project89

iTrader: (1)

i expect somewere in the 11's not putting to much faith in the 255 bfg ta's though , its going to be hard to get the car to hook on those tires with the 4,500 stall converter but ima give it my best. mph will tell the story though

Street Lethal

iTrader: (16)

I have a feeling it will stall much lower than that, despite being rated at 4500-RPM. I have a 3500 in mine, and when I tested it a few days ago, once the vacuum/boost gauge hit 0 when power braking, it coupled at a little above 2000-RPM, although it will "flash" much higher than that though, no doubt.

anesthes

iTrader: (12)

Depends on what HP the stall was rated at. It's not an electronic device that releases a clutch at a specific RPM. It's a guess based on fin size and angle.

My converter stalls around 2800 on my 412. On a smaller engine it would stall closer to 2400 rpm.


I agree with shooting for top MPH. I don't know about you guys, but I can't go faster than 11.49 without spending another 7k in safety bs. I can run up to 139mph though. Light the tires on fire at the three and drive it like you stole it.


-- Joe

Street Lethal

iTrader: (16)

... what I meant was it is a lot like cam manufacturers. Most companies immediately assume that the buyer will ask for too much, so getting what it was advertised for is not really always the case. Final say is when he throws up videos to confirm stall speed if people really are curious though, and if that is what he ordered then hopefully that is what he got. I don't think it will stall that high though, even with more horsepower, but that's just my opinion.

anesthes

iTrader: (12)

Won't dispute that.

I think sizing a converter on a turbo car is tough anyway. It's not like a n/a car where you have a flat power curve.

-- Joe

Orr89RocZ

iTrader: (20)

Stall is gonna change with boost. So it may get to 4500.

Mine was suppose to be 4500-4800 ish as it seems to flash in there on hit off boost but if boost is high and it comes in fast, it opens up more like 5500-5800. I once forgot to take brake off the dyno and tried a pull it stayed at 5500 on just 15 psi boost

anesthes

iTrader: (12)

That thing must be fun driving to the local ice cream shop.

-- Joe

Orr89RocZ

iTrader: (20)

Off boost it feels like a 3000 stall, no looser than my old 3200 stall in my 99 trans am. Yes it is very fun to drive lol. Thats why good converters cost as much as they do lol

project89

iTrader: (1)

before i go im going to put it on the transbrake and see were it goes, im sure it will go 4,500 on the brake , footbraking it will prolly only goto around 3k before the brakes cant hold it

must resist using brake at track for giant smoke show though that poor 10 bolt will become a grenade im sure even on street tires

Street Lethal

iTrader: (16)

Let me just clarify. The transbrake will hold well beyond your stall point, as this is why some racers will leave the line already in boost. Your stall is determined by hooking up a boost/vacuum gauge, torquing the engine up while holding the brake, and once you see 0 on the gauge, that is your stall point. The converter will still "flash" way after that because flashing is sudden, but that is not your stall point, that's your flash point. The transbrake will hold well beyond your stall point, but that doesn't make it your true coupling point. This is why I said I doubt you will see 4500-RPM as your stall point, but should in fact see 4500-RPM as your flash point...

Orr89RocZ

iTrader: (20)

What?

Street Lethal

iTrader: (16)

What don't you understand? A converter's true stall speed is when you apply the brake, torque up the engine normally, and when the vacuum/boost gauge hits 0, look at your RPM, and there is your stall speed. Flashing the converter is not done that way, flashing the converter is simply mashing the gas suddenly and flashing it higher than its rated stall speed. Example; D6 converters stall at 1600-RPM, but flash in the low 2000's. D5 converters stall at 2400-RPM, but flash at high 2000's. What is so hard to understand?

Orr89RocZ

iTrader: (20)

Flash stall is as you say. You mash gas launch vehicle and observe rpm at which vehicle starts to move

But where do you get this idea that true stall has anything to do with vacuum??

True stall can only be tested by transbrake where drivetrain is locked and you bring rpm up until converter stalls and no longer rises any higher. That is true stall. Engine will not keep reving on transbrake.

Flash speed is always gonna be lower than true stall because forces in the converter will start moving vehicle well before rated true stall. Thats why a car will move forward in gear at idle with 4500 rated stall. Its still capable of transfering torque just not alot but sometimes enough to move the car

Street Lethal

iTrader: (16)

Stalling the converter and flashing the converter are two entirely different things, thus the reasoning behind the two terms. Flashing the converter will always yield a slightly higher RPM point depending on an engine's horsepower, but this does not make it the "true" stall speed. True stall speed is exactly that, when an engine couples with the transmission normally, and this is easily determined via watching the boost/vacuum gauge, or datalogging. I can control when the converter couples with the transmission by doing a neutral drop, but this does not mean that is the stall speed of the converter. Incidently, nobody said a transbrake will not help find a coupling and/or stall point, what was said was a transbrake will hold past that point, that is the purpose of a transbrake, to build boost while holding the engine back from moving, but that does not make it higher than what it really is. If that is the case, I will go out and rev my engine to 6000-RPM in neutral, slam it into gear, and now I suddenly have a 6000 stall speed converter...

Orr89RocZ

iTrader: (20)

I will trust major converter manufacturers definitions of true stall. Go try it. Get a converter and a brake. Push and hold brake button and see how many rpm the engine can achieve before it gets "stalled" lol key word there stall. Thats stall speed.

Finding 0 boost on a gauge is irrelevant.

Carry on

project89

iTrader: (1)

heres how i left the car yesterday , going to leave the turbop off it today finish putting the ecm back in and hopefully fire the engine

Street Lethal

iTrader: (16)

Look, everyone has their own opinion when it comes to converters and how to calculate true stall speed. Foot braking is the most common method if the brakes hold, flash stalling is the next of course but not very accurate in my opinion, and of course there is now transmission braking. A simple datalog used in conjunction with all three will tell everyone what they need to know and narrow it down in the end. Getting back to what I originally said before it was misconstrued, I don't think he will be able to stall at 4500-RPM. Why? Because we are talking about an engine, that in the very page before this one, is hoping to run an 11.50 pass. I just don't see the engine making enough power to bring the converter that high. But as I already said, test it and we shall see...

Car looks great Dave.

Orr89RocZ

iTrader: (20)

That car with cleaned up heads and half decent sized cam should have no problem getting 11.5 power on mild boost.
Totally depends what the converter was made for. Its quite possible it will get to 4500. If its a nitrous converter from a 9-10 sec car then no it may not get to 4500.

project89

iTrader: (1)

its custom built for my combo builder has all of my combo specs , that being said it was speced with the intentions of running around 20 psi , so i dont know what its going to do at low boost we shall find out soon enough though

car really needs a solid roller cam to make the best power just wasnt in the budget right now , but i expect the xe274 to do fairly well

34blazer

It is my understanding that converter stall(for boosted apps) happens at 0-1 psi, and flash is when the converter couples at max power.


Also, I didn't see anyone mention anything about the stator when configuring the converter for a certain stall rpm, as it also plays a role.

Orr89RocZ

iTrader: (20)

You will never get flash to couple at max rpm rating because there is not enough load on the converter. Do a launch in 1st gear and see one flash point. Do a launch in 3rd and see another flashpoint. But car will move at some point near 100% couple but never at that value. Only way to see where it "couples" is when drivetrain is locked so only the hydraulic part is spinning and seeing engine torque load.
Can you share links discussing stall as it relates to engine vacuum or 0-1 psi as you mention? I have never heard this and dont see how thats relevant at all. Its a hydraulic device. application of trq input to the fluid trying to hold it back from slipping is the only thing that matters

If it was designed around torque at 20 psi which would be upwards of 700-800 wtq then at lower loads its likely gonna be a few hundred less rpm

project89

iTrader: (1)

yeah im pretty sure the 4,200-4,500 number is going to be the stall at full engine tq, prolly going to be around 3k-3,300 on mild boost and foot brake if the brakes hold.

if they got the converter right i should be able to build close to max boost ont he brake , the trick will then be getting the car to hookup leaving with that much power

Orr89RocZ

iTrader: (20)

You wont hook most likely on max. Nobody ever leaves on max. You will have to find that limit to what it can take, and then work on ramp rate on how the power comes in. Boost control and timing are your friends there

Only thing that matters with converter stall on boosted car is that you can get some boost at the line somewhat quickly on the brake before overheating the fluid, and that it doesnt blow thru slipping past your peak hp rpm. If it stalls anywhere inbetween peak trq and peak hp, its gonna work fairly well lol

For me in the 1000 whp range, i try to leave on 5-7 psi and if track holds i let it come in as fast as turbos can produce it. Got me 1.31 60 in this 3800 lb rig. If track doesnt hold well i gotta ramp, leave 4-5 psi and do something like a 6-9 psi per sec ramp. That will get mid high 1.3's sometimes low 1.40

junkcltr

iTrader: (1)

Car is looking great.

Wow, that is some interesting opinions of true definitions in regards to stall speed.

Can someone answer this? I have a manufacturer rated stall of 1800-2000 rpm. The vehicle will foot brake to 2600rpm making 2 PSI at 30% throttle. At 0 PSI, it is around 2300 RPM. What is the stall speed?

Orr89RocZ

iTrader: (20)

Thats why buying a shelf rated converter really can vary. Gm replacement for a stock 305 lets say its stall rated 1600. Slightly build motor and more torque it footbrake stall goes to 2000 with good brakes, then the true stall on that particular converter is gonna be somewhere around 2000-2500.

True stall shall vary on power. Thats what i see in my logs when i go from 700 whp levels to 1100 whp levels. Its a good 500-600 rpm difference

junkcltr

iTrader: (1)

I agree, a function of torque.

What is the rear end gear ratio? I think it should still mph for 10s if tuned decent.

sailtexas186548

iTrader: (2)

Since stall speed is dependent on input tq/power, and as boost builds so does tq/power, picking an arbitrary boost pressure to determine "stall speed" is just that, arbitrary. What is relevant is that the RPM the converter stalls at, while the engine is making the desired launch power (or launch boost if you prefer that metric), is an RPM that is desirable based on the engine's power band. You want to leave with 850hp and 4800 RPM - you need a converter that stalls at 4800rpm with 850hp @4800RPM input from the engine, any engine.

Boost is just a different metric - you have a hydraulic coupling with an input and output, locking the output (transbrake) and applying a certain input power (whatever your want it to be) determines the "true" stall speed of the converter @ that input power level.

Flash stall deals with dynamic/momentary loads on the converter, and is a very complicated load case and can show a variety of "stall speeds". I'm not going to go into it LOL, unless everyone has a solid grip on FBDs, dynamics, fluids, and some general impeller design knowledge

sailtexas186548

iTrader: (2)

DING DING DING WINNER

project has 350 cubes, if he can tune it to 1hp/cube before boost (easy enough) and throws 10psi at it should be in the neighborhood of 550 crank HP, I would think he can get into the low to mid 120MPH range

project89

iTrader: (1)

if i wa son slicks and it only went 120mph id sell the car , lol fasteddi is going 120's with 191ci and 14 psi , my v6 car goes 115@9 ish psi

but seeing as ill be on some so/so street tires i do see 120's being about as fast as it may go

Street Lethal

iTrader: (16)

Never mind Fasteddi, this is Bob, fellow member of the Turbo Buick community. Hot air LC2, teeny tiny 206/206 cam running a much smaller 6262 turbo w/.85 hotside. Put down 424/536 at 24-psi with very conservative timing controlled by the EBL, horsepower peaked at 5000-RPM, pull was as high as 5500-RPM; 11.68 @ 116 in the 1/4 and getting faster

You should annihilate his numbers at the boost your planning Dave...

project89

iTrader: (1)

i didnt get anymore work done today when i was hopping out of the loader yesterday i hurt the shoulder i broke my collar bone and seperated it from my shoulder in the bike crash , hopefully it wont slow me down over the next few days

Orr89RocZ

iTrader: (20)

Well i will find out something tomorow for you. I'm running my 305. On street tire most likely but we shall see. Got meth kit parts installed just need to wire

If a v6 goes 120 on 14 psi that v6 must be modded and car is lightweight

I honestly expect 115 on 14 psi with my stock 305 lb9. Math points to 450 hp max at 14-15 psi and 36 lb injectors

My mild first gen 401 build went 135 on 10 psi. 3700 lbs. i'd expect your 350 to go mid higher 120's in 10 psi

project89

iTrader: (1)

both v6 cars are normal wieght if not heavier then stock due to the turbo stuff
for the most part they are stock engines with ported heads and a cam

the v6 stuff responds very well to boost

34blazer

The Gen 3 60v6 heads flow very well compared to the irons of the Gen 1, and 8445 heads. Bob's Buick has champion irons and the champion Hot-air intake. Full weight too. Used to live down the street from him and have seen it, driven in it, watched it roll down the track. That thing was impressive even when it had the TA33. I love that car since its an underdog and most people look at a HA car as a slowpoke.

Orr89RocZ

iTrader: (20)

Hot air running 24 psi???! Does he like 300 deg intake temps?!

34blazer

E85 and spraying M1 pre/post turbo. He turned it up to 26psi on the second pass. Intake temps were around 190.

Orr89RocZ

iTrader: (20)

I was gonna say i bet its meth. Imo its not hot air at that point

project89

iTrader: (1)

orr since u have the badass v8 and now the 305 turbo u need to pick up a 3.1 v6 car and well show u how to make it run 11s for around 1,500 bucks , i do belive one of the v6 guys has even broken 9's

Orr89RocZ

iTrader: (20)

Lol i will go 11's on this car and i am in about 1600-1700 bucks haha


Other idea was to freshen up the 401 and drop in a stock rebuild 305 to my black car already setup for drag. Really find out what a sbe 305 can do. But i dont think it needs redone for atleast another season

34blazer

I would love to see Orr drop an LZ1 in one of those cars.

Street Lethal

iTrader: (16)

Will she be up and running later today as scheduled, or no...?

project89

iTrader: (1)

heading over in about 10 mins , should be running tonight or tommorow morning

project89

iTrader: (1)

home for lunch got a lot done

radiator is mounted , made the upper radiator hose , got the wiring almost 100% done
need to pick up a few odds and ends and should be getting this thing fired up

Street Lethal

iTrader: (16)

That third pic threw me off for a second, thought you were working on a new set of handle bars for your dirt bike lol.

That is one funky looking radiator hose...

project89

iTrader: (1)

its upside down int he pic , it comes off the thermostat housing and drops the hose down and below the crossover and then out to the radiator , im going to have to put a 1/2 inch pipe bung in the top of it so i can fill the hose at the highest point

EDIT

forgot to mention when i came home for lunch my valve body gaskets were sitting on my doorstep didnt expect them to arrive till monday or tuesday , so maybe ill even be able to put some street miles on it before i go racing

project89

iTrader: (1)

heres that upper hose rob


cars prolly not going to start tonight i forgot my money when i went back so i couldnt pick up the stuff i needed to hook up the fuel system , just ran home now so i could grab my money and stop by at napa

im going to use the rest of the night to dbl check all the wiring and other stuff and then fire the car tommorow

now that the car is just about ready to fire up i can slow down and take my time and make sure everything is good

Street Lethal

iTrader: (16)

Came out really sweet Dave, looks great!

Cringing a little about the fuel lines up front like that, will you eventually go braided?

project89

iTrader: (1)

ive got hardlines to the front of the motor then lil sections of really good hose to go from the hardlines to the fuel rails to allow for engine movement. that long rubber hose u see in the picture was just there for me to figure some things out

eventually it will be -8 feed and -6 return from engine to tank

all i got done so far this am was install a couple hose clamps in between hauling hay , the good news is no more hay to haul this year so this afternoon i can focus ont he car unfortunatly after lunch is also the hottestttime of the day

jimw67

Are you running the stock ignition coil without an MSD? And how are you supporting the turbo weight?

Get it done - watching anxiously - best of luck.

project89

iTrader: (1)

stock coil no msd box yet , i may go coil on plug this winter so i didnt want to spend the money on the msd stuff just yet , that being said the stock coil + the megasquirt doing direct coil control will fire pretty dang reliably under a good amount of boost with the plugs at .025-.030

i havent made the suppotrt brackets yet but there will be a bracket bolted to the waterpump to support the wieght of the turbo

hoping to have some videos up tonight of it running without the turbo