Checked Compression, now what?

ford20

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I'm going to be boosting later this year so I decided to run a compression test on my 96 GT to see how the motor is. Everything seems fine to me, all cylinders were between 145-155psi. Should I bother with a leak down test, or is there anything else I should check to ensure I'm working with a healthy motor? Car runs good minus a bouncy idle and slow rpm drop that I am trying to pinpoint and diagnose.
 

96blak54

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Seems good! Just dont go overboard with boost on your stocker. 100rwhp is fine 350-375 area any more than that the stock components start to become brittle and break. Also a dyno tune is mandatory. Just forget about force inducing if your going to use a mail ordertune.
 
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ford20

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I will be using a Snow Performance meth kit on about 10lbs. Bama tuner, custom dyno tune. Hoping for around 420whp. Custom turbo kit, possible PI head swap
 

96blak54

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All this on stock pistons and rods? If you plan to destroy the stock engine then by all means have at it. The stock internals will be very unhappy about the 400+ rwhp. Do yourself a favor and replace the rod piston combo now before you destroy it all, leaving you to build completely new.
 
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ford20

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I've seen a fair amount of 2v cars making 400-425whp. I'm not claiming to know it all by any means but I've done quite a bit of research before posting this. I know those numbers are pushing it but theres even builds with 450-490whp (obviously these are bound to go boom) that are really pushing it...
 

96blak54

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Reasearch is good and you're right, their are plenty of 2v's stock bottom ends holding out. I assume you know someone with a similar set up?
 
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ford20

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I would be happy with 400whp.

What do I need to look out for next in the drivetrain area? Aside from clutch...

Thanks guys
 

Willis_98GT

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I would be happy with 400whp.

What do I need to look out for next in the drivetrain area? Aside from clutch...

Thanks guys

Plenty of formulations will come into play when you start making good power with these cars.

Do you plan on visiting the track often? using slicks? the splines on your axles will fail quickly.

Shifting aggressive? The forks are made of glass in the t-45s (not literally) but they fail quite easily, remember the trans is only designed to handle the stock 185whp.

A clutch at the least will have to be a must. i run a centerforce stage 2 and have been using it for almost three years with no problems at all with my setup with a built transmission.
 

96blak54

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I have to disagree with the trannies design handling 185whp. If this is the case then they over designed them cause ive seen upwards 500rwhp with holeshots on them unbuilt. Now for the shift forks, I agree. They definitely didnt account for us monster armstrong shifters.
 

Willis_98GT

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I have to disagree with the trannies design handling 185whp. If this is the case then they over designed them cause ive seen upwards 500rwhp with holeshots on them unbuilt. Now for the shift forks, I agree. They definitely didnt account for us monster armstrong shifters.

Well just keep in mind thats what these things make stock.

Theres tons of threads on here discussing how weak that transmission is. I know of several Veteran members on this forum who have split casings in half.. spun shafts.. bent forks etc.

Its a very weak point on these cars. I'm just lucky because mine is built.

My first t-45 i broke the 3/4 fork with nothing but a off road pipe and intake/gears. 75k

If he could find a deal on a t-56 he would never have to change the transmission again. and pick up 5-6mpg +-
 
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ford20

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I will be running drag radials (Nitto 555r), no slicks. Mostly highway pulls, not from a dig or shifting super aggressive. I am looking towards a Ram PowerGrip HD and nodular iron flywheel, with new shift fork. For the moment, I will have to stick with my t-45.

I'll be looking for some good axles and a driveshaft to upgrade, so I am open to suggestions. Thanks for the help
 

Willis_98GT

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I will be running drag radials (Nitto 555r), no slicks. Mostly highway pulls, not from a dig or shifting super aggressive. I am looking towards a Ram PowerGrip HD and nodular iron flywheel, with new shift fork. For the moment, I will have to stick with my t-45.

I'll be looking for some good axles and a driveshaft to upgrade, so I am open to suggestions. Thanks for the help

The driveshaft isn't necessary to upgrade, but you can always do a aluminum to free up Rotational mass, thats always your #1 goal

as far as axles you can always do a 31 spline upgrade. i know it "sounds" stupid going from 28 splines up to 31 but theres a world of difference.

many companies manufacture them, heres a few key elements to the rear end stuff.

1. Your rear end is 100% compliant with a 99/04 mustang gt too for those that don't know the axles are a inch longer. so if you're ever looking to space your rear wheels/tires swapping this rear into your car will make that process safe. instead of rolling dice with wheel spacers.

2. The 2003 cobra differential is 31 splines, so you may have a better chance to pick up one of these in a parts shop/ebay/craigslist blah blah easier then going out and grabbing a 31 spline differential from a aftermarket supplier.

also consider upgrading the clutch packs while you're doing the differential, the 03 cobra also uses a better clutch design for the differential. All of these little things add up in the long run.

Pull the rear, build it, do it once, do it right.

:headbang:
 
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ford20

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OK thanks, I will have to look more into the 31 spline swap. Some of this stuff is a new world to me (coming from FWD 4cyl cars) so excuse my ignorance :)

A new limited slip and some Mosers would be nice. Then time for some gears
 

Willis_98GT

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OK thanks, I will have to look more into the 31 spline swap. Some of this stuff is a new world to me (coming from FWD 4cyl cars) so excuse my ignorance :)

A new limited slip and some Mosers would be nice. Then time for some gears

The gear decision is up to you, its all about how you drive, want to drive etc.

a good rule of thumb is not to fear the gear as some put it on here.
 

96blak54

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Well just keep in mind thats what these things make stock.

Theres tons of threads on here discussing how weak that transmission is. I know of several Veteran members on this forum who have split casings in half.. spun shafts.. bent forks etc.

Its a very weak point on these cars. I'm just lucky because mine is built.

My first t-45 i broke the 3/4 fork with nothing but a off road pipe and intake/gears. 75k

If he could find a deal on a t-56 he would never have to change the transmission again. and pick up 5-6mpg +-

Im sorry, not trying to whore this thread out and im not trying to argue your points, but yes the first generation of t45's were on the "sloppy" side and not built tight enough to with stand themselves. They may have been behind a turd of an engine, but I assure you they are not the junk you imply. This said when built correctly the first gens(borg warner) t45's can withstand equally what the latter generation(tremec)can handle and honestly, you will have a trouble time posting proof about "internally" broken t45's from 600-less rwhp. The inputshafts give out WAY before the internals.

Also....the t45's week point is the shifting linkage/components itself and horse power has nothing to do with its destruction. An over throwing shifter and poor design shift forks are to blame. Armstrong force shifting is what kills forks.

Rebuilding a t45 is embarrassingly easy to work on and any mechanically level individual with attention to detail can bullet proof build up one with the exception of a stronger input shaft and machined forks. ....Iirc one only needs like 5-6 tools to do a rebuild and the special tool, eaton lock ring pliers, can be picked up at Orielys

And i agree ..yes a t56 is 100% way to go. Again not trying to dispute or degrade your knowledge, just offering info.

One main reason most want a t45 over a t3650(most new edge) is shifting quality. The t45 is nowhere notchy like the t3650 and the t45 is lighter.
 
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ford20

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When the funds allow, I will probably go with something like the pro motion 700+hp T-45 for $2k rather than a stock T-56. Sound like a bad idea? Once its time for a new motor I'm wanting about 750whp so might as well prepare.
 
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ford20

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What about replacing head gaskets and head studs?

Also, I was reading a thread yesterday where a guy blew his stock 2v npi intake mani...should this really be another concern of mine?
 

Willis_98GT

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Im sorry, not trying to whore this thread out and im not trying to argue your points, but yes the first generation of t45's were on the "sloppy" side and not built tight enough to with stand themselves. They may have been behind a turd of an engine, but I assure you they are not the junk you imply. This said when built correctly the first gens(borg warner) t45's can withstand equally what the latter generation(tremec)can handle and honestly, you will have a trouble time posting proof about "internally" broken t45's from 600-less rwhp. The inputshafts give out WAY before the internals.

Also....the t45's week point is the shifting linkage/components itself and horse power has nothing to do with its destruction. An over throwing shifter and poor design shift forks are to blame. Armstrong force shifting is what kills forks.

Rebuilding a t45 is embarrassingly easy to work on and any mechanically level individual with attention to detail can bullet proof build up one with the exception of a stronger input shaft and machined forks. ....Iirc one only needs like 5-6 tools to do a rebuild and the special tool, eaton lock ring pliers, can be picked up at Orielys

And i agree ..yes a t56 is 100% way to go. Again not trying to dispute or degrade your knowledge, just offering info.

One main reason most want a t45 over a t3650(most new edge) is shifting quality. The t45 is nowhere notchy like the t3650 and the t45 is lighter.

Yeah man i agree with you, and i don't take anything you say negatively.

all in all i wish i would have just done a t-56. i just need that sixth gear lol HWmpgs..
 

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