It is a different ball game up here. Smaller cams always yield more hp, small combustion chambers help too while big ones hurt. Etc, Etc. If you really want 400hp, your gonna need a supercharger or one hell of a solid roller setup/heads. Just my .02. btw, you should check out www.coloradof-body.com

Ditto what 94-3.4 said. I put an 8PSI ATI on my SS and the difference between Aurora and Dallas were crazy. Figure 400rwhp at sea level will be about 330rwhp there. Also figure on it lasting longer at that power level.

Mav

well I think superchargers are better than NA, but it depends on what your final goals are and how much money your willing to spend. You will notice many car manufactures going with them these days for good reason. A big cam doesn't idle well, the powerband is raised higher up and of course emissions get worse and gas mileage suffers. Of course either if the two will suffer gas mileage, but I bet the large cam suffers more because you can stay off the boost wheras cam is always gobbling. For the performance of a supercharger you can have great mileage. I read an article of a 96 camaro that passed emissions and made 650 horses with his supercharger. It looks as though your power range is nice and low, which is great for street driving, thats why people are always warned not to go to big with cams cause street driving will suffer. For arguement sake I think heads/cam is cheaper in the long run but supercharger can make so much more power with easy streetability. a 650 horse heads/cam car will have to be very large with high stall and low gears, comparing the two I think supercharger wins with that power level for drivability. I wish they made positive displacement blowers for our cars, that would be the cats meow, having 8 # at 2000 rpm. One company tried but couldn't keep the headgaskets from blowing. check out Skarodoms website it has some dyno charts under "main" and "products" he got 320 rwtq at 2500 rpm and 412 rwhp, so if your making 350 at 2500, I guess your not doing to bad. http://www.advancedinduction.com/

Originally posted by BPS
here you go - the perfect solution
http://web.camaross.com/forums/showthread.php?s=&threadid=71712

No kidding. What a FABULOUS opportunity

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 :D
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.:bow:

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.