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  #16 (permalink)  
Old 08-07-2009, 08:05 PM
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The very first thing you need to invest in is a boost gauge. Until you know how much boost the engine is making you will have a hard time figuring out what's going on with the power. You said the previous owner told you it is 13% underdriven. That iseasy enough to verify as mentioned above. Witha 6-71 on a 350 I would guess your boost is down around 8lbs, based on your drive ratio. You are doing the right thing by asking questions and trying to learn. What you don't know can kill that engine. I highly suggest you buy and read the book "Street Supercharging" by S/A Designs. It will really help you understand what's going on.

Ignition timing and timing curve is very impoortant and will make a major difference in performance and engine cooling.

ISince you don't know all the info on the engine, provide what you can. Verify your drive ratio, check your initial timing and total timing, install a boost gauge and verify boost.

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  #17 (permalink)  
Old 08-09-2009, 04:51 PM
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Thanks again for all everyones help.
I counted the teeth on the pullies and they are 61 snout, and 54 crank.
not sure on the timming or the boost yet, ordered a gauge but won't be here until monday.
the heads are AFR alum. 195 runners, and 68cc.
the trans, is a th 400, with stock converter,
ignition is msd 6 al, coil msd blaster 2, and msd dist.
The rear tires are 295-50-15, bfg radial t/a.
also mentioned is the 456 gear, dual holleys.
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  #18 (permalink)  
Old 08-09-2009, 05:12 PM
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Your 11.5% underdriven. Your biggest problem is the stock torque converter. Car should be scary fast down low with 4.56 gears if the converter and timing is right.
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Old 08-09-2009, 06:16 PM
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Just so my understanding is right. If i put a say, 3000 stall converter in, doesn't that mean that everytime i take off i will be doing 3000 rpm holeshots? almost like a neutral drop at 3000rpm? Sorry for asking such dumb questions, but iam just trying to learn.
Also once i get my boost/vacuum gauge, where do i hook it up to, the intake, or somewhere on the blower?
Is there a pre drilled place, or do i have to drill and install a nipple?
also what oil should i be running in the blower, and how do you check what oil it has, and where to fill it? (i know, its something i should know before even owning a blower engine)
once again sorry for the questions, but iam in new grounds with the high hp engine group. Basic, and mild engines no problem for me, but trying to learn as i go now.

I really do appreciatte any help all you guys are giving me.
Daryl
heres a couple pics of what iam playing with.

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  #20 (permalink)  
Old 08-09-2009, 06:30 PM
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No high stall torque converters do not work like that.
max stall is created only when you go WOT from a standing start. (with high traction tires) (slicks)
If you press the throttle a little, the rpm increases proportionally and you accelerate smoothly. More throttle= more launch rpm and acceleration.
The tach (engine rpm) will be a bit higher during part throttle acceleration than what you are used to with a stock converter.
It will crowd the 2000-2500rpm zone as opposed to the 1200-17000rpm zone during part throttle acceleration you are accustomed to with a stock stall converter.
takes about 1 week of normal driving to get used to the looser part throttle converter coupling. then it becomes natural.
Max WOT converter stall will not be created without racing slicks (traction)

Don;t be a wimp, get a 10" 3500stall converter. When you get it all set up correctly you'll find the 4.56's are a bit more than you need.
3.50's or 3.73's would be just about right for your car with your blown motor.
Get some sticky drag radials too.

Last edited by F-BIRD'88; 08-09-2009 at 06:38 PM.
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Old 08-09-2009, 06:36 PM
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OK, you are misunderstanding how a torque converter works. They are a load and power sensitive power transfer device. The simplest analogy I can offer is that it is similar the centrifugal clutch on a go-kart or mini bike. Just normal putting around or takeoff from a stop a 3000 stall will act just like a stock converter with about 200 rpm more slip, you have to load it up(mash the throttle) to get the stall effect to be apparent. It is nothing like a neutral drop at all, more like slipping a clutch to get areally healthy stickshift to leave a stop light without squealing the tires.

The boost gauge is to be hooked to the manifold below the blower to read pressure, you will have to look to see if there is already a spot for it.

As far as the lube, consult the manufacturer of the blower for type and fill point and oil level.

Sharp looking car!!
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Old 08-09-2009, 06:41 PM
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Nice ride, bud! Here are some perspectives on your questions... others may have a different perspective.

- with a loose (higher stall) converter, you will still feel some pull when you drop it in gear and you will still need to apply some brake pressure at stop lights, but when you mash the loud pedal it will spin up towards the stall rpm as you leave. It won't spin to the stall rpm unless you have a line-lock or trans-brake. You will definitely notice a difference, as the motor is winding into its power band as you leave.

- the boost/vacuum gauge tap comes off the intake manifold below the blower. There should be at least one NPT hole in your intake manifold. If not, drill and tap.

- use gear oil (70-90w) in the blower drive. There should be a filler hole in the front gear plate.
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  #23 (permalink)  
Old 08-10-2009, 08:40 AM
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Kind of hard to suggest a stall speed without knowing the specs on the cam/engine. I would think 2500-3000 should be abour right (I would lean towards 3000). I also agree 4.56 gears are not a good combo for a blown motor unless you are planning to run 1/8 mile. Blowers make a lot of torque down low so you don't need a lot of gear. As mentioned you want the boost gauge connected to the manifold below the blower. Should have a a hole somewhere in the rear of the manifold, probably has a pipe plug in it.

Unless your blower is leaking you shouldn't need to worry about the oil, it can go many many years without needing any attention. Doesn't hurt to check though. There is a pipe plug in the front cover of your blower just to the left of the pulley, that's where you fil it.

Get a timing light on that thing ASAP and see what the initial and total timing is, this can make or break your power output and driveability. With 4.56 gears and stock conveter you should be smoking the tires just off idle.

Keep asking questions that's how you learn.
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  #24 (permalink)  
Old 08-10-2009, 10:05 AM
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I zoomed in on the front cover of the blower in your pictures. There is a little red pushbutton valve on the right (pass side) of the blower snout. You should fill this cover up to the bottom of the hole where this valve is with gear lube. After that there is no need to ever use this pressure releif valve. The front cover will build what ever boost pressure the blower puts out. This helps the lip seals do their job. BDS is pretty emphatic about not relieving this pressure. So don't do it. Fill it and forget it. These blowers are designed to run for years without maintenance.

Otherwise start with a vac/boost gage and set the timing. then have fun.
Nice ride. The blower install looks pretty good. I'm green with envy.

I'm picking up my new blower carbs tomorrow for my new blower set up. Blower should be here next week and the drive the following week.
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  #25 (permalink)  
Old 08-10-2009, 06:34 PM
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Quote:
Originally Posted by bentwings
I zoomed in on the front cover of the blower in your pictures. There is a little red pushbutton valve on the right (pass side) of the blower snout. You should fill this cover up to the bottom of the hole where this valve is with gear lube. After that there is no need to ever use this pressure releif valve. The front cover will build what ever boost pressure the blower puts out. This helps the lip seals do their job. BDS is pretty emphatic about not relieving this pressure. So don't do it. Fill it and forget it. These blowers are designed to run for years without maintenance.

Otherwise start with a vac/boost gage and set the timing. then have fun.
Nice ride. The blower install looks pretty good. I'm green with envy.

I'm picking up my new blower carbs tomorrow for my new blower set up. Blower should be here next week and the drive the following week.
I was looking for the relief valve, but didn't see it until you directed me to it. My blowers have the valve in a slightly different location. I agree the bottom of that hole is the full mark.

Interesting BDS says not to relieve the pressure. Hampton blowers told me to release the pressure when I park the car for the day. I have always done it and never had any issues.
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Old 08-11-2009, 12:41 PM
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Hello again, and really appreciate everyones help with this.
I just got my vac/boost gauge today. I looked on the manifold but only found the pictured fitting. There is one on both sides of the rear of the manifold, but not sure if this is where to hook my gauge up. Looks like it is right on top of part of the head. I drew an arrow to what iam talking about. Please let me know if i can install my fitting for the gauge in this spot.
As for the timming i didn't get a light yet, plus iam unsure of how to check it. Any info on this would be very helpful also.
As for the torque converter would it be a good choice to get the 3000 stall? should it be a 10", is there any thing i need to do to fit a 10" converter, or is it a direct fit?
Thanks again for everyones help, and for your kind comments about my car.

Here is the picture of the intake port iam wondering about for the gauge.

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Old 08-11-2009, 02:49 PM
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Well i had some time to mess around with the car today. The car would never manually shift into 1st, or 2nd gear, only drive. Whenever i would take off out of the hole it would shift so fast that 1st, and 2nd really never did anything, it would be in drive before 20 feet and low rpms. (also no kick down hooked up)
I found that the shifting cable was hooked up wrong, and that the previous owner put a pin in the ratchet shifter so it couldn't be manually put in 1st, or 2nd. I have no idea why, (maybe he was afraid of it lol).
But all i can say now is, this thing came alive now that i can get the rpms up off the line. Its a whole new beast. Now its FUN to drive.
I have put about 200 miles on it in the last 2 weeks and the wow factor was there for the looks, but it wasn't impressing me with the power factor. I can now say i have a smile on my face when i launch it.
I am looking into the websites, and books mentioned as i want to learn all i can, and also with the timing if anyone can break that down for me.
Still unsure of where to hook up the vac/boost gauge also.
Well just wanted to let you guys know the update.
Thanks,
Daryl
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  #28 (permalink)  
Old 08-11-2009, 04:45 PM
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If the transmission has not been modified for full manual/auto shift control with fixed constant transmission internal line pressure (with a "shift kit") then you need to hook up the kick down cable to the throttle. The transmission vacuum modulator should be hooked up as well to the intake manifold below the blower with a inline boost check valve.
The kick down cable controls when the trans will shift and how much line pressure based on throttle input.
The arrow in your pic points to a water port. Don't hook the boost gauge there. Boost must be read off the intake plenum below the supercharger. Some blower intake manifolds are not drilled for vacuum/boost fittings. If yours is not, then you have to remove the blower,remove the intake manifold and drill and tap a hole or two to install fittings.
Look on the passenger side of the manifold at the back below the supercharger.

If you do not know how to operate a advance timing light (after reading the included directions) or how to read the timing tab and adjust spark advance, get a pro to help you that does know how.
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Old 08-11-2009, 06:39 PM
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Thanks for the input. i never checked to see if the vacuum modulator was hooked up. wouldn't it shift hard, (like jolt) when it shifted through the gears if it wasn't? or if not enough vacuum?
I was told the transmission was built up, and had a shift kit installed. but thats words from the previous owner.
It always shifted fine when in drive through 1st, and 2nd, but happened very fast that you were in drive almost immediatly.
As for the kick down, there is no cable installed. with the 456 gears i can't see a need for it, but when i change to 3:50, or 3:73's i may want to hook that up.
I will check again on the manifold for a fitting, but unfortunetly i don't think there is one.
Thanks again for your input.
Daryl
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  #30 (permalink)  
Old 08-11-2009, 07:03 PM
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When it is geared correctly and the kick down is hooked up and properly adjusted it will shift correctly based on throttle load input and rpm.
If the kick down is there but not connected you can assume that the valve body in the trans was not modified to eliminate the need for the kick down.
(fixed trans line pressure) If you want correct auto shifting in D based on how you drive it, then you want to hook up and use the kick down.
Yes that will involve getting creative with a big friggin blower sticking out of the hood. Same with the vacuum modulator. No need to eliminate it just cause you have a blower. Just needs a small 1 way vacuum check valve installed inline.
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