anyone out there running this kind of set up? if so have you got it to hook with out tubing the car? im about to put my new engin in the car . im going to do mu bet to set the car up so that i dont have to cut up the back end. ill be running around 8 lbs of boost on the street and around 12 at the track . street slicks on the street and drag slicks at the track.

I run a 496 N/A, and yours with boost will be a handfull.

i hope so lmfao graemlins/hurray.gif

Only a properly equipped racing chassis set up
will be able to use this combo.Maybe coil spring
rearend with ladder and anti-roll bars anyway.
Anything less will probably wheel hop and/or smoke
the tires.Sounds like my cup of tea though! graemlins/beers.gif

At least it will look and sound good. you can win burnout contests too.

doggy this is BAD72SS from the street racing board

As I'm reading this I'm hoping that your next post isn't going to be something like "will this make enough torque - or do I need to go bigger?".

And to think, in another post you were fretting about weakening your quarter panels by rolling the lip to clear a wider tire.

On the other hand I like it when someone goes to excess under the hood, apparently unaware of what traction issues awaits them.

An 8-71 will build tremendous down low torque, greatly exaggerated by the 4.25 stroke. On a centrifugally supercharged 468, which makes less low rpm boost vs your 8-71, I made 600 tq by 3,000 rpm (peak torque was 863!). On my n/a pump gas 496 I made 495 tq as low as 2,500 rpm. I made my maiden passes with the 496 last weekend. With sucky 1.8ish 60's it ran 11.3x's - I hope to work a few details out to get my '60's in the 1.5ish range, and e.t.'s in the upper 10's.

Eric, your 8-71 496 will make unbelievable low end torque - way beyond what I have.

Rolling your wheelwells will be the least of your issues, the full cage and net had better be in your plans if you plan on making more than one pass at the dragstrip. Tubing it and back-halfing it would be a great idea.

Thomas

No ****...lol though the idea sounded familiar....lol. Now I know you combo. Everyone told me I needed to backhalf my car I said no bc I wanted a back seat. Unfortuantely for what you want you'll need to. Or you could try the ssm liftbars brag shocks and springs and lessen the front end weight. Should be interesting to see.

i dont remember posting about rolled wheel wells. also the cam i had made by isky should be on the slugish side out of the hole and pull hard up top. trust me i have been doing my home work on this. i know hooking will be hard and if i cant get it to hook . then ill put it in another car . at another time. but i have to try its the only real way to learn . people can say it cant be done .but untill you try it for your self you can truly never belive

Oops, it was not you on the rolling of the rear wheelwells, that was 406_Chevelle, another TC'er with a '72.

Now I like this whole Don Quixote thing, where you want to go down an unconventional path and prove your ideas to everyone.

I gotta tell you most likely any cam profile that will kill a blower engines bottom end power will also kill upper end power. I would be very interested to see how you can bleed off low rpm cylinder pressure, yet keep most cylinder pressure in the upper rpms. This can, and has, been done countless times with n/a engines - but an engine under boost breaths much differently.

Okay, I rethought this and I think I have an idea for you: Normally a supercharged engine is run with low compression and a cam profile that keeps cylinder pressure up. How about you build it with two full points more compression ratio than a blower engine, in the 10+ range instead of in the 8ish range. Then run a n/a cam profile with much more overlap than a blower cam.

Thomas

i have to put my trust in the cam company that they know what they are doing .

I'm running a 6-71 on a 470ci, tubbed, 4-link, and there's no hooking on the street (granted, my M/T's aren't sticky at all). The motor makes so much low and mid range torque that I don't forsee it hooking at all on the street, regardless of tires, and on the track, well, good slicks would do it, along with good chassis tuning.

You might be able to get some of the power to the pavement with 9 or 10" slicks, but you're gonna have to be mellow out of the hole.

Originally posted by chevelleracer:
i have to put my trust in the cam company that they know what they are doing . Eric,
I have the utmost respect for Isky & am a WD for them but trust me when I tell you Thomas is right.
With 500 inches & a roots blower as soon as you open the throttle you are going to have instant torque regardless of what cam you put in it. :D
If you have ever seen the torque curve on a roots type blower you would know what I refer to.
It goes damn near straight up from the point where the throttle is opened.

i know i had a small 177 super charger on the car once befor. i know its going to want to blow the tires off. but im willing to see what i can get the car to do . i hope to have it going by the end of the summer when i do ill keep you guys updated

I'm gonna say that you are well on your way to becoming a "true believer". While you are out there testing your hot rod beliefs and dogma I have a request: could you also do some tests with nitro methane? I want to know if everything they say about it is true :D

I like this guy. Its not enough for him to hear what others who have played with blowers have to say - noooo, he has to prove it for himself.

Rock on brother, and get your best asphalt dancing shoes ready - because you are going to need them to keep your dancing partner within the curb to curb of the asphalt playground.

Thomas

IMO it wouldnt hook in a towtruck. What size slicks you planning on running? Dont think it'll matter. You need vht sprayer in you rear fenders :D

doggy youll be on my short list of cars to send home. graemlins/thumbsup.gif for that remark :D

Send me home never said you couldnt but right now you cant. I was being dead serious you'll just keep spinning

:D :D :D i know i will on the street

Your 454 still together..wanna get one off?

no its not. BUT!!!! i may be putting my 402 back in for a little.

pm me if ya throw it back in....Im going to florida at the end of august

hey Racer what are your plans on fuel delivery and cooling for the big rat?

These guys are right, you will never get a dead hook on the street without tubbing your ride. I've found that a large Drag Radial is a nice compromise for street traction. They are safer than regular radial tires and handle a whole lot better than a M/T DOT slick. You're going to have a handful of fun when finished. graemlins/beers.gif

I KNOW IT WONT HOOK ON THE STREET :D . i know im going to have a hell of a time getting it to hook at the track. as for fuel . i have yet to settle on a pump for the car but the tank is sumped and ill be runing 1/2 inch line.as for carbs. i havent decided yet eather. most likely 2 750hp's or 950hp's . i dont like demons. ill be running pump gas with areound 7-8lbs of boost and when i change the pullys to run 12+ lbs ill be running race gas.lucky for me tires are better now then 10 years ago let alone 20

wes have you run your car at the track yet?what kind of front springs and shocks are you running.

No track time yet so I can't give you any ideas on what ET's you could expect. Staying right at 500ci, I'd suggest two Holley HP 750's, which will also have manifold referenced power valves. BDS recommends using more carburator CFM (950cfm) with 540ci and up.

Since you are in the market for a fuel pump, I'd suggest an Aeromotive A1000 unit. I've had zero issues with mine after nearly 2 years of hard street use. One other suggestion I can offer is to NOT use too small of a fuel filter in your plumbing system. The fuel demand of a blower motor will find your plumbing system 'bottleneck' or weak spot in a hurry. Hope this helps some.

thanks. what blower is on your car? with or with out teflon strip?

It's a BDS 8-71, stage 1, street blower without Teflon strips on the rotors. I recall asking about the Teflon strips and I'm going by memory here, but I think once you start pushing more than 15lbs of boost thru the blower, then you need to consider using the Teflon strips on the rotors. Otherwise, it's overkill and not needed for most street applications.

Forgot the other part of your earlier question...I'm using factory BB springs with 1/2 of a full coil removed from both, and the shocks are KYB units.

thanks. are you running pwer stearing ? if so what brakets are you useing

Colby's setup as per his site
Peak Horsepower 791 @ 6,000 rpm's
Peak Torque 780 ftlbs. @ 4,600 rpm's
Dyno Run Conditions: 93 octane pump gas with 6.5lbs of boost

Power Plant:
* Owens Racing built 502ci Gen VI Blown Big Block
* Polished BDS 8-71 Blower, 8mm pulleys, 4.5lbs of 'pump friendly' boost, underdriven
* 8.6 - 1 compression
* GM Performance Parts forged rotating assembly
* GM Performance Parts 290cc aluminum heads
* 2.25" intake valves and 1.88" exhaust valves
* Lunati Hydraulic Roller Camshaft
* 245 intake - 250 exhaust duration @ .050 lift
* .648 intake .648 exhaust lift
* LSA of 114 degrees

Fuel Delivery:
* Twin Holley 750HP blower carburators, 76 primary and 87 secondary jets
* 10.5" high-flow power valves
* Aeromotive 100 micron billet fuel filter
* Aeromotive A1000 fuel pump
* RCI trunk mounted pro-street fuel cell
* #8 braided fuel lines
* System1 Pro-street billet fuel filter
* Aeromotive A1000 pressure regulator

Transmission and Driveline:
* Mike Kurtz custom built 200R4 GN overdrive transmisson
* Circle D 10" 2,800 RPM converter
* Custom balanced, steel driveshaft
* 1330 Spicer u-joints
* Lakewood driveshaft safety loop

Rear-end Configuration:
* 12-bolt posi prepared by Tom's Differentials
* 4.10 gear
* 33 spline axles
* Eaton 'Stage 5' modified carrier
* aluminum rear-end support cover

Exhaust:
* 2" x 3.5" coated Hooker SuperComp hedders
* 3.5" Torque Tech exhaust system
* DynoMax 5" bullet mufflers

Brakes:
* Wilwood Dynalite front disk brakes
* Rear drum brakes with Praise Dyno shoes
* '67 Corvette manual disc/disc master cylinder

Cooling:
* Griffin two row aluminum radiator
* G.M. HighFlo aluminum water pump
* Twin 13" BeCool electric fans
* Zoops billet brackets and v-belt pulleys

Ignition:
* MSD Digital 6+ firebox
* MSD 6,400 rpm rev limiter
* MSD billet distributor
* MSD Blaster HVC coil
* East Coast Electronics 1-wire 110amp alternator
* Taylor 409 Spiral Core 10.4 mm wires

Wheels, Tires and Suspension
* Front Wheels: 15X7 Monocoque RT billet wheels, 4.5" backspacing
* Front Tires: 225-60-15 B.F.Goodrich Radial TA
* Rear Wheels: 15X10 Monocoque RT billet wheels, 5.75" backspacing
* Rear Tires: 325-50-15 B.F.Goodrich Drag Radial
* Polygraphite bushings throughout suspension and at body mounts
* Front 1.25" sway bar
* Rear 1.00" sway bar
* SSM rear lower control arms
* KYB shocks on all four corners
* Stock front and rear coil springs

Originally posted by Wes Colby:
No track time yet so I can't give you any ideas on what ET's you could expect. Staying right at 500ci, I'd suggest two Holley HP 750's, which will also have manifold referenced power valves. BDS recommends using more carburator CFM (950cfm) with 540ci and up.

Since you are in the market for a fuel pump, I'd suggest an Aeromotive A1000 unit. I've had zero issues with mine after nearly 2 years of hard street use. One other suggestion I can offer is to NOT use too small of a fuel filter in your plumbing system. The fuel demand of a blower motor will find your plumbing system 'bottleneck' or weak spot in a hurry. Hope this helps some. Wes,

How do you have your hook up for the "manifold reference" setup? I was looking at your pics and don't see it graemlins/clonk.gif Also are you running the boost reference from the regulator too?

Chevelleracer, the power steering kit I used is a remote resorvoir style manufactured by Zoops. It's worked very well with no issues to speak of. I'm not sure if my website has a pic of that set-up though.

Hey Jeff, the manifold referenced PV's are getting their signal from two of the vacuum ports on the lower rear of the blower intake manifold. From there, I run two very small vacuum hoses up to each of the male vacuum ports for each carb.

The vacuum port often seen on fuel pressure regulators (I've got mine capped off at the regulator) are designed to work with blow-through style superchargers, like a Paxton. I thought the same thing when I first read the instructions that came with the regulator until Craig over at BDS cleared it up for me.

When you get a chance Jeff, let me know more details on the '70 you are building up...email me when you can. Are you putting an 8-71 on top of the 540? graemlins/thumbsup.gif

chevelleracer, here's some more data from my motor combo.

I'm running 90/10's in front with big block springs.

My motor is extremely close to Wes' motor in terms of build, he's got 30 more cubes (I'm right around 470ci), but as far as the rest of the motor goes, it's very similar. I run a 6-71, 7psi (teflon'd for longevity), 8.75:1, and Holley 750's that were built for this motor by the Carb Shop. Differences between my setup and Wes' are that I'm running a Vertex magneto, a little longer duration cam (270/280 @ 0.050, 114LSA) but about the same lift. Drive-train wise I'm running a T400 and a 4500 stall converter, 9" Ford, 4.56's. The car is backhalved. I haven't had it to the strip with this motor combo, but the old combo did 10's with traction problems. This motor is significantly more bawlsy and I expect it should do very, very low 10's in it's current state and 9.90 with traction. If I can ever get it to the track with some good tires then we can really see smile.gif

We're all waiting for Jeff (ACE841) to get his blown 540 on the road, that should be quite the monster. graemlins/thumbsup.gif

i should have my engine back next week. ill post the complet set up then. i cant remember tall the cam specs. off the top of my head the engine biulder has all my paper work. i normaly assamble my own engines but since this is my first blower engine i figered i pay someone that biulds them for a living. but im running a 1990 ss454 4bolt block . steel crank h-beam rods jw blower pistons. solid roller cam moroso kick out pan with trap door and windage screen. moroso oil pump.bowtie alum sqare port heads that have alot of work done to them.stud girdles. main studs head studs. pro magnum roller rockers.comp cam rooler lifters.milodon gear drive. 8-71 teflon striped blower from the blower shop. 36 tooth top and bottom for 1:1 .the block is half filled to the freeze plugs. 0 gap rings