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I'm officially Banks TT! Recommend Stall Please.


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I bought the kit today off EBAY, you all may have seen it. TT blow through with everything for $3500, should be here this week. Going to buy the cam, sending the C&S 800 back to be modified for blow through application, buying a alcohol boost referenced FPR, then it's just down to getting it installed on the engine, getting a custom converter built and getting the whole mess installed in something with wheels.

 

Question: What stall converter to get? Cam pulls from 3500 to 6500, but I don't know just what to get for stall, suggestions. I'm afraid of getting too much stall that the transbrake won't hold all the TQ, but I want enough to get it all moving without smoking the tires. The z is so light that I was thinking of just getting a blower type converter at 2500 stall. The PG is built for 900HP in the high drum and will hold 700 in the reverse clutch pack, has new turbo splined input shaft, BTE race pump, kevlar band and is on the tight side clearance wise throughout.

 

Also rear gears, what ratio? Got 4.11's, but was thinking of going to 2.73's or something of that sort. Experience chime in anytime. Expecting the z to post some wicked times and insane MPH in the quarter.

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You did not give the info needed to help determine what might work for you. Estimated HP, redline, tire diameter & weight with driver. My car weighed in at 2,750# w/me and I ran a 27x11.5 QTP so I used those and assume the engine will make 600rwhp and that the car will go 9.70 @ 142. The big unknown is the converter slip and I am assuming 10%. Probably off on the assumptions but at least you might be able to use this in other calculations.

 

Based on that timeslip and 10% slip, here are some estimates for trap speed RPM @ 142mph for different gear ratios:

 

2.73 - 5,430 (10% slip makes it more like 3.00)

3.07 - 6,105 (10% slip makes it more like 3.38 )

4.11 - 8,175 (10% slip makes it more like 4.52)

 

Of course, the taller the gear and/or tire, the higher the MPH and the shorter the gear and/or tire or worse the converter slip, you get less MPH, but I used a constant MPH for all to make it easier.

 

As for the stall, its a sure bet you will not get it right the first time, so make sure the converter maker offeres a free restall once you find out what will actually work. Not sure you need to worry about the transbrake. Remember how a transbrake works - it puts the tranny in both reverse and first at the same time and releases reverse when you launch. Your best bet is to work with the converter maker and try to be as accurate as possible with estimated HP/torque, cam specs and turbo specs, especially the turbine side as that is what affects spoolup most.

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Also rear gears, what ratio? Got 4.11's, but was thinking of going to 2.73's or something of that sort. Experience chime in anytime. Expecting the z to post some wicked times and insane MPH in the quarter.

 

The answers to your questions depend on the RPM your turbos are designed to spool up. My converter stalls between 3500 and 3800 rpm. My turbos are fully spooled up at 4500 RPM. But I don't want a higher stall converter because I still drive the Z on the street. You don't have that limitation, so you can go higher. I still lose traction at launch with this set-up.

 

If your turbos spool early then you better have a tight converter. In that case there will be less top end slip and you can use a 4.11 ratio. I have that with a 29" tall tire and go through the 1/4 mile lights at 6500 RPM or higher. My cam is in the same RPM range as yours. and as Scottie said your transbrake will hold the power.

I ran at Fontana drags last week and ran 10.20's at 115 mph after braking at the 1200 foot mark, so I wouldn't get kicked out again.

 

But if they spool up at a higher RPM and you have a tight converter, you might bog at launch due to the turbo lag. But then how could anyone bog with a 13:1 compression engine on alcohol?:shock:

 

Lets face it you are building an "animal" and you better first attach wheely bars and a parachute before you take it on its first run. I'm waiting for pics.

Hanns

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Thanks Hanns and scottie. The car weighs 2750 with my lard butt in in it. The tires I run are 29.5x9x15's. Then engine will redline at 6500 rpm. Banks says at 12psi it should be making 800+HP and 600+TQ on alcohol, we'll see. The system is capable of 20psi boost which according to them would be 1200+HP and over 900+TQ which would be insane but I'd love to feel that kind of power. Your vid's give me goose bumps all over. According to http://www.bankspower.com their chart shows it's making 8psi boost at 3800 rpm and the curve is really really flat, Couple that with the fact that it is a 13:1 motor (might get lowered to 12.5) I'm thinking it'll still have pleanty of low end, so that's why I'm thinking 2500 stall. I emailed a converter build sheet to Torco/Art Carr" Mickey Anderson yesterday for recommendations which includes the weight of the car, details on engine, etc. I'm looking for a spragless converter that'll stay together and I simply love my 4K stall that I already have.

 

Just for info, Torco bought Art Carr, but now Art Carr bought it back, but still markets under Torco as well. Torco is a industrial converter rebuild and manufacture shop, I bought converters from them for heavy diesel applications, they are located in El Paso, TX and that is where they built my 4K stall that lifts the z's front wheels nicely. If you don't think or haven't thought that a converter can make all the difference in the world, then you ought to try one of their custom converters, guaranteed to 850HP for about $350 delivered.

 

Hanns, on the blow through carb, it is my understanding that all you have to do is change the floats to solid type, is that correct? What about jets, jet up or down or how did that all come into play?

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My 4K stall has only 5% slip on the top end. I know that 5 to 10 is the norm. Let's figure 10 anyway as a fudge factor with the 29.5 tall tire, a little turbo lag never hurt anyone, besides, it'll give my opponent a false sense of security when he beats me off the line.

 

Wheelie bars and chute, hmmm. chute I can definately agree with, comes into play at 135mph as per NHRA rules, the wheelie bars we'll have to see how it acts, I'll play with it at first with low boost. The banks system has adjustable waste gates from 5 to 20psi. Wheelies kill et and it's kind of hard to drive when you can't steer. Now if I don't line the z up straight it'll scare the pants off you when it launches.

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You got me all excited just thinking about your setup!

 

800+hp and 600+ lb/ft torque. Is that RWHP or flywheel? Torque figure sounds low. My buddie's 4.1L V6 (same as I just built) recently dyno'd at 540rwhp & 630 lb/ft with a badly slipping converter. We feel it can come close to 600. The V6 Buick is a lower revving torque monster but the V8 does have a lot more cubes.

 

Getting the converter right is absolutely the key and I am very familiar with the Art Carr folks in TX. I was running their 9.5" 3400 stall lockup unit in the Z cutting 1.30s and putting a little air under 1 front tire with IRS and only 520rwhp! Took me 2 restalls to get it right. BTW, never heard of a 4K stall non-lockup having only 5% slip but if it is that's great. Heed Hans' warning. With that much power, compression, 4K stall, solid rear and the Z's F-R weight distribution, THE FRONT WILL BE COMING OFF THE GROUND BIG TIME!

 

So let's continue playing what-if (I love racing other people's cars :D ). If I assume 850 at the flywheel, then you have 705rwhp with 17% drivetrain loss. With that I estimate the car will go 9.20 @ 149.75 (at least a 10-pt and parachute needed). Here is what the numbers look like now a with 29.5 tire:

 

2.73 - 5,250

3.07 - 5,900

4.11 - 7,900

 

The numbers say a 3.23 would put you at 6,210.

 

BTW, which alky-injection system are you planning on using?

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Scottie, I'd die for alcohol injection system, I'm planning on running the C&S aerosol billet carb for now as a blow through system and then possibly upgrading to the accel EFI later. Accel makes a 160Lb/hr injector and that would be necessary to support this kind of HP. I just don't have the money right now to do it all, still recovering from the witch of eastwick that absconded with alot of cash when she left. She was kind of like a tornado, alot of blowing, sucking and when I woke up the next day my wallet and trailer house was gone!

 

3.23's, well, I'll see what I can find on EBAY for 9 inch ford gears.

 

I got a quote from Alan Hartman this AM, $670 delivered for a custom converter and yes, they will restall it as necessary until I get it right, but I need to have some kind of idea where to start from as far as stall goes. He suggests a dyno pull, but I called Edwards and he's booked up on the dyno since he's semi retired now.

 

This'll be great, $4500 for a complete TT setup including cam and converter.

 

Measuring on the z this am before I had to go to work, sorry Hanns, the inner fenderwells gotta have some torch action to get it to fit as delivered. 36" outside turbo housing to outside turbo housing. Turbo's sit right in front of the struts. Of course, there's always custom exhaust housings that could be fabbed. We'll see when it gets here, I'd like it all to fit inside the engine compartment as is, as it would be cleaner. I'm so jazzed it's about all I can think of.

 

Banks hasn't done alcohol blow through and if you read their website, they advocate using gas only, but they pandor to the street crowd, not the racing crowd. This is really outside their envelope, but I'm usually outside the envelope anyway. So they are guessing at HP and torque values.

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Hanns, on the blow through carb, it is my understanding that all you have to do is change the floats to solid type, is that correct? What about jets, jet up or down or how did that all come into play?

 

* Nitrophyl Floats

* Bigger Needle & Seat inlets (Steel)

* Huge jets for alcohol

* Since the front end will come up everytime you launch, Power Valve in

secondaries is useless. And you need Jet Extensions on secondaries.

* For alcohol you need to drill out main passageway in metering blocks

(you probably already have that).

* Smaller High speed Air Bleeds

* Unobstructed vents for fuel bowls so that fuel can be pressurized at a 1:1

ratio.

* I don't know how much fuel pressure is seen by the regulator with alcohol

but the regulator also must be indexed for a 1:1 ratio rise with boost.

Otherwise the boost will blow the fuel back into the tank under boost.

* Really big alcohol pump. Must have high pressure and high volume.

 

Points will be deducted for cutting into inner fenderwells for turbo clearance.

But I forgive you!!!

Hanns

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Got all that in the carb already, they are saying that the fuel metering needs to be calibrated for blow through and to send the carb back.

 

The aeromotive A2000 pump will go to 32 psi, so 7.5 psi at the carb should be good to 20+psi boost. Regulator is on the way, boost referenced. I'll run calc's and see if I've got enough volume to handle the HP.

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Most definately, doing preliminary measurements and something has got to give somewhere. I'm trying to figure out how to tie in the front frame rails with the rest of the cage and make it a 12 point cage instead of the 10 point I have now. I'm sure at some point I'm at least going to have to have the cassis certified, although I don't think I want to mess with NHRA liscense right now at this point in my life.

 

But I will take some pic's, got to run to the bank tomorrow and get a cashiers check and pop it in express mail to the guy, it's ready to ship and I should have it all by Friday so I can do some mock up and take measurements and pics.

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The aeromotive A2000 pump will go to 32 psi, so 7.5 psi at the carb should be good to 20+psi boost.

 

Be careful, I'm selling my A2000 on E-bay, right now. Aeromotive Tech people said it can be adjusted to a max of 22 PSI. I actually made a longer adjustment screw and was able to get 25 PSI ( pump was loud ). Still not enough pressure for my 17 PSI boost. I tested the free flowing volume and it was like a garden hose. Maybe I didn't install it properly or had insufficient electrical current.But I used it just a few times and then replaced it with an FI pump (pressure problem solved).

7.5 psi + 20 psi boost + 3 psi friction in fuel lines + 2 psi fighting gravity and moving forward to carb = 32.5 psi total and no margin for error.

If you already have it try it, if not enough pressure get a Kenne Bell Boost-a Pump.

Good Luck,

Hanns

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DR Hunt, It sounds like you have a really wicked combo in the works. Please post pics as you go. IMO, it seems your Z is leaning more toward track use than street, just my opinion. I must say it sounds like it will be wickedly fast. I saw the pics of your Monte by the way, nice car. No wonder "they" tried to steal it 6 times. Although your project sounds awesome, I am a true Turbomeister fan. I will keep tabs on your progress as well. Maybe you will motivate Mr. T to add an intercooler and some slicks. Who knows, it will be interesting to have 2 bad-a$$ turbo V8 Z's on the forum. Good Luck!

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We'll try it and see, what happens on 12psi, might even order some lower pressure springs to start with and see how the chassis reacts and what kind of speed on the top end develops. Baby steps first. I got 28psi closed out of my A2000 and can't get it below 22psi, so we'll see how it works.

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jbk240z, no, my boy and I drove it 6 miles one way to a buddies house and back on the back roads so probably 15 miles total, just cruising and it used 10 gallons of alcohol, so it's definately not a long hauler. I cruise town with my boy on weekends, make a couple of drags down main and head home just so he can enjoy the car, he drives on the back roads too. That may change though, I can switch from gas to alcohol and will be able to do so with the right compression also with the turbo, Muhahahaha!

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I calculated it exactly and it has 12.68 compression now and the limit for alcohol is theoretically 12.5, so that's close enough, gives me a boost limit of 19 psi. The latent heat of vaporization for alcohol is alot greater than gas and the air intake temp is drastically lower for alcohol than for gas in a blow through environment and the octane equivalent of alcohol in relation to gas is 150. This allows for alot more static compression to be run under boost. Couple that with the overall increase in BTU's at correct AFR then you end up with about 200 more HP under identical boost conditions than you do with gas. So, in a nutshell if you can make 600HP forced induction with gas, alcohol will net about 800HP all things (hard parts) being equal. This system is set up for 16psi boost. On a 350 chevrolet with 100 octane gas, non intercooled, produces about 800 HP, so on alcohol with excellent AFR heads, roller cam, should make in excess of 1000HP at the flywheel and should net over 800 at the wheels. Pretty incredible considering it's only 16psi boost. I'd really like to order another set of AFR heads and leave the combustion chamber at 76cc which would drop the compression down to 9.5 and turn the boost up to 22 psi which should net around 1300HP and over 1000TQ, now that'd be a ride that would put a smile on ol' grandma.

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As Deep previously posted you must have balls of titanium. Your Z is going to be a handfull and then some. I think full track length burnouts will be possible. I really like the alcohol fuel idea, the only downside I see is it comsumes so much more fuel. 10 gallons to go to Walmart......j/k. I know you'll keep us posted on your progress. I wish you the best luck in getting the Z going. Oh, be sure to bring an extra set of underwear when you go for the first spin......LOL!

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