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gears/intake

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Posted by: 96mark8

sorry i am sure this info has been covered meany times before but i just have to ask.

the first thing i would like to ask is if somone could give me a nice parts list of what i would need to swap a cobra intake in to a gen 1 and how much moeny it would cost in total about . the seconed thing i was wondering is what gears would be best for a mark running a t56,kooks header 2.5 inch all the way down and a cobra intake? and what 1/4 mile times am i looking at with all those mods high 13 low 14 maybe?

Posted by: 96mark8

oh and do i need a cobra R hood to make the intake fit?

Posted by: NateRW21

For a GM T-56 from an F-body, you'd have gearing that looks like:
1st; 2.66:1
2nd; 1.78:1
3rd; 1.30:1
4th; 1.00:1
5th; 0.74:1
6th; 0.50:1

1993 Z/28-firebird"
1st; 3.36:1
2nd; 2.07:1
3rd; 1.35:1
4th; 1.00:1
5th; 0.80:1
6th; 0.62:1
::: W/ G92 AXLE :::
1st; 2.97:1
2nd; 2.07:1
3rd; 1.43:1
4th; 1.00:1
5th; 0.80:1
6th; 0.62:1

GTO, CTS-V, Corvette C5/Z0-6:
1st; 2.97:1
2nd; 2.07:1
3rd; 1.43:1
4th; 1.00:1
5th; 0.84:1
6th; 0.57:1

4R70W ratios are:
1st; 2.84:1
2nd: 1.55:1
3rd: 1.00:1
4th: 0.70:1
Rev: 2.23:1

There you go, with that you should be able to decide.

I'll throw in my own $0.02 though: Avoid the one with the 3.36:1 1st gear; it'll make your launch pretty weak and absolutely require a 4.10 gear set. Actually, with that one... you'd be a slug off the line using 4.10's, might be advisable to shoot for 4:30 or 4:56. Downside to this is, you'd be spinning your engine at a pretty high RPM goin down the highway, and generating a massive amount of heat in your diff (time to install a diff cooler).

If you go with the other listed 1993 F-body trans, 3.73 or 3.90 would give you good launch with an acceptable highway RPM. Otherwise, given the 2nd overdrive ratios on the other versions of the T56, I'd run a 4.10.

The standard F-body version will have a VERY VERY short 1st gear.

If you've not obtained your trans yet, going by gearing alone it seems your best combo would be a T56 from a 93 Z/28-firechicken or the GTO/CTS-V/Vette trans with the 4.10's; it will keep your engine running near the factory highway RPM's but give you a much better launch without making 1st gear virtually useless.

Any other F-body T56 would work well enough with 4.10's, but your first gear will be pretty short. I'd almost order up 3.90 gears to run that trans. 3.90 gears aren't as common as 3.73's and 4.10's, but Motive Gear makes em and this would be a good application for that gear set; giving you just a little more usable 1st gear.

I'm sure someone will add to this...

Posted by: NateRW21

Also, as an added note to those running 4.10's and up or considering the swap...

Keep in mind that when compared to a standard solid axle, your IRS diff holds somewhere in the ball park of less than half the fluid of a solid axle. When you start running lower gears, you generate a lot more heat in that differential. This is something the Cobra R guys figured out when they were burning up their torsen diff's at the track. You might want to consider setting up a diff cooler if you run your car hard. Kits can be had for around $1200... but you can piece together a tube type fluid cooler w/fan (tube NOT plate.. diff lube is too thick to flow through a plate trans cooler with any sort of efficiency), stainless hose, check valve, temp switch and fluid pump for under $500. It's great insurance. I'm installing one on the front diff for my truck in the spring.

Posted by: 93' Blue on blue

You got me a little lost

3.36:1 is the lowest/shortest of all the first gears you listed there, why would it be a slug off the line, requiring extra short rear gears? Or do you mean the 2.66:1? Which is the tallest/highest first gear listed, requiring most rear gear.

Posted by: NateRW21

AHHHH... thanks for pointing that out!!! Apparently I confused myself!

CORRECTION: the trans with the 3.36 1st gear would run very well with a 3.55 rear gear.

Standard F body T-56 (first one listed) would work great with 3.73's

The GTO/CTS-V/Vette and G92 in my view, 3.73's would really be a perfect fit. 3.90's and 4.10's would work too, especially for the GTO with it's .57 6th gear, but you might find 1st gear a bit short (I'd advise you to lean away from the 4.10's with this trans; limit yourself to 3.90's. Think the trans you have now... with 4.55's). Depends on how you want to use it

Posted by: 93' Blue on blue

Gears can be a head ache at the best of times, let alone in these early hours! Lol.

Posted by: NateRW21

Here, I'll crunch some numbers. (these will all be assuming factory tires):

4R70W (3.27:1 rear gear):

Road Speed at a given RPM (1st gear):
1500- 13
3000- 27
5000- 45
Road Speed at a given RPM (4th gear):
1500- 55
3000- 109
5000- 182

Road RPM's at a Given Speed (1st gear):
15MPH- 1113
40MPH- 3894
70MPH- 7788
Road RPM's at a Given Speed (4th gear):
70MPH- 1920

Rear gear change from 3.27 to 4.10:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 22
5000- 36
Road Speed at a given RPM (4th gear):
1500- 44
3000- 87
5000- 145

Road RPM's at a Given Speed (1st gear):
15MPH- 2092
40MPH- 5580
70MPH- 9764
Road RPM's at a Given Speed (4th gear):
40MPH- 1375
70MPH- 2407

stand by, more to come

Posted by: NateRW21

T-56, standard F body; first listed (4.10:1 rear gear):

Road Speed at a given RPM (1st gear):
1500- 6
3000- 23
5000- 38
Road Speed at a given RPM (6th gear):
1500- 31
3000- 122
5000- 204

Road RPM's at a Given Speed (1st gear):
15MPH- 1960
40MPH- 5226
70MPH- 9146
Road RPM's at a Given Speed (6th gear):
70MPH- 1719

Rear gear 3.90:

Road Speed at a given RPM (1st gear):
1500- 12
3000- 24
5000- 40
Road Speed at a given RPM (6th gear):
1500- 64
3000- 129
5000- 215

Road RPM's at a Given Speed (1st gear):
15MPH- 1859
40MPH- 4958
70MPH- 8677
Road RPM's at a Given Speed (4th gear):
40MPH- 932
70MPH- 1631

Rear gear 3.73:

Road Speed at a given RPM (1st gear):
1500- 13
3000- 25
5000- 42
Road Speed at a given RPM (6th gear):
1500- 67
3000- 134
5000- 224

Road RPM's at a Given Speed (1st gear):
15MPH- 1783
40MPH- 4754
70MPH- 8320
Road RPM's at a Given Speed (4th gear):
40MPH- 894
70MPH- 1564

Posted by: NateRW21

T-56, 1993 Z/28-Firebird; second listed (4.10:1 rear gear):

Road Speed at a given RPM (1st gear):
1500- 9
3000- 18
5000- 30
Road Speed at a given RPM (6th gear):
1500- 49
3000- 99
5000- 164

Road RPM's at a Given Speed (1st gear):
15MPH- 2476
40MPH- 6601
70MPH- 11552
Road RPM's at a Given Speed (6th gear):
70MPH- 2132

Rear gear 3.90:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 19
5000- 32
Road Speed at a given RPM (6th gear):
1500- 52
3000- 104
5000- 173

Road RPM's at a Given Speed (1st gear):
15MPH- 2349
40MPH- 6263
70MPH- 10961
Road RPM's at a Given Speed (6th gear):
40MPH- 1156
70MPH- 2022

Rear gear 3.73:

Road Speed at a given RPM (1st gear):
1500- 10
3000- 20
5000- 33
Road Speed at a given RPM (6th gear):
1500- 54
3000- 108
5000- 180

Road RPM's at a Given Speed (1st gear):
15MPH- 2252
40MPH- 6006
70MPH- 10510
Road RPM's at a Given Speed (6th gear):
40MPH- 1108
70MPH- 1939

Rear gear 3.55:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 21
5000- 35
Road Speed at a given RPM (6th gear):
1500- 57
3000- 114
5000- 190

Road RPM's at a Given Speed (1st gear):
15MPH- 2137
40MPH- 5700
70MPH- 9974
Road RPM's at a Given Speed (6th gear):
40MPH- 1052
70MPH- 1841

Rear gear 3.27:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 23
5000- 38
Road Speed at a given RPM (6th gear):
1500- 62
3000- 124
5000- 206

Road RPM's at a Given Speed (1st gear):
15MPH- 1974
40MPH- 5265
70MPH- 9214
Road RPM's at a Given Speed (6th gear):
40MPH- 972
70MPH- 1700

NOTE: this trans would work with the factory gearing on an LSC!!!!!

Posted by: NateRW21

T-56, 1993 Z/28-Firebird, G92 axle; Third listed (4.10:1 rear gear):

Road Speed at a given RPM (1st gear):
1500- 10
3000- 21
5000- 34
Road Speed at a given RPM (6th gear):
1500- 49
3000- 99
5000- 164

Road RPM's at a Given Speed (1st gear):
15MPH- 2188
40MPH- 5835
70MPH- 10211
Road RPM's at a Given Speed (6th gear):
70MPH- 2132

Rear gear 3.90:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 22
5000- 36
Road Speed at a given RPM (6th gear):
1500- 52
3000- 104
5000- 173

Road RPM's at a Given Speed (1st gear):
15MPH- 2076
40MPH- 5536
70MPH- 9688
Road RPM's at a Given Speed (6th gear):
40MPH- 1156
70MPH- 2022

Rear gear 3.73:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 23
5000- 38
Road Speed at a given RPM (6th gear):
1500- 54
3000- 108
5000- 180

Road RPM's at a Given Speed (1st gear):
15MPH- 1991
40MPH- 5309
70MPH- 9290
Road RPM's at a Given Speed (6th gear):
40MPH- 1108
70MPH- 1939

Rear gear 3.55:

Road Speed at a given RPM (1st gear):
1500- 12
3000- 24
5000- 40
Road Speed at a given RPM (6th gear):
1500- 57
3000- 114
5000- 190

Road RPM's at a Given Speed (1st gear):
15MPH- 1889
40MPH- 5038
70MPH- 8817
Road RPM's at a Given Speed (6th gear):
40MPH- 1052
70MPH- 1841

Posted by: NateRW21

T-56, GTO/CTS-V/Corvette C5/ZO-6; Fourth listed (4.10:1 rear gear):

Road Speed at a given RPM (1st gear):
1500- 10
3000- 21
5000- 34
Road Speed at a given RPM (6th gear):
1500- 54
3000- 107
5000- 179

Road RPM's at a Given Speed (1st gear):
15MPH- 2188
40MPH- 5835
70MPH- 10211
Road RPM's at a Given Speed (6th gear):
40MPH- 1120
70MPH- 1960

Rear gear 3.90:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 22
5000- 36
Road Speed at a given RPM (6th gear):
1500- 56
3000- 113
5000- 188

Road RPM's at a Given Speed (1st gear):
15MPH- 2076
40MPH- 5536
70MPH- 9688
Road RPM's at a Given Speed (6th gear):
40MPH- 1063
70MPH- 1859

Rear gear 3.73:

Road Speed at a given RPM (1st gear):
1500- 11
3000- 23
5000- 38
Road Speed at a given RPM (6th gear):
1500- 59
3000- 118
5000- 196

Road RPM's at a Given Speed (1st gear):
15MPH- 1991
40MPH- 5309
70MPH- 9290
Road RPM's at a Given Speed (6th gear):
40MPH- 1019
70MPH- 1783

Posted by: NateRW21

T-56 in order as previously listed, my choice gearings:

First: 4.10 (note, first gear speed at 1500 RPM is incorrect, should read 11mph). Although I believe 4.30 would be a better option, I didn't crunch the numbers on it... and a 4.30 would certainly require a diff cooler and a touch of clearancing on the case when the R&P are installed (anything OVER 4.10 requires a bit of clearancing)

Second:3.55 over-all, 3.73 and 3.90 for strip. 3.27 (factory LSC) would be close to factory first and last gears.

Third: 3.73 over-all; 3.55 is a touch lower than stock, 3.90 and 4.10 would be great strip gears.

Fourth: 3.90 over-all; 4.10 for street/strip duty, more strip than street.

Posted by: 96mark8

wow thanks for all the info nate. I have not bought the trans yet i am going to the junk yard next weekend i was wondering thow what about a t56 out of a 03 cobra how would that work out? cuz that was what i was going to get originally?

Posted by: NateRW21

I don't personally know this for sure, but the reason I didn't include the gear ratios for the cobra (it too has it's own gear set) is because I believe the location of the gear shifter would be too far forward. From my own research, the most likely direct drop in would be the F-body or GTO trans. GTO is apparently a touch further back yet than the F-body.

The thing with the cobra trans is, if you've ever sat in one... the shifter is pretty much directly below the center console/dash. It really is not located very well as you've got to reach for it. I'd suspect, as stated before due to my research and my own observations that a Cobra T-56 would have the gear shifter in a totally different location than it currently is in.

Something else to consider is that the Cobra T-56 won't be as easy to come by, or as cheap as an F-body T-56.

I'd try to find the T-56 from the 93 Z/28-firechicken (non-G92 axle) as a first choice. You'd be able to run 3.55's or 3.73's (depending on desired use), which will keep your drive-shaft speed down and minimize vibrations, and will help ensure your diff doesn't build up too much heat.

Second choice would be the G92 axle.

Of course, that is providing those transmissions are a good match to your factory shifter location (going to need to measure!). Obviously if you need it further back yet, then the GTO trans is your best bet (acceptable gear set with correct shifter location).

The reason I crunched all those numbers is to illustrate how different 1st and 6th gear ratios require a different rear gear ratio. IMO, running the 4R70W with 4.10's on the street (read, highway speeds) is not very practical due to the high RPM's in 4th gear. This is where a 5-6 speed really earns it's keep; if you noticed, most of the T-56's will give you performance very similar to the 4R70W with less rear gear, but won't kill your top end (and mileage/durability). It's actually possible to get the same performance advantage of a 4.10 w/ 4R70W and the mileage of a 3.27 w/4R70W running a 3.73-3.90 on a T-56. And all of this for what I imagine to be a similar weight. Really, hard to go wrong. Plus a factory T-56 should be capable of handling 500HP for quite a long time. Throw that kind of power into a factory 4R70W and watch the shrapnel fly!

Posted by: 96mark8

yea i was originally planning on geting a t56 out of a cobra and use a f-body tailshaft or gto but u are right i think i could pick up a f-body t56 for less then the cobra t56. well i have this week to think about it. thanks for your help.

Posted by: 96mark8

o yea do you know what year f-bodys have a t56?

Posted by: NateRW21

off the top of my head... I'm not sure. I'll check into it tomorrow and let you know what I find out. I'd venture to guess though that virtually all 6-speed equiped F-Body's would be running the T-56. Although I could be wrong... GM has been known to do stupid things just like ever other US manufacture; entirely possible they could have ditched the proven T-56 for something else.

Posted by: ONEBADMK8

Diff cooler? LMAO! No way never in a million years would we need that in our cars, save the loot and put it elsewhere in the vehicle. I have been running 4.10's for 10 plus years now with NO real significant more then normal breakdown of the gear oil.

Posted by: NateRW21

Quote:

Originally Posted by ONEBADMK8

Diff cooler? LMAO! No way never in a million years would we need that in our cars, save the loot and put it elsewhere in the vehicle. I have been running 4.10's for 10 plus years now with NO real significant more then normal breakdown of the gear oil.

I think you might have missed something in my post; either that or I wasn't clear enough.

I suppose I wasn't clear enough... Cobra R cars don't see drag duty; they see plenty of autocross, GT class and modified GT class racing. This is what I was referring to when I made mention of driving their cars hard.

What you've got at work here is elevated diff temps due to the gearing and hard use which, just like in a transmission will burn up your limited slip diff (this correlation is due to both using friction materials/plates).

This issue at hand is not burning the fluid and breaking it down (although, when going higher than 4.10's with an IRS, you are approaching this issue)... the issue is the early demise of the limited slip. Fortunately, drag duty isn't nearly as rough on a diff as a track with twisties.

Again, as stated before... if you drive your car hard (that means truly drive it, not accelerate in a straight line).

To illustrate my point, although the application is rather different, the parts are all the same. I put 4.10's in my F-150 with an eaton E-locker in the rear and the Tracloc from the rear, rebuild and put in the front. I'm going to be pulling my front diff and replacing the tracloc with an auburn Elect'ed (limited slip electric locker). Why? Well for the obvious benefit of having a locker front and rear... while still being able to run limited slip/open for duty in the white puffy stuff. BUT, had my tracloc not BURNT UP in the front diff, I'd leave well enough alone. Of course, my 35" tires help to hurry along the destruction, but unlike a rear diff, the front diff only sees duty when the conditions are as such where traction is limited (otherwise, one axle disconnects from the diff and then both free-spool). So with this example, you can see how when really used hard, a diff cooler is almost a requirement. I'll also be installing one when I put in the Auburn diff (as mentioned before, in the spring).

How many of you really drive your Mark hard... I don't know. When I get a mark, I'd like to autocross it; granted I'll have to do plenty of structural reinforcement, but that's the goal; to spank on guys in much smaller, agile cars with an "old man's Lincoln". And you can bet she'll get a diff cooler...

Posted by: NateRW21

All V8 F-bodies from 93-up came with the T-56.

Posted by: NateRW21

A bit more info:
Bell-housing to shifter distance:
93-97 F-body: 28.3"
98/99 F-Body: 29.4"
4.6L Mustang: 26.4"

Bell-housing depth:
93-97 F-body: 4.9"
98/99 F-Body: 5.5"
4.6L Mustang: 5.3"

For further info...
2000 Cobra R, 03-04 Cobra T-56 (99, 01 were not T-56's)
1st: 2.66:1
2nd: 1.78:1
3rd: 1.30:1
4th: 1.00:1
5th: 0.79:1
6th: 0.63:1
Plus side to the above is it would work well with 3.73's, downside is sourcing an F-body tail section and the scarcity of that trans in the junkyard.

I would still look for the 93 Z/28 or G92 axle trans. Otherwise, run the F-body T-56 with 4.10's. For both, just pick up a bell-housing for the 4.6L.

Posted by: 95sc

IIRC if you want to run GM t-56 behind 4.6 you have to get an aftermarket bell housing and I think they run around $500 . Stock 98+ 4r70w will hold 500hp no problem,my brother has close to 100K miles and probably around 200 passes at the track on his stock trans.If you put manual trans behind 500hp engine in our cars you'll be braking drive train parts like crazy. IRS suspension and manual trannies hate each other specially in heavy and higher hp cars.

Posted by: 96mark8

thanks for all info i think i will end up running a cobra t56 with a 98 f-body tailshaft because the t56 out of the cobra is cheaper then out of an f-body for some reson and try some3.73's. and if the shifter still won't get far enough back i guess i will have to build a shiftbox

and i will fix the problems as then come. i will put up some pick of how the project comes out when done i will be do in about mid march i think.

Posted by: NateRW21

awesome, I'll be very interested to see the progress!!! I've shocked the cobra trans is cheaper!!!

Did you end up snagging it from a junk yard?

Do a detailed write up on it; it's something that when I get a mark, I think I'll do... and things of this nature are much easier when someone else has done all the trial and error for you! :-D

Posted by: 96mark8

Quote:

Originally Posted by NateRW21

awesome, I'll be very interested to see the progress!!! I've shocked the cobra trans is cheaper!!!

Did you end up snagging it from a junk yard?

Do a detailed write up on it; it's something that when I get a mark, I think I'll do... and things of this nature are much easier when someone else has done all the trial and error for you! :-D

yea i was shocked too the cobra trans is $300 cheaper then an f-body trans. and yes it will be coming from a juck yard i guess they are commen cuz the juck yard i am getting the trans from has 4 more cobra trans and only one f-body. when i am all done i will try to write a nice step by step manual and parts list with a few picks

. I will aslo try to keep this treard updated on the progress! thanks for all your help nate

Posted by: NateRW21

If you don't mind me asking, how much are you getting it for?

And let me stress how important it is you specify it be from an 03-04 cobra or 00 Cobra R (considering only 200 were made, good luck on that.) The earlier SN95 Gen II cobras ran the T-45 (96-99) and TR3650 (2001). Just incase you weren't aware.

Posted by: 96mark8

yea it is a out of a 04 cobra with less then 20000 miles on it for $1500 with the bellhouseing.

Posted by: 96mark8

I went to the junkyard last week and picked up my t56. this weekend i bolted it on to the engine and did a quick test and as predicted the shifter is about 5 inchs to far forward from the stock shifting hole in the consle

if i can get about 3 more inches i could just cut and mod the consle and i think it would not look that bad. but of corse if i could get 5 inches that would be perfect. in another thread hear a guy said that you could get the shifter back 3 more inches about with a GTO shifter and other 2 with a GTO tailshaft. but my question is can put a GTO shifter on a cobra tailshaft? because this project is getting pricey real fast and a GTO tailshaft would cost anther $300 dollers about.my other question is is wear is the reverse gear on a t56? i think it is in the top right but i dont know if you have to push down or pull up in the shifter to get it in reverse?

Posted by: MediumD

IIRC the T56 is like this:

1 3 5 R
2 4 6

I don't remember anything about pushing/pulling, but it's been awhile since I've driven a T56 Cobra.

Remember to keep us posted

Posted by: 96mark8

Quote:

Originally Posted by MediumD

IIRC the T56 is like this:

1 3 5 R
2 4 6

I don't remember anything about pushing/pulling, but it's been awhile since I've driven a T56 Cobra.

Remember to keep us posted

thanks for the help i will put some pics up before final assembely

Posted by: 95sc

Quote:

Originally Posted by MediumD

IIRC the T56 is like this:

1 3 5 R
2 4 6

I don't remember anything about pushing/pulling, but it's been awhile since I've driven a T56 Cobra.

Remember to keep us posted

That's correct and you don't need to do anything special to go into Reverse in Cobra T-56. I remember my buddy's Focus you had to pull up on the shifter boot to get into the reverse.here is the picture of shifter in my GT with Cobra t-56 trans .

Posted by: lsc8

did you ever figure that shifter lenght out? I have been tossing the idea around as well

Posted by: 96mark8

Quote:

Originally Posted by lsc8

did you ever figure that shifter lenght out? I have been tossing the idea around as well

it is kind of hard to explain without a picture.i have an idea of what i am going to do. i am just waiting for the weather to worm up so a can test how far back i have to put my shifter but i will deffenally post pics on this thread of the shifter and how it looks when i am done with it before i put it in the car. that will probely be in like a month because i am really busy right now and this project has been put on stand by.

Posted by: poniesviii

Any progress? Interested in info as well.

Nate, thanks for all the time on the gears.

Posted by: 96mark8

Quote:

Originally Posted by poniesviii

Any progress? Interested in info as well.

Nate, thanks for all the time on the gears.

yes got the car running this week it is not all done yet still has stock gears and i need to build a shifter but for now i am just enjoying it!
i poested a couple pics in this thread if you scroll down!

http://www.lincolnvscadillac.com/showthread.php?t=43701

P.S when all done i will post a thread to answer all questions and give detail on the swap!

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