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Discussion Starter #1
Have many books and a ton of magazine articles on power additives from turbo's, superchargers, and nitrous Oxide.

I plan on using a 125-150 HP kit on my build, using forged rods/pistons because I am building for big HP to begin with, but know even cast pistons will be just fine in the 100 HP -125 HP kits.

Nitrous works best on low compression engines, 8.0-9.0 range. It really wakes them up. It would seem to make a lot of sense to me to have a mildly built street 400 CI 0r 455 CI, add the nitrous, and have an engine that will push into the 450-500 HP range with gobs of added torque, at a push of the button.

My question: Any of you have experiences using nitrous on your Pontiac? Again, see it used in magazine cars, but don't know of any actual first hand users with Pontiacs.
 

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BOOM! :seeya​







Seriously though, have an adequate fuel system, do not skimp on wiring, run a hobbs switch on the fuel side, I wouldn't recommend a throttle activated kit, use a manual switch.

Why NOS though? Just build a healthy motor to begin with. You will get tired of filling bottles and it always seems to run out just when you want or need it. And it's like crack, addicting and you'll start to want more and more. Pretty soon you've got two plates and a fogger and you keep telling yourself that those hypereutectic pistons can take a lot of abuse.....:rofl:

I've been there and went supercharged. Just sayin........:seeya:
 

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No real experience with it, but what Alky says. I like power the old fashioned way, all motor and no snakeoil or steroids. I always considered Nitrous the cheater's way to make power.
 

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Discussion Starter #6
X3 :agree
Go turbo, twin turbo or Supercharger.
Ok, sure. Why don't I just skip all the add-ons and go with a Pro-Stock Mountain motor? Obviously some here have deep pockets. :cheers I'm just a po boy maximizing fun and cost in a balancing act that suits my budget. Going lower compression so I can run the "cheap" gas. Running a tunnel ram(going to make it) with dual quads and velocity stacks because to me they look the best. I know, your all rolling your eyes, getting those body tremors, and the corners of your mouths are twitching.......'cause you want to say "No Way, It won't work, Your Nutts." Well, yes I am -nothing new there. HaHa. So don't even go there. Just trust me. HaHa Remember, in theory, Bumble Bees are not supposed to be able to fly. So, I'm just trying "my theory" on how I want to build my engine and not some one else's. Got a few trick's up my sleeve.

Simply wanted to get a couple of Pontiac owners viewpoints on their experiences -preferably street cars and not drag cars. I am not racing my car at the track or trying to best 1/4 mile times. Just looking to use it for what it is, a few seconds burst of power and not a 10 second pass through all 5 speeds.

Personally, if I had the cash, twin turbo would be my pick.
 

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Not bashin' Jim, just giving my opinion. I had a fast street car with NOS and it ended up burning to the ground do to my stupidity.

I just want to caution you on piecing together a setup on the cheap. And definitely have a fire extinguisher and a Hobbs switch on the fuel side. Back in "the day" when me and all my buddies had systems on our cars; every one of us had some sort of catastrophic failure on the juice.And the systems kept getting bigger and bigger. I've seen NOS backfires that literally blew carbs off the manifolds, bent rods and fried pistons.

So when you add it all up as far as a system, all the upgrades necessary to ensure your motor lives and the bottle refills a blower or turbo system isn't really that far off. I picked up my blower with the carbs for under $1K. They are out there.

And I'm definitely not a deep pockets guy, just a gear-head with some grease under his fingernails, some good buds, horsetrading skills and a knack for finding some deals. :cheers
 

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Nitrous can be a great power adder. So can twin turbos. Each require some careful consideration when utilized. Nitrous certainly is quick, easy and way cheaper than twin turbos. I would consult with the nitrous kit supplier and see what they recommend.

Stock cast pistons do not do well with detonation, low compression or not. A lean condition can cause detonation. You will need to spend some $$$ on a fuel system unless you are using a small shot of nitrous.

Not trying to be a wise ass here, but making horsepower takes stronger, well matched parts. Anyone can tack on a huge nitrous system, push the button and go. To keep the engine from going Kaboom and causing you to spend huge amounts of money. I'd talk to the supplier. I'd rather add 50 horsepower reliably than add 150 horsepower and run over engine parts......:mad:
 

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It is your build....... I am with Alky on this one, all the way. My experience was almost identical, put a kit on and man -oh-man that stuff works, give it a lil more and then you want to rip down the road and you run out......bummer, then you want more pressure so you get a bottle warmer and an extra bottle.... and on and on.... then the BACKFIRE that blows the top of the motor part way through the deck lid and then you have melted aluminum manifold shards impregnated into the GLASS. Then just happy that the huge explosion did not do any serious bodily harm other than temporarily ringing in the ears..... long story short.... I would supercharge it, or just build it GOOD. It will cost much less than nos.......
 

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Ok, sure. Why don't I just skip all the add-ons and go with a Pro-Stock Mountain motor? Obviously some here have deep pockets. :cheers I'm just a po boy maximizing fun and cost in a balancing act that suits my budget. Going lower compression so I can run the "cheap" gas. Running a tunnel ram(going to make it) with dual quads and velocity stacks because to me they look the best. I know, your all rolling your eyes, getting those body tremors, and the corners of your mouths are twitching.......'cause you want to say "No Way, It won't work, Your Nutts." Well, yes I am -nothing new there. HaHa. So don't even go there. Just trust me. HaHa Remember, in theory, Bumble Bees are not supposed to be able to fly. So, I'm just trying "my theory" on how I want to build my engine and not some one else's. Got a few trick's up my sleeve.

Simply wanted to get a couple of Pontiac owners viewpoints on their experiences -preferably street cars and not drag cars. I am not racing my car at the track or trying to best 1/4 mile times. Just looking to use it for what it is, a few seconds burst of power and not a 10 second pass through all 5 speeds.

Personally, if I had the cash, twin turbo would be my pick.
You say you're not going to race the car but tunnel rams are made for drag racing and perform like crap on the streets with no/hardly any low end performance. A dual plane is what you want for spirited light to light low end torque and you can get them in a dual 4bbl, just sayin....
 

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Discussion Starter #11
Not bashin' Jim, just giving my opinion. I had a fast street car with NOS and it ended up burning to the ground do to my stupidity.

I just want to caution you on piecing together a setup on the cheap.

ALKY,

Did not take your opinion & advice as "bashing". I want to hear what you have to say. I don't plan on piecing the set-up together. Not going big with it either. I will be doing it right with a separate electric fuel pump/fuel line, fuel pressure shut-off switches, low oil pressure shut-off switch, nitrous ignition timing retard module, etc.. I may spend as much or more on the protection goodies than the nitrous! I know what I am getting into. Superchargers also sneeze back and blow things up and can crack/break the front snout of the crank as well. For me, nitrous "seems" a better choice -I'm not 20 anymore so I won't be using it like I would have 30 years ago. http://www.gtoforum.com/images/smilies/biggrin.gif

For all concerned, again, I don't take any of this personal, so let it fly! My engine will have all the right internals, forged rods, pistons, ARP main & head studs, etc.. Going for a 461-467 CI engine, 450-475 HP range, 500+ ft lbs of torque @ 5,800 RPM. My engine will spin higher, but my cam choice/heads won't really breathe past that. My 5-speed Tremec TKO-600 in factory form is limited to a 6,000 RPM shift UNLESS I fork over another $400 and add carbon fiber bonded synchro's. So in my opinion, I will have plenty of power on tap and built to handle it. The nitrous is just a little extra when some smart acre in a newer high dollar Mustang GT, Chevy Camaro, or Challenger SRT-8 tries to give me a run. That's all its for, just an edge.

I am with everyone on the tunnel ram - yep, its more for drags. However, remember Chrysler had factory long & short tube cross ram manifolds on showroom factory cars that were not for drag racing, but higher horsepower. Of course they did set up drag specific cars using these as well. I don't know of any Desoto drag cars, and yet the option did come on them. The tunnel ram is more RPM specific, and generally upper RPM's. Since I will be making my own, or at least making an attempt to, I have a specific design in mind that I want to experiment with and try. You all know that Pontiac had the bathtub tunnel ram on the SD-421's and Wenzler offers a contemporary tunnel ram that is said to be street friendly. Of course Mickey Thompson made a cross ram as well. If my "experimental" intake fails, then there is always the Edelbrock or Offenhouser 2 x 4 intake. (did I tell you that I have an experimental factory cast iron 1956 Pontiac 2 x 4 intake?). Dual quads will be used on my engine in one form or another. I like the tunnel ram look, but will take a low rise. Back in "the day", many cars were modified with tunnel rams on the street, especially those Mopar boys. They ran pretty good in street cars in my area. I feel the key is the camshaft selection with matching parts for proper air flow.

I think I have a pretty good handle on what I want and how to get it. I have the VFN one piece 1969 GTO fiberglass nose, no hood, so as to have an open engine and lighten the front end. It will be tilt. Disc brake conversion. TKO-600 5 speed & bullet proof 9" Ford rear with a locker and 3.70 gearing. Going high in stance using tall El Camino front springs with a bit higher in the rear. Front & rear sway bars. Installing an 8-point roll bar in the sparse 2-seat interior, and the Hoosier M-50's (or like) on 10 inch steel Nascar style blacked out rims hanging out the wheel wells (8 in up front) should give it a street racer look -which is what I am after. Zoomie exhaust pipes exiting in front of the rear tires. Paint will be semi-gloss black, shaved door handles, blacked out trim, silver tint glass, rear window louvers, rear spoiler, fiberglass rear bumper. Probably add a 1970 Judge front chin spoiler, and may install a front pushbar/brush guard ie Duke's of Hazzard. Select chrome emblems. But, I am not building it as a drag car, although I certainly can drag race it. It won't be your average car resto or resto-mod. Going for a personalized look that suites me. I want something that looks badass standing still, and when I fire it up, well..........Giddy-up. That's my vision and I'm sticking to it.http://www.gtoforum.com/images/smilies/smile.gif
 

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sounds like a modern day Mad Max Interceptor, should be cool. I am getting ready to put dual 600 holleys on a Offy manifold on the Tempest, all under the hood with a custom RA pan and GTO hood. waiting til after the cruise season so i dont have any downtime tweaking it. Next 5 weekends are all major cruises here in The Motor City, culminated by the biggest car event in the world "Woodward Dream Cruise". Do not want to get stuck in that 20 mile line overheated.
 

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Discussion Starter #14
I built a model, many years ago, of exactly what I pictured as the design/mods I would like. I also had the long ladder bars that went from the rear axle to the transmission crossmember. The model is long gone, but the image is not. I would have liked to have chopped the top a few inches or laid back the windshield, but the roof lines just don't support such a mod. I have seen a few photos of it done, and it just doesn't proportion right. If it had been a '65-'67 car then I would have done it. There is a '67 Chevelle I see every year at a car show that has this done and with the high stance of the car, it looks great -like an old T-shirt cartoon type car.

Yep, it does sorta look like the Punisher car, or a spin on it. Even thought about a Mad Max look as well, grafting & modifying a late '70's Firebird/Trans-Am high slant endura bumper to the front and adding headlight covers, roof spoiler, bolt on fender flares made for a pickup or 4 wheel drive, rear window delete, and a couple 55 gal drums in the back as my gas tanks. Even figured on the "fake" blower set-up. But decided to go with what I am building towards now.

I uploaded 2 pics of the 1969 fiberglass nose (hope I did this right). My car is '68 so I will do some fiberglass work to fit my corner lights in it and convert to LED lighting. My rear bumper will incorporate LED lights as well. I found a camper supply store that has LED replacement stop lights that plug into the old "1157" filament bulb sockets onto the original '68, and they appear to be large and wide enough to fill the space where the factory lenses go (you can see this type on most modern school buses). I will put white LED lights in the middle of two of these red LED's to act as my backup lights. I will also be adding a third brake light on the rear package shelf like modern cars have.

Figured as I begin to do my build, I will post pics -may help some people. Pulling the body off the chassis to do all this. Figuring on boxing/adding an inside rail stiffener to the frame rails like a convertible to give it more rigidity and probably solid body mount bushings, although those poly bushings may be solid enough.

Just having fun with it and who knows what the "final" look will be, but I have a plan at least. Gathering parts first, then I'll tackle the build.
 

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Discussion Starter #15
Instg8ter - "I am getting ready to put dual 600 holleys on a Offy manifold on the Tempest, all under the hood with a custom RA pan and GTO hood."




When I had my '67 GTO, an acquaintance had a '66 GTO with 389 and the Offy duals with AFB carbs. It went pretty good. I could have bought it, but the car was rough and priced to high.

I have never ran any Holley's except a new 800 CFM spreadbore that did not prove to work as good as the 2 x 4's I used it to replace. I put back the 2 x 4's after about a month. I still have an original factory numbered 1969 Chevelle 375 HP 780 Holley in good shape. The old 780's were a hot set-up in the day. When I was into the Chevy 409's, I purchased a Weiand 440 CI tunnel ram and a pair of race 660 center squirters modified with bigger (I believe) 780 bases. You can mill down the Weiand, mill a factory 409 aluminum intake, and fit them together and weld them up. The ports line up. I was building a 482 CI stroker motor -427 CI steel crank machined to fit the 409, forged steel 7/16 "dimple" rods all prepped, Jahns pistons, and a lot of machine work. Had all the top end parts as well. But, as usual, one thing led to another and all were sold off -long story.

I prefer the AFB carbs over Holley for duals -just personal preference. I bought a pair of Edelbrock 750 AFB's off Ebay for my '68 build. Got to rebuild them. Used a pair of AFB's that came off a 1966-1967 Lincoln 460 CI on my 409. They ran a little rich as I never jetted them, but they ran great. That engine pulled as hard as I dared to redline it with no sign of letting up. Factory forged crank & rods, but heavy cast pistons. 6,200 RPM was no problem but trying to get to 6,500 usually resulted in the outer valve spring breaking. The inner spring would save the valve from dropping. Did that twice, so I set my rev limiter/tach to 6,2000 and never had any problems.

Post us on your progress and experience through all this. Let us know how the "seat of the pants" feel is in comparison to what you have now -should be interesting.
 

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Discussion Starter #17
Have a 750 AFB Eddy on it right now, runs ok but i am pushing a 2:56 rear end at the moment. Have a 12 bolt with 3:55 sitting in the shop, that will probably go on it with the dual set-up. Was nice getting 16.5 MPG freeway with a 473...LOL, so much for that.

Heres a link to the thread Jim

http://www.gtoforum.com/f50/67-tripower-ra-pan-48242/

I checked it out, looks cool. 2:56's are pretty stiff. Big HP/torque and those gears makes for some good burnouts! 3:55's will give more acceleration, and yep, this and the 2 x 4's are going to kill your gas mileage. My 409CI with the AFB carbs in the Impala got 8MPG's on a "fun" day and 12MPG's when I drove it like an egg was under the gas pedal -but then it would load up and run like crap, and of course I would have to blow it out, right? I ran a posi 1967 Olds full size rear that I fitted under it which was more like a Dana in size. It was 3.08's which I had no problem pulling with all the HP. Top end was way past the handling of the car as the big car got real light heading up past 120 MPH. I had my take-off down to a science. I think I dumped the clutch at about 2,000 RPM, the M-50's would spin one revolution with a chirp, and then I would nail it, and off it would go. Higher RPM take-off's only caused that old familiar violent wheel hop. I don't recall any of my Pontiacs having that problem, but they also didn't have that power, the wide tires, or posi -tires would just spin and smoke.
 
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