t5 question

So, the T5 that I bought was misrepresented as to model. It actually came out of a 2.8 F Body car and the first gear ratio is going to be a bit low for what I want if I use the 3.3 C rear axle.

I have researched the different T5s that came in Camaro V8 cars and they seem to be pretty scarce.

My question is...Can the Mustang T5 be mated to my Chevy bell housing and will it do the job? As I sit here I haven't checked all of Mustang T5 ratio sets, but at least the Mustang version is a whole lot more plentiful.

BTW: My 2.8 T5 with tag number 1352-197 is for sale.

Jack

Yup, but I think the shifter is a bit further forward, which isn't a good thing. Check it out.

Jack,

According to: http://www.britishv8.org/Articles/Borg-Warner-T5-ID-Tags.htm Your current T5 has the following ratios:

1st: 4.03
2nd: 2.37
3rd: 1.49
4th: 1.00
5th: 0.76

Your going to install a 3.3 to 1 behind it leaving the ratios as following:


1st: 13.30
2nd: 7.82
3rd: 4.92
4th: 3.3
5th: 2.51


Now compare that to what I believe to be excellent ratios for a V6 T5 and a rear end combo:


1352-245 GM 1994 Camaro/Firebird V6 WC code:Z

1st: 3.75
2nd: 2.19
3rd: 1.41
4th: 1.0
5th: 0.72

Now place the rear end I like behind mine: 3.42 to 1. Yeah you can do a 3.23 GM axle as well, but I like a good hard take off once in a while while still giving great freeway capability in 4th AND 5th.


1st: 12.83
2nd: 7.49
3rd: 4.82
4th: 3.42
5th: 2.46



Your 1st: 13.30
My 1st: 12.83

Your 4th: 3.3 to 1
My 4th: 3.42 to 1

Your 5th: 2.51
My 5th: 2.46

Before I answer anything else, What's the problem???????? These ratios are ideal for both great take off speed as well as highway cruising. It is not ideal to have these ratios:

1st: 1 to 1
2nd: 1 to 1
3rd: 1 to 1
4th: 1 to 1
5th: 0.5 TO 1

Any more than it is to accelerate with a 2.95 1st gear with a 3.3 or worse a 3.07 to 1 ratio. This is a motor with great power and a wide powerband. With the correct rear end (3.3 to 1) a 2.95 1st becomes a 9.74 1st gear. That is almost second gear. This does not allow you to use the full powerband of your engine because your thinking in small displacement on a heavy car- that would require close ratio gears and more of them... Like a high revving motorcycle with 6 gears- keep it revved up. This is the opposite of that.

Hopefully I don't sound horrid here, just giving a lesson on what I have found best for the systems we have manufactured.

-BMC.

Jack, Bill Guzman, I believe sells the Ford to Chevy bell adapter for pre94 Ford T5. Newer Chevy V6 bells and some Jeep Cherokees have the Ford pattern on the bell so you wouldn't need an adapter. And just to make it more confusing the 94 and up Ford V8 and the V6 Mustang have longer input shafts and would need an additional spacer(7/8"-1") between bell and tranny. Which D&D sell. Mustang first gear ratios V8 and V6 are 3.35 first and .68 fifth (OD). Which I think would be perfect for your 3.31 MGC rear. I have a comparison chart on the British V8 site comparing Camaro V8 2.95 first with 3.90 rear, and Mustang 3.35 first with 3.31 rear, and Chevy V6 T5 with 3.07 rear. Very,very close, all good combos.

Another alternative trans would be the Colorado/Canyon MA5. About same ratios as V6 T5. You would need the Novak Chevy to AX15 adapter and AX15 front bearing retainer or Dodge Dakota bell for AX15. It has Chevy splines front and back. Same as Solstice but shifter is too far back on Solstice,might be a little too far forward on it(dogleg shifter).Made by Aisen Warner very similar to Toyota Supra trans.Here is a picture of one with V6 bell and Novak adapter.Supposedly smoother shifting and stronger than the T5. Bill S. would know having the T5 in the Jamaican and MA5 in the Solstice.

Dog leg Shifter picture. This ones for a T5. This is what Duncan needs for his MGA.

So Brian, what you are saying is to keep the 2.5 transmission with its 4.03 first gear? Am I correct?

I was under the impression that such a low first gear would be something of waste and would be too "short", but now that I think about it, I believe that you did in the past say that this 1352-197 box in front of the 3.3 C axle would be a good fit but maybe I am hallucinating. ... ;)

If you say that it is going to be a "good thing" that will make my day !

Jack

The funny thing is that the 4.03 sounds too low when you think about that number by itself But it's not when you consider that when combined with the right driveline Package, it's close but it should work.

Another comparison:
"Standard" 2.95 to 1 1st gear on a number of GM/Ford T5 units X MGB 3.909 rear axle ratio = 11.53 package 1st gear.
My Favourite 3.76 to 1 1st gear on a Camaro V6 T5 unit X 3.42 GM Conversion rear axle ratio = 12.86 package 1st gear.
Your Current 4.03 to 1 1st gear on a Camaro V6 T5 unit X 3.31 MGC Conversion rear axle ratio = 13.34 package 1st gear.


POOR First gear ratios:
The 3.76 V6 T5 with the standard 3.909 rear end = 14.70 1st gear.
The 4.03 V6 T5 with the standard 3.909 rear end = 15.75 1st gear.

The 3.76 1st gear 'box is barely tolerable with the standard rear end but it's almost something useful.

_____________________________


Now just as a separate comparison and to not make this post too lengthy or (yes I can make things confusing) err, confusing... Some added ideas on rear end ratios all-over-again.

Just first, not going beyond that for now:

4.03 with a 3.07 rear end = 12.37 first gear package.
I'll let you run the rest of the numbers on 4th and 5th but they will be high (speed) and low tick-over/RPM. As long as this is not combined with massively tall tires, it can still work this way as well.


_______________________________

Finally, after re-reading my numbers, I can tell you that my personal ideal 1st gear would be sitting at about a 12.0 to 1 overall ratio. 14.0 to 14.5 is to far in the hole and 9.5 to 10.0 is too far in the other direction. I did the math on what I have found and without manipulating it, 2.0 +/- is too much for me above and below.

MOST of these numbers will vary with your engine output. Where and how the power comes in to play and how much total power you achieve in full hard out runs. Your driving may not be the way to correctly determine this (not trying to start a fight) but how the car best runs out and then adjust your driving to meet the properly match driveline of the car. A carb'ed 3.4L V6 or 3.5L V8 may produce different results. I know there are a number of 215 V8 guys that would swear the 2.95 1st with a 3.07 is the Holy Grail.


So Brian, what you are saying is to keep the 2.5 transmission with its 4.03 first gear? Am I correct?

It is a 2.8L V6 T5 that is World Class according to British-V8.
I am not directly saying keep or throw but I think it will work fine. I'm pretty good at giving numbers but will let you consider either way. I would personally use it. :-)
If you were telling me that your rear axle would not have MGC gears installed and it would stay a 3.909 to 1 then I would say drop that thing like a bad habit. If you were going for a GM or Ford rear axle, I would say skip the 3.55 or 3.42 and go towards the 3.23 to 1 rear end ratio.

-BMC.

Brian...In looking at the graph on your blog site it looks like the torque curve for these engines is very flat. I was expecting to see a more pronounced "hump".

The graph is rather small on my screen, but I take it that if one were to try to correlate the issue of gearing with the presented graph line(s) it wouldn't matter much, as with such a flat line, looking for a gear set that would give better usefulness for one first gear over another would be pointless.

Open for comments about the above.

Although with your chart it might not be necessary, do you know of another source for Torque/HP graphing for the 3.4?

Jack

Jack,

I don't know if you are familiar with this site [url=http://60degreev6.com/forum/forumdisplay.php/62-Site-Articles][color=#CC0033]GM 60 Degree V6[/color][/url], but they have a lot of good engine performance information also.

In a general sense, with an engine producing a flat torque curve. it's OK to spread out 1-5 ratios and have top gear running at road speed with the engine running in the fattest part of the torque curve. This gives good gradeability with good economy and response. The going throught the gears will tend to take care of it self.

Unless of course we're talking about a race car!:)-D

Jack, I'm running a 2.8 with the same trans you have and using a 3.07 C rear and am very happy with it. I'm not trying to race people away from stoplighs, but wanted something with longer legs on the highway and this seems fine. This is just about the 12/1 in first gear that Brian likes, although with a 2.8 and not the 3.4. I just happened on a good deal on the engine and trans.
John

Brian, I agree with you most of the time, but I think Jack would be happier with the Mustang ratio trans because he wants to keep the 3.31 rear. If he wanted to go to the 3.07 it would be fine. At a typical 3000RPM shft point you would shift out of first at 16MPH with Jack's trans with the 3.31 rear and about 20MPH with the Mustang trans.Plus the lower numerical OD(.68 vs. .76)would help mileage and cruise RPM. The only 2.95 Mustang first gear are 83-84 NWC. There are new ones available from Ford Racing and the aftermarket.The dog leg shifter I intended for the MA5. I just mentioned Duncan because I remembered his previous post. Also as Jack found the popular T5's are getting scarce and I just mentioned some viable alternatives like the MA5 and longer input Mustang T5 because they are more common. Because they are less popular they are cheaper also. Here is a comparitive calculator I found,you can substitute lower RPM's for shift point calculations.www.fatboyraceworks.com

I HAVE to put this behind me as I am sitting here at about 3:30 in the AM still fixated on the problem.;)

Although I believe that I will end up with things being a little "short" I think that I will stick to what I have, unless a more suitable transmission floats by at an affordable price. The good news is that I live in the mountains and the shorter gears might be a little more palatable given the hilly terrain here rather than what I might find in Kansas.

At this point the only "bling" that I think that I will spring for is trying to modify the front of the 3.4 with a straight cut timing gear set. They are readily available for the SB V8s but I can't find any for the 60 degree V6.

I think that I'll start another thread concerning said mod.

Jack

I could go back to what I certainly do not like, the 2.95 X 3.07 which gives a doggy 9.06 1st gear. You have to know when your too high geared and that is doable with the low weight but if your going to shift that way, just stick with the 4.03 'box, Stick with the 3.909 stock rear end, use 2nd to start (2.19??) and end up with a 8.56 to 1 2nd gear. Many people will tell you that this is slightly too tall for their taste and thus the standard V6 'box and standard MGB rear make 1st too low and 2nd too high...

So what about 5th? Switch it out to a 0.5 to 1 overdrive with the stock rear end. You will end up with a 1.95 5th.
If you find a T5 with a 0.63 overdrive and a 3.07 rear end, you will effectively run a 1.93 5th gear.

Since the engines have a w-i-d-e powerband, you can effectively use 2nd, 4th and 5th.

I hope I'm not coming off as a my way or highway kind but have really thought these numbers through quite a bit for the engine series. Honestly, the only thing that gets me sometimes with the package ratio set that I recommend is that the 3.42 with a 3.76 1st can be wound out a couple miles per hour quick (COMPARED to the 3.23) but it does move quicker and gives a better feel to 4th and 5th but for me, this is splitting hairs.

-BMC.

Okay, now I am officially arguing with myself by posting 3X in a row.

Jack or anyone could try this:

Leave the stock rear end in place.
See how 1st gear feels to start out. (yuk- too low ~ speed)
See how 2nd gear feels to start out. (yuk- too high)
See how 4th gear feels (Too low & needs more speed at lower RPMs)
See how 5th gear feels (Feels like where 4th gear SHOULD end up)

By pulling this test and starting with the stock rear end, any tester can get the numbers and feel. I bet many would conclude that my numbers will be close to their own with a car of similar weight, tyre size, engine power band and other similar bits.

-BMC.

p.s. Now if I had 400 lbs Tq, Close ratio would be okay because the tires wouldn't stick in 1st gear no matter the ratio and thus a high speed 1st gear would have little effect on slowing the 0 to 30 MPH pulls.

p.p.s. If I had half the torque ~the lump 1.8L~ my gearing again would change for the overall effect on the car.

I can calculate gear ratios out to twelve decimal points, but that doesn't tell me what it will feel like at my butt. I have a 2.95 first, with a 3.25 rear, for a total of 9.59. With over 300 lbft to play with, it gives me a vicious kick in the behind on take off. It'll knock your teeth loose hitting second. I wonder what it would feel like with a 2.95/4.11 for a 12.12 overall? Would I have to go so easy on the gas to prevent wheel spin that I wouldn't notice the difference? Would I black out from the G-force? Inquiring minds want to know.

Looking on the British V8 website, I see V8 and V6 conversions with rear axle ratios all over the place, from 3.07 to 4.11, with similar first gear ranges. Does that mean about half of them made the wrong choice? Unless you experiment with them all, how will you know you have the "best" choice?

I'm pretty danged happy with the car geared the way it is, but I guess I'll always have this nagging feeling that it could be better. Below is a chart showing the rpm/speed for each gear.

Just for kicks, I redid the chart for a 4.11 rear, keeping the same 2.95 first. I believe it would be livable.

First point: We seem to be neglecting tire size in this equation - it's an important factor.
I'll also say that Dan's ratios are more in tune with my tastes. I have 24" dia rubber, a Ford T5 w/3.35 first and a 3.27 RA ratio....sometimes I wish I could wind it out further in first with a change to a 2.95 first.
As usual, this question will generate a hundred different responses - ultimately, Jack's car should be driven and changes made appropriately if he is disssatisfied with the performance.

Graham,

As usual, you are right on. I could change my tire size to match yours, 225/50/15, and keep my 3.25 rear axle, or I could keep my 215/60/15 tires and change to a 3.43 rear axle, and the results would be the same.

With your tires and my axle, 70mph in 4th would be 3205rpm. With my tires and a 3.43 axle, 70mph in 4th would be 3208rpm. Pretty danged close. Less than 1% difference.

Going from 215/60/15 to 225/50/15 is a pretty good jump - a 1.3 inch difference in tire diameter.

It's late, so I hope my math is correct.

To each, his own.

I have zero interest in a set of 3.07 Grandma gears. I very much like a 2.95 1st gear. If I ever build a rearend, it will have something very close to 3.50 gears. Just works for me.