New 555 Hybrid F/D Option - 3.05

[TurboGLH]

We'll soon be offering a 3.05 F/D with our 555's.

Perfect for those of you making power at a level where 3.50's are now a limiting factor, or even for those of you who want a highway cruiser.

At this point the only diff option tested is an stock open diff, but a obx or quaife should be available pending testing.

[iTurbo]

Let me see if I got this right..

You guys can now build an A555/A525 hybrid, using the A555 gearset and case with the A525's 3.05:1 FD..

but you guys can also build an A525/A555 hybrid, using the A555 gearset in a A525 case with the 3.05:1 FD?

So essentially they would have exactly the same ratios except one is in the A555 case and the other in an A525 case? I actually have both of these core trans; I might actually put them to good use someday.

[cordes]

Chris, what would you say is a good HP to switch to the 3.05FD from 3.50FD in an L-body? I know that a lot of guys with the 3.50s in Ls with 350+HP seem to have some traction problems still. The idea of this setup for both traction, and wicked freeway driving excites me greatly.

[8valves]

Chris, what would you say is a good HP to switch to the 3.05FD from 3.50FD in an L-body? I know that a lot of guys with the 3.50s in Ls with 350+HP seem to have some traction problems still. The idea of this setup for both traction, and wicked freeway driving excites me greatly.

I dunno, I'd be curious though. As is my gearing is good for 156 mph in 4th gear at redline on a 3.50 FD 568. I'm not sure if going to longer gears would really be a benefit or a hurtful deal at this point.

AM

[cordes]

I dunno, I'd be curious though. As is my gearing is good for 156 mph in 4th gear at redline on a 3.50 FD 568. I'm not sure if going to longer gears would really be a benefit or a hurtful deal at this point.

AM

That is a pretty strong statment about the power needed to push that FD given the numbers you are laying down. Thanks for the reply.

[TurboGLH]

Let me see if I got this right..

You guys can now build an A555/A525 hybrid, using the A555 gearset and case with the A525's 3.05:1 FD..

but you guys can also build an A525/A555 hybrid, using the A555 gearset in a A525 case with the 3.05:1 FD?

So essentially they would have exactly the same ratios except one is in the A555 case and the other in an A525 case? I actually have both of these core trans; I might actually put them to good use someday.

Right. We've managed to fit a 525 ring gear into a 555 case. I've the test setup sitting on the garage floor right now with a 3.87 525 shaft and gear mounted correctly into a 520/555 case. Since the weak point in a 525 has always been the diff, this now allows that last hurdle to be overcome.


Chris, what would you say is a good HP to switch to the 3.05FD from 3.50FD in an L-body? I know that a lot of guys with the 3.50s in Ls with 350+HP seem to have some traction problems still. The idea of this setup for both traction, and wicked freeway driving excites me greatly.

At this point I have no honest answer. Just like the first few 3.50 555's this will be for the more brave to try out and give feedback. We've got a 525/555 with 3.05's on order from a customer right now, with the new option he may or may not be interested in going with a 3.05'd 555 instead. If so, then he'll be able to give us some good feedback on driveability.


I dunno, I'd be curious though. As is my gearing is good for 156 mph in 4th gear at redline on a 3.50 FD 568. I'm not sure if going to longer gears would really be a benefit or a hurtful deal at this point.

AM

It's an unknown to us as well, but the occasional person comes around asking about using a 3.05 and it seem that there was enough interest for warrant taking a look. What the hp/weight requirements turn out to be is up in the air.

I am curious what your redline/tire size is? For most people running a stock sized tire with a 6500 redline 4th is only good for 140mph. So I'm curious of your extra speed is from a larger diameter tire or higher redline or both maybe.

[Mario]

Shifting at 7200 and having a tire size of 23.87? :D

[8valves]

23.9 actually, and maybe 7500 this year, or more.

I'm not putting it (the 3.05) down at all, I just seriously wonder if it'll be an advantage at that point. I think maybe 2.5 guys might like it better letting the car sit on the torque table for longer, as opposed to a car like mine that is going to want to swing up higher more often. That was all I was saying.

Thanks to you and your father for working at releasing new options for people!

AM

[TurboGLH]

23.9 actually, and maybe 7500 this year, or more.

I'm not putting it (the 3.05) down at all, I just seriously wonder if it'll be an advantage at that point. I think maybe 2.5 guys might like it better letting the car sit on the torque table for longer, as opposed to a car like mine that is going to want to swing up higher more often. That was all I was saying.

Thanks to you and your father for working at releasing new options for people!

AM

I didn't take it that you were putting the idea down, you had a valid point and I just wanted to be honest and say that I didn't have an answer at this point.

The reason I asked about the rpm/tire size is that if your able to do 156mph in 4th because of a large tire, thats an option that other people can pursue without too large an investment.

But most people don't have the hardware to spin their motors to 7000-7500 rpm on an 8v. They also haven't done the work to reduce low rpm torque in exchange for higher end hp like you have.

So I was just trying to gauge if it was your relatively unique hardware or something a little easier to obtain for the masses.

[tryingbe]

I don't mind reving 2400rpm on 5th going 60mph compare to 3100rpm.

[Garret]

I totally like this idea, I'll let you know more around spring time when I am getting ready to do a clutch about getting this put in a transmission for myself

[GLHSKEN]

Definately interested... what do you need for cores.. shoot me a pm with the price.

I understand Aarons question.. but 7500 is way higher than I wanna go with the engine. Hell, I DEMOLISHED a 3.05 on 205's at a 4-5 (122mph) shift at 6k rpm with a STOCK car (broke the windshield of the guy I was running with trans pieces!!)

[contraption22]

I dunno, I'd be curious though. As is my gearing is good for 156 mph in 4th gear at redline on a 3.50 FD 568. I'm not sure if going to longer gears would really be a benefit or a hurtful deal at this point.

AM

It all depends on your available torque at low RPM, traction, and how fast you really wanna go top-end wise i guess.

My old Neon needed every bit of it's 3.94 FD to get out of it's own way, but on long highway cruises at 3500rpm, i longed for a 3.55 trans. Ideally, a 6th gear would have been great:)

[TurboGLH]

Definately interested... what do you need for cores.. shoot me a pm with the price.

I understand Aarons question.. but 7500 is way higher than I wanna go with the engine. Hell, I DEMOLISHED a 3.05 on 205's at a 4-5 (122mph) shift at 6k rpm with a STOCK car (broke the windshield of the guy I was running with trans pieces!!)

We'll be needing 3.05 cores, only have one right now. The price will be more than a regular hybrid, it requires some machining to be done in order to utilize the ring gear and that will add to the cost. As soon as we get a firm idea on the extra cost's involved the info will be posted.

[GLHS0658]

Personally I think this is a great idea. This is on my work bench right now.
IMO, I think the 3.05 is better suited for a 2.5's stroke.

I got this idea a few years ago when one of the car magazines tested a Chevelle with a 406. A 3.75" stroke engine went 12.6 in the 1/4 with 3.73 gears
but went 12.11 with 3.55 with no other changes.
and went 12.21 with a 3.08
I went on to read that
3.90 is good for a 327 3.25 stroke
3.73 for a 350 3.48 stroke
3.55 for a 383/400 3.75 stroke

so a 3.05 would be just about right for the 4" stroke of a 2.5

Mike

[Putter]

A 3.05 is going to be a stronger gear than the 3.50's for those of you concerned with the strength, as the gear is larger it has a better contact patch.

I have a 3.05 gearset on the shelf in my garage if you're interested. Let me know.

The biggest problem I see with it is if the car is too high powered for the 3.50's (which I know there are cars that are) putting in the 3.05 is only going to increase the load on the gearset/clutch. I don't know what the limits of a 555 are, but if you're already 350+hp and you transfer a little more load on the gearset I'm afraid of what the results could be... But thats racing, and carnage is sweet!

[PentastarTurbo]

I'm confused about how the FD ratio works..

I have a Ramsdell 555 w/3.50fd

Does that mean that the 1st - 4th gears are going to feel the same as if it were a stock 555 thrown into an L body? I really liked how 1st would really get the jump off the line..

With a 3.50fd. does that change how short 1st is going to feel?

To tell ya the truth, I've never had the opertunity to run this transmission and its still sitting in the crate it was shipped in..

So I dont know.. All I remember was how high the RPM's were taching up in my GLHS with a stock 555 and I hated that..

I'd love the stock 1st - 4th gearing as if it were a stock 555 in an L body but I just wanted a better freeway gear to keep the rpms a bit lower for freeway cruising..

can anyone set me straight on this?
thanks

[Mario]

If you wanted to simply modify fifth gears' ratio, you'd have to do just that, get a different fifth gear made. A different FD ratio modifys how tall or short all of the gears are.

[PentastarTurbo]

the stock internal 555/3.85fd ratio in my GLHS with a bad wastegate actuator (7psi max) netted me a 15.2 @ 90 something..

I've wondered what a 14psi grainger setup with a proper can would have netted me.

Hey Cliff..

Could ya put a low 5th gear from another transmission be installed into that 555/3.50fd setup I bought from ya?

I seem to remember my 5 speed bone stock Rampage having a really nice low RPM in 5th on the freeway..

I misunderstood that fd was the whole gear ratio..
Thought it had something to do with just 5th gear..

I suppose I asked the wrong answers and got the right answer before I went for this trans LOL

[TurboGLH]

the stock internal 555/3.85fd ratio in my GLHS with a bad wastegate actuator (7psi max) netted me a 15.2 @ 90 something..

I've wondered what a 14psi grainger setup with a proper can would have netted me.

Hey Cliff..

Could ya put a low 5th gear from another transmission be installed into that 555/3.50fd setup I bought from ya?

I seem to remember my 5 speed bone stock Rampage having a really nice low RPM in 5th on the freeway..

I misunderstood that fd was the whole gear ratio..
Thought it had something to do with just 5th gear..

I suppose I asked the wrong answers and got the right answer before I went for this trans LOL

5th is already as low as it can go (well, you could use a .71 5th from a 568, but it won't make any noticeable difference from the .72 you already have)

As your power level goes up you'll appreciate the 3.50 more, especially in a rampage.

[Frank]

It would be cool to see someone forge new intermediate shafts and ring gears to go with the 523 gear set. A 3.0 FD would be amazing. Then it could go with 523/543/568 sets.


Frank

[rbryant]

5th is already as low as it can go (well, you could use a .71 5th from a 568, but it won't make any noticeable difference from the .72 you already have)

As your power level goes up you'll appreciate the 3.50 more, especially in a rampage.

I thought you couldn't change just a single gear because then wouldn't match the input shaft....

Am I missing something?

-Rich

[TurboGLH]

It would be cool to see someone forge new intermediate shafts and ring gears to go with the 523 gear set. A 3.0 FD would be amazing. Then it could go with 523/543/568 sets.


Frank

I can't even begin to think what the cost on something like that would be.

Another idea that I've never tried, but might be possible is to use a early mainshaft and 1/2 gears with the 568 slider to allow the use of a 3.05 in a 568. I'll have to look into that if I get a chance.



I thought you couldn't change just a single gear because then wouldn't match the input shaft....

Am I missing something?

-Rich

5th isn't cast as part of the input shaft. So if you wanted to, you could use a 523 or 568 5th gear on a 89' 520/555. No real reason to do so, the .01 reduction in gear ratio would produce an immeasurable drop in speed.

[tryingbe]

I'm confused about how the FD ratio works..

I have a Ramsdell 555 w/3.50fd

Does that mean that the 1st - 4th gears are going to feel the same as if it were a stock 555 thrown into an L body? I really liked how 1st would really get the jump off the line..

With a 3.50fd. does that change how short 1st is going to feel?


For the same speed and same gear, your rev will drop by about 10% going from a 3.85FD to 3.50FD.