[transam_101]

Hi all,

I have a 78 Pontiac T/A and I'm getting ready to order a Pontiac 535 stroker once I have my new TH400/Gearvendors OD/Moser rear setup installed. I've been through the compression calculations many times and have had multiple conversations with the builder. But I keep going back and forth between the decision to order a 10.8:1 compression setup, (w/ worked 340 CFM heads and 1000 cfm carb = ~700hp ) OR that of an 8.5:1 compression setup with a dyer's blowers 871 (possibly even a centrifugal setup) = ~800+hp. The drivetrain I have at the ready should be able to withstand the torque numbers.

So before I can even start to spec out cams, torque converters, etc... is that I need to know what direction I should be taking the motor? Naturally asperated or forced induction (supercharged in my preference)? The car is a weekend warrior by my definition. Occasional test and tune drag weekends, but largely just a nice weekend about town regressing to my stupid teenage years (this time with some guts to backup the loud the exhaust).

That being said, any advice from people that have crossed this decision making point? Anyone ordered a motor built for N/A only to wish they had less compression for a power adder later on? Vice versa?

I would like to keep that nostalgic shaker hood, but I think it would be worth the sacrifice in the end...

Thoughts?
-TA101

 

[Moosecountry]

big wallet or small wallet? 10 second street car is a hand full

 

[cerial]

Blowers are more for looks at this point.

You can size a turbo to spool when you want it to and make more boost using less horsepower then a supercharger.

I am a fan of a NA setup. Get it tuned to run on whatever fuel you decide to use and your done. Less messing around with all the extra stuff (to keep from melting things) that comes with forced induction.

I had a 78 also. No T tops though. The shaker is a fun thing to have. But if I needed to bolt on dual carbs I would have not hesitated to pull it.
I got in more trouble with a 80 Firebird with a 383 then I did in the 78. But they were both fun cars.

 

[ogre]

Thoughts?
-TA101

it's a sad fact of life, unless your wallet is huge, with a 535 you won't drive it much.
guy wants a blown stroked bbc, spends half of his retirement on it, ends up never driving it
what was a fun sbc cruiser turns into a money sucking monster
yes i know this is hotrodders.com

 

[transam_101]

it's a sad fact of life, unless your wallet is huge, with a 535 you won't drive it much.
guy wants a blown stroked bbc, spends half of his retirement on it, ends up never driving it
what was a fun sbc cruiser turns into a money sucking monster
yes i know this is hotrodders.com

So are you saying this from a fuel usage perspective, drivability standpoint, other? I don't want to get too hung up on the cost factor of things. It will ALWAYS be an expensive hobby...

I would be concerned if you say it would no longer be 'fun' and just become a 'bother' to take for a spin though which is why I'd like you to expand on that thought.

 

[cerial]

I have had weekend rides that ranged between 4 and 6mpg. The only annoyance is the fact your adding fuel to the tank every time you drive it.
I never cared what gas has cost. I planned on it being over $6 at this point.

The issue with a supercharger is that you need to be xareful with what you feed and play on the safe side or run a good amount of electronics because the air density can change throughout the day.
I know around here a 40 or even 50 degree swing is possible meaning your boost levels may change. While you tune remains fixed. Electronics can help here.

 

[ogre]

800+ hp in a weekend warrior for around town cruising...
you'll go the same speed as my 58 with 350 hp and spend more on the motor than i have in my 58truk. it's just that i see it all the time, you have a nice streetable car, it's fun to drive and hang out at cruise-ins with the friends. then you go add 500 hp, now it always need an adjustment to start, another one to run, another one to turn it off, it's not very streetable, it overheats on hot days, it will suck your very soul just to go to a cruise-in.
yes, this is hotrodders.com, but why take a fun cruiser and mess with it? if you were gonna drag race or do hot rod drag week for a couple years, go for it, better go more than 800 hp. but for around town cruising? keep it fun, my truk will do endless tire roasting, i recoat my driveway every year with rubber. it's not cool to do burnouts at any event.

 

[lmsport]

if you have nothing, going with an LS.

guys with a beat up 5.3 and a $2000 turbo kit are making 650hp, and driving them daily.

 

[transam_101]

Agreed, I did take a strong look at the LS platform, but something just feels right to keep it a Pontiac block (even though the IA2 block is just Pontiac by architecture name only). I have the original 400 block, ported ~340cfm alum. edelbrock 72cc heads, dougs headers, and crappy edelbrock pro flo 3 setup in it today. When the EFI decides it's going to work, it runs great. But it's just seems it's more growl than 'go'. Hence I could swap my current heads/headers onto the IA2 block and really have some fun. So there is that element of parts reuse as it comes to saving a few bucks. But again, don't want this to turn into a cost discussion.

Everything I read about the butler IA2 builds (either N/A or forced) lends itself to being a very 'street-able' setup at this power range if you don't over do the cam. Now admittedly, I have very little practical experience with a super/turbo charged setups. But there is plenty of reading out there for the computer input controlled ignitions as it stands to the outside environmentals to overcome the differences mentioned by Cerial. Sorry, I guess I'm just having a hard time deciding and not sure what questions to ask other than overall group preference. It all comes down to the desired compression ratio when ordering the rotating assembly.

 

[lmsport]

Fueltech is ECU you want to use.

 

[cerial]

Run NA and e85. Tune it once on the safe side and you will be done. I would run a efi setup of some sort which will maintain driveablity by being able to adjust for things.

If you want to maintain the look then aftermarket TBI may be up to the task.

If you care about performance a 8 pack port injection efi setup looks cool on any motor.

 

[nyceguy01]

Yeah, I cant count the number of times at cars and coffee Ive heard guys say " I wish I hadnt used that big blower" or the super popular " I wish I had 100 or 200 less horsepower " ...lol
In a toy .. Yes you want the big blower. Will a 10-71 fit ?

 

[Ianstaine1]

I'm building a car for virtually the same reason.. Weekend Cruiser and half a dozen test and tunes a year.. if that... What i did is Run around 9-1 comp and run EFI.. In my case, Holley Sniper.. and then you can run a Dry NOS system and it is programmable in the ECU, you can also program timing curves etc. This gives you the streetability of a 500-600 hp Fuel Injected Street Engine and still have more power on Tap. I also don't want to have a Full Roll Cage but more likely a roll bar which keeps me in the 10.49 - 11.49 range anyway. Just a thought, i was in a similar boat as you where my Budget was pretty high but i figured this setup was the most Effective Strategy.

 

[64nailhead]

This thread describes every reason to run a turbo.

Turbo means mild cam and 350-500na HP. Gear it run for mileage, i.e a TH400 with sub 3.50 gears and a 26-28" tire. Very streetable so far, then add 12-20psi of boost and run low 9's at the track. Whether you go EFI or a blow through carb doesn't matter. I see absolutely no reason to go centrifugal blower other than for eye candy.

You can build a stock 455BBP with quality parts and machine work and then add 10 psi and make 700hp with a streetable cam. You could even bury the turbo in the truck and let everyone think you have a sweet NA ride. unless they look hard. And better yet, you could build a 9:1 BBP that makes 350hp due to the 'just above stock cam ' specs and chuck 20 PSI at it and make 800hp safe, reliably and with good fuel economy.

 

[cerial]

Yeah, I cant count the number of times at cars and coffee Ive heard guys say " I wish I hadnt used that big blower" or the super popular " I wish I had 100 or 200 less horsepower " ...lol
In a toy .. Yes you want the big blower. Will a 10-71 fit ?

When you start breaking parts on a regular basis or need to replace a clutch/clutch pack that cost 2 or even 3 times what the one that would handle 100 or 200hp less would cost you will look back and ask yourself if you really need that 100 or 200hp.

Some my rides that I had the most fun in had less then 250hp. Not much of the original car left due to weight reduction. But a horsepower number is just that. A number. How you use that horsepower is what matters.
You can have 700hp. If you spend 80feet of it spinning your tires then that's to much and you need to de tune the thing so that it hooks with only 500 or even 450.

Blowers are for looks. If you want a supercharger then a vortec style can give you the performance curve while saving on weight/clearance.

Turbo's were not really a cheap/easy to find thing in the 70's. But a 871 could be pulled off of a diesel at a yard and fitted rather easily to make boost. That is why they were ran into the 80's. Turbo lag kept them around through the 90's. But by 2000 enough turbo's were becoming cheap/easy to find that the roots style was becoming outdated. Now 20 years later turbo's are even more widly available letting you control exactly when you make boost with a curve that can mimic a supercharger's curve. The electronics to run them have become much better letting you run higher boost levels safey. You can do the same thing with a supercharger. But not at the same levels as a turbo without more work.

I had a ssei bonneville with a supercharged 3800. I played around with that thing and made some ok numbers running 10 psi. But I pulled the supercharger off and fitted a aluminum plenum onto the thing running a single turbo running 16 psi and the difference was night and day. I had 4 good runs before I destroyed that junk fwd transmission.
I have not run a supercharger since.

That was in a heavy fwd car which is frankly what killed me running it further more then anything. The weight thing is your biggest issue here. If you can reduce the weight and move the weight around you do have then you do not need stupid high horsepower that will be a headache to make streetable. You can be running 10's with 400 horsepower and daily drive the thing. It just comes down to how much of the original car you want left. Some times switching platforms is the easiest way to reduce weight. But if you get creative I am sure you can drop some serious weight on that old girl.

 

[ogre]

Yeah, I cant count the number of times at cars and coffee Ive heard guys say " I wish I hadnt used that big blower" or the super popular " I wish I had 100 or 200 less horsepower " ...lol
In a toy .. Yes you want the big blower. Will a 10-71 fit ?

maybe not, but i see those guys driving their dd to cars and coffee, cuz the 800hp classic is in the garage

 

[nyceguy01]

maybe not, but i see those guys driving their dd to cars and coffee, cuz the 800hp classic is in the garage

Those guys are lame...lol I get having a cool cruiser but for me the fun of a hotrod is too much power, too much cam, and of course two bald rear tires...

 

[ogre]

Those guys are lame...lol I get having a cool cruiser but for me the fun of a hotrod is too much power, too much cam, and of course two bald rear tires...

i have to ask... what big hp hotrod do you run, nyceguy? how many miles do you drive it yearly?
transam want it for occasional test n tune, probably not a track with 200 miles of him for test n tune.
i'm just saying, don't exchange a cool cruiser for the monster you never let out
i drove truk 6000 miles/yr until recently, my handicap is messing with me

 

[nyceguy01]

Just a couple old Chevy trucks. One with a stout small block and one with a decent 496 big block.(700 ish hp)
I probably put around 5000 miles on them ( Combined ) a year. Neither is very good for long road trips but are a hoot around town etc...
They closed our local track a couple years ago so I have to travel several hours for a drag strip these days. They did just start doing some roll racing an hour away, Ill gove that a try this summer for sure..

I certainly wouldnt want a big blower or the cams Im running in something I need to use to get to work or road trip but for how I use them and what is a "hotrod" in my mind I think I wouldnt have it any other way. If Power tour comes out west again Ill change the rear gears and road trip it though lol...

 

[topfuel]

One thing that no one can argue with, a big polished blower draws attention, and isn't that why we build our hot rods? I went from a tunnel ram set up with nitrous and a 4.56 gear in the rear to a 10-71 blower and 3.73 gears. It draws more attention, makes the same of slightly more horsepower and is more streetable with the change in gearing. This has been my street car for 30 years and the switch to the blower set up was the best change I've ever made to the car. You will never draw the attention with a turbo that you will with a big, polished blower sticking up through the hood.