Ok, here is the scoop. Me and my dad have a '78 Malibu that is a drag only car and this is the first year out with the car. The car is as follows...

Enigne: 357 SBC, with 12.5:1 comp, Dart Pro1 230cc heads that are unported, Dart intake ported to match Fel Pro 1206 gasket, T&D shaft rockers, custom Schneider solid flat tappet cam with lift in the .600 range and duration @ .050 in the 275 degree range on a 106( I will not be specific when it comes to the cam ) BG Drag Demon 1000cfm, MSD 7AL2 ingition with a blaster3 coil, and 1 5/8 headers that will be upgraded next year. Engine is in the 630 HP range at the flywheel and 500 on tourque.

Tranny: Aluminum PG with 1.76 first gear, full manual VB and a 3500-4000 stall.

Rear: Ford 9" with 4.11 gears, 28 x 9 MT drag slicks and stock suspension for this year.

The car is all steel with the exception of a 2" fiberglass hood. Car is stripped down for racing and weight is in the 2800# range with driver and fuel.

Now........ drove the car tonight on the street (oops...) and the car did not need to be shifted for about 1200 feet. I guess what I am saying is the car is a one gear wonder for the quarter mile. We are shifting at 7800 and I even short shifted at 7300, the car pulled like crazy and even barked the slicks for about 6 feet, but is a dog out of the hole. The converter is stalling at about 2500 and the engine does not RPM like it should (pretty obvious) so I was wondering about a rear gear recomendation. Thanks guys.

What RPM does the car go through the lights at on a quarter-mile track? Also, do you use a trans. brake to launch or a foot brake (a trans. brake will give you a better indication of how much stall speed your converter can produce with the engine that you have)? Assuming that you're not going to use nitrous (which this combination is BEGGING for right now) with your current set-up and that the engine is tuned properly AND that this is a drag only car (meaning that street manners aren't important), I'd suggest starting with AT LEAST a 4.88. You really need to get a few time slips first and then make your changes based on documented track performance. From what you have revealed, it looks like the converter is too tight and you definitely need more gear (a 4.88 is being conservative - probably will end up in the 5's somewhere if you're buzzing that mouse up to 7,800).

T-man

Well that is what I was thinking, baybe a 5.14 - 5.30 range. We are not running a brake this year, but WILL next year, we will leave the line from idle for this year. Don't know the rpm through the lights yet, just road tested tonight, but this is not a street legal car, drag only. As far as N2O goes..........NOT IN MY LIFETIME. DO IT ON THE MOTOR OR GO HOME. Sorry if I offend, but I am not a fan of N2O, I like pure HP from an engine.

No offense taken - nitrous isn't for everyone. I just wanted to make sure that you didn't have that intention in the future based on how the car is configured ( tight converter and a tall rear gear). Make sure you post your time slip averages and incrementals and then we'll be able to get that gear figured out. If you had a low "fiver" gear set to stuff in there right now, I'd try it ( the rev. limiter will keep things in check in case you over speed the motor before the finish line).

T-man

You only have a 7.2 overall 1st gear with the 2 speed/4.11 rear

...IMHO,you would be better off with a TH350,which would have a 10.19 overall 1st gear with 4.11's and the car would really come out of the hole nice

Whats the car currently run?

Yeah, a three speed would probably be a better fit but if you have to work with what you have, gear it. I love drag racing - there are SOOOOO many ways to send a car down the track ( last time I checked there were 2.8 million different combinations to power a car down the quarter mile................)
T-man

sounds to me like you aren't making anywhere near the amount if Torque you need to flash the converter you say is in there Maybe they sold you the wrong one....or the converter is not set up properly and is way too tight,

You need around 4500 to 5000 flash I would think (only guessing what the cam might be). Did you mean 275 @ 0.050 instead of the 175@.050 you listed?

Valve train adjusted properly? correct valve springs?

Is this a bracket car or a "Heads up" racer?

Thanks guys. The reason for the PG is the car was set up for it when we got it and I had a spare PG on the floor. The converter is a TH converter and we had the input shaft changed, I had the converter from another car I ran and when I removed the converter it did still flash at about 4000 in that other car. The other car was a SB 78 Monte with a TH400 and 4.11 gears, but it was a heaver car and less powerful engine. So I thought it was easier to run what I have on hand and not have to convert the over for a TH.


I have always heard that if a car is under 3000# it will run quicker with a PG than it will with the TH. Is that not true?


Good catch on the duration numbers, you are correct and I changed it.


As far as what class, NO class, just for fun. We are running for the sake of having a good time. I will post times as soon as we get some. Might be another couple of weeks though.


Thanks again, keep the ideas comming, I am open to any and all help.

Here is link to the engine beeing burped. Enjoy. http://www.putfile.com/media.php?n=357-Rev

BTW this site offers FREE video hosting!!!!!!

Why not specific on the cam grind? is it a secret grind? or you're just not sure? :confused:

The cam is something that I designed and had Schneider grind for me. I do know the specific numbers, but just don't want to give them out.

Sounds like you might have over done it with duration, if you can go 1200ft without shifting a gear.

In all seriousness it really sounds like you have a mismatched combination.

Changing the gears will not help to the degree you would expect it to.

I am a little confused on the secretive cam design, I could see if it was an NHRA or IHRA Class Car (Pro-stock, super stock or stock eliminator). If we knew the cam specs maybe one of the experienced small block engine guys could provide some more insight.

here is an example...my cam is 256 degrees duration at .050 and I have 540". My peak Torque is at 4500. My converter flashes between 4400 and 4600 depending on the weather and how good the track is. with your 275 degrees in duration and 180 less cubic inches and a 106 LSA says to me that your peak Torque could be in the 5500 to 6000+ range and very peaky so you need to hit it pretty precisely.

The car will remain a slug off the line unless you 1) change to a much looser converter (6000 ???) or change out your camshaft for something that works in your RPM range.

Now since I do not have all the facts and I never raced a small block this is just presented as a starting point and provides you with some guidelines. Although it is probably not what you wanted to hear, seriously look at the big picture and don't just throw parts at like rear gears (Yet).

The best way would be to go to the track and get some time intervals especially the 60 ft. Then modify the car for the best 60 ft's you can get while maintaining a relatively consistent mph.

Hope this helps...

I definitly think lower gears and possibly a looser converter would help. Those are some huge heads for a 350 so that's where the bottom end has gone to. I would run at least 4.88 gears and around a 5000 stall with your glide. Glides usually require a looser converter than a TH350 in my experience. By the way, your engine sounds pretty bad a**. Good job!

you need much more converter(5500 plus) and 4.56 gear to put you in the ball park to make that combo work with a glide..........remember a glide is a dull ride!.........but ...........with enough converter,tire and gear it might.........might........be fun. btw, how do you know your making 600 plus with that motor combo(seems a little conservative to me,but what the hell do I know)

.....possibly a looser converter would help.

Not possibly.................Necessary !

"would help" the converter is what the primary problem is.

DO NOT put the gears in until you know where you are in the RPM Range, then you can make an INFORMED decision.....Looser converters are also Looser on the Big End.

Assumming your cam is the correct application, the Converter is the first step in nailing down your combination.

I have done this a few times....

Thanks again for all the input, very good ideas to work with. I do think that a 5000-5500 stall is in order for this combo, then a gear change. I too am leaning toward the very high 4 to 5.20 range.

In response to the cam beeing wrong, I don't feel that it is the wrong cam for this engine. I designed the cam and then looked for the other engine parts that will work with the cam. I know the heads, compression, and all the other stuff that goes into picking the parts for a combo are up to the task. I do feel that the converter and gears are way wrong for the combo though. I ran high 11's with the Monte that the converter came out of and know what that kind of run feels like and this car, with only one usable gear, was pulling like it was running close to what my old car ran. When I test drove this car I came to a dead stop and nailed the car, ran it up to 7300 and shifted to 2nd gear ( which was about 1200 feet ) and when the car shifted, it turned the 9" MT slicks (with 7 1/2 pounds of pressure ) over for about 6 feet. I just think there is some tuning to be done to the drivetrain. Once that is all in order we should have a very fun ride.

I don't know the actual HP at the crank. those numbers I stated are from my Performance Trends Engine Analyzer program. We are going to take the car to the chassis dyno soon though and get the rear wheel power numbers, because that is what really matters. I will post them here after we make that trip too.

Ok, now let throw another thing in. We are going to be going to alcohol injection within 2 years with this combo.

Thanks to all for the input. I won't argue with anyone's adeas, and thanks for the nice comment about how it sounds too.

Good Luck and let's hear some results when you get to the track.......

4.86 gears in the "ice cream getter" Hope its not far to the ice cream stand, it will take you and Ed a while to get there :D Ed doesnt usually recommend gears that low,it doesnt follow the "BSE" way of thinking,all that torque ya know, now we know how the "red car" pulls those 1.5 foot wheelies :thumbsup:

I'm aiming at a 4.86 gear as my recommendation.....for his car.

5.20 is a bit much with a 28" tall tire and your combo,(comma ,end of thought, then you go on to say) i'm aiming at a 4.86 gear and an ATI 8" Treemaster.

You didnt say that in your first post Brian, now did you :rolleyes:

Pssst Brian, I'm using a transmission guy recommended by Ed, but you should know that, you know everything else.

I knew you couldnt stay away Brian,,,ask Ed who he recommended,and thought was a credible guy...of course I blocked you on AIM,,,I was tired of your profanity laced instant messages. Grow up Brian, all this hate will kill ya :D

Back to the post :D

I'm a bracket racer,shade tree welder,parts changer, engine assembler Brian,not a machinist,not a rearend builder,not a transmission rebuilder,got a couple of Ron Sessions books though... never claimed to know-it-all as you and Ed do. I've got 20k in my car, shoot Brian, another 20K and I'd be running as good as Ed does, he claims 40k in his car :D

Don't want or need information from you or Ed any longer,don't recall any useful information from you anyway Brian, its always send your heads here,send your transmission there, buy your parts here,hmmmmm kinda sounds like you know people and you are no more of a trouble shooter than I am, Brian. Ed recommended ATI, although it is a good converter, NO IMPROVEMENT in 60ft times vs. 11" B&M converter, he recommended 1.75" tube headers, which served their purpose,now I and others think are too small now, he recommended the 950HP carburetor, its a great carburetor. Ed spent his 40K getting his combo to work, let me spend my last 20K how I want to and see if I can't get a 10.2x timeslip, I can guarantee it will happen for far less. Oh yeah, last week our track became sanctioned by the IHRA, I might become famous now, like Eddie :D

Am I missing something here??? Is there some kind of quarel going on between you guys?

Took the car down to the scales today and here is what we got, front is 1660, rear is 1340, and total is 3000. All these weights are with driver and fuel. I know that we need to get it closer to the 50/50 split for front to rear weight and we will. We are adding fiberglass front and doors this winter along with lexan windows, so that should get us close.

Much looser convertor. Atleast 5500 maybe more. 2800# car will be faster with a glide if you get enough convertor in it. Go with 4.88s have have fun.

Thanks Mike, you must see the direction we are heading with the car. We are trying to do this without breaking the bank on the first year out, but I'm sure everyone has been there too. We can do it all right now , but there is another car we have in the body shop right now and have a very large bill comming on that one. The Malibu is a toy and will not be a priority as long as we are working on the other car too.

Sorry EM, didnt mean to hijack the post. Its a long story.

Ok guys, followed everyone's advise and ordered a set of 5.13 gears tonight. I decided to go about 1/2 way between what everone was saying for a gear ratio. We will probably just run the gears with the existing converter for this year though. I guess just changing the gears is a whole lot better than nothing. With the gear change it will put us at 9.0464:1 for our overall first gear ratio compared to the TH400 that would be 10.11:1 with the 4.11 gears we had. Hey, maybe it will loosen up that 4000 stall a little too. Thanks again for all the input.

How many rpms at the stripe? I guess it depends on converter slippage. Good Luck!!

Don't know RPM at the stripe yet. This is a new car for us, so I guess we will find out. Will let erveryone know as soon as we make it over to the strip.

Ok guys, followed everyone's advise and ordered a set of 5.13 gears tonight. I decided to go about 1/2 way between what everone was saying for a gear ratio. We will probably just run the gears with the existing converter for this year though. I guess just changing the gears is a whole lot better than nothing. With the gear change it will put us at 9.0464:1 for our overall first gear ratio compared to the TH400 that would be 10.11:1 with the 4.11 gears we had. Hey, maybe it will loosen up that 4000 stall a little too. Thanks again for all the input.

Not Really :(

Not Really :(



What? It won't lossen it up at all?

Just want to let you guys know we are going to the tack on Friday. We are not going to run hard though, still have the 4.11 gears in the car. Will post some times on Saturday or Sunday though.

Are you going to run at Cordova? Maybe I'll see you up there.

Yeah.... look for a black and silver 1978 malibu........ say hi if ya see me.....need some help.
This is the car....

http://img222.imageshack.us/img222/9968/100199127cs.jpg

Yeah.... look for a black and silver 1978 malibu........ say hi if ya see me.....need some help.
This is the car....

http://img222.imageshack.us/img222/9968/100199127cs.jpg

Nice looking Car

I do math for a living ( kinda), and I have it roughed up in the 5.88/6.13 range. :eek: Even a 2.50 1st gear and I think it would prefer 4.30+ rear gear, likely 4.56s. Launching with only a 9:1 gear ratio requires 5.13s w/Glide. Seems too conservative.

5.57s.


:D