"T5" means Volvo engine with a certain amount of power, it has nothing to do with the number of cylinders. My 4-cylinder would be a T3 if Volvo bothered to make a badge for it. (The 200hp variant was labeled "T4" however)

Anyway, all that meant was that Ford put a Duratec label on the Volvo engine when it was put in a Focus. Big whoop. They also put the Duratec label on a Mazda engine when put in a Ford.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

FWIW, I came across a Miata shop with a dyno of an unopened 2.5 with the minimum to fit into a 3rd gen MX-5 (Miata intake manifold with a little porting, header, ECU retune) putting out 200hp to the wheels. http://www.good-win-racing.com/Mazda-Performance-Part/61-1506.html for the dyno... 90% of peak torque from something like 2k to 6k RPM, redline out at 7400ish. That's like what, $3-400 for the engine off car-part?

7400 with the loooooong stroke of a 2.5 and stock rods scares me a little. But interesting to know.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

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mekilljoydammit
FWIW, I came across a Miata shop with a dyno of an unopened 2.5 with the minimum to fit into a 3rd gen MX-5 (Miata intake manifold with a little porting, header, ECU retune) putting out 200hp to the wheels. http://www.good-win-racing.com/Mazda-Performance-Part/61-1506.html for the dyno... 90% of peak torque from something like 2k to 6k RPM, redline out at 7400ish. That's like what, $3-400 for the engine off car-part?

My shop mate is going this route with his NC miata. Cheap (relatively) to swap in, and a good bump in power and torque over the 2.0. The rod/stroke ratio is a little whack, but they've proven to be reliable engines.

The Volvo branded part on the Ecoboost was the boost/vacuum check valve.

I'm getting to thinking hard of doing a 'bitsa' rallycross build using a roadrace 1st gen RX-7 shell I have sitting around and maybe a 2.5 so I don't use any of the rotary bits I have earmarked for other uses. No idea what to do for tires yet (those indysport dealies any good?) but figure I can worry about that when I get there.

From what I have seen in person the Indy Sport tires are phenomenal for unpacked dirt.

Of course, I'm also extremely happy with my Black Rockets. I didn't start getting big breakage problems until after I switched to them, after all. They are excellent all-rounders but I want a set of the Indy Sport mud tires, or maybe just two for the back and some tall/narrow Winterforces with heavy application of a heated chisel to turn them into something like "rib" tractor tires since when it is sloppy the most difficult thing is getting steering out of the front end.

Working on the new RX-7, the engine is probably useless. So I am deeply thinking of a 2.5 for the black car and some sort of carbureted 4-port 13B for the new one. Weird that as "rare" as they are, I have an embarassment of useable GSL-SE engine parts and no good 12A parts. And you can still buy new GSL-SE rotor housings from Mazda Motorsports, pretty cheap too. If a 2.5 can make sufficient power at low RPM like that (I consider 7400 to be "low" then that opens the door for using a 5L55 (5R55?) transmission, which due to a quirk in how Ford turned a 4-speed auto into a 5-speed, has a rather close 1-2 ratio split, which IMO means "perfect Rallycross transmission".

And I still want a damn automatic in the car, anyway.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 03/09/2017 08:17PM by Pete.

Huh, the Black Rockets even seem to be more commonly available in 13" too; would mean not having to get more wheels. I was thinking an MX-5 box, either 6 or 5 speed (5 speed is basically just Yet Another Smoothcase box) myself as automatics confuse and annoy me.

I should probably just send you a PM on more specific Mazda stuff.

Quote
mekilljoydammit
Huh, the Black Rockets even seem to be more commonly available in 13" too; would mean not having to get more wheels. I was thinking an MX-5 box, either 6 or 5 speed (5 speed is basically just Yet Another Smoothcase box) myself as automatics confuse and annoy me.

I should probably just send you a PM on more specific Mazda stuff.

We can get 155/70R13 in the F or SG IndySport and 175/70R13 in SG only.

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Grant Hughes

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NoCoast

Quote
mekilljoydammit
Huh, the Black Rockets even seem to be more commonly available in 13" too; would mean not having to get more wheels. I was thinking an MX-5 box, either 6 or 5 speed (5 speed is basically just Yet Another Smoothcase box) myself as automatics confuse and annoy me.

I should probably just send you a PM on more specific Mazda stuff.

We can get 155/70R13 in the F or SG IndySport and 175/70R13 in SG only.

Geez, make it easy why dontcha... if I actually follow through with the rest of the car, I'll give you a call.

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mekilljoydammit
I was thinking an MX-5 box, either 6 or 5 speed (5 speed is basically just Yet Another Smoothcase box)

THANK YOU. I'd been trying to determine that but The Hive came up emptyhanded.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Quote
Pete

Quote
mekilljoydammit
I was thinking an MX-5 box, either 6 or 5 speed (5 speed is basically just Yet Another Smoothcase box)

THANK YOU. I'd been trying to determine that but The Hive came up emptyhanded.

Slight grain of salt in that the part numbers are very slightly different for the internals (probably superceded or suchlike) but the internal diagrams are the same, and if you look at the centersection and mid plate (or whatever you want to call it)

As long as I can put an FB tailhousing on it, we're good.

Allegedly all NC transmissions have triple cone synchros or somesuch on the first four gears. NB only had double cone on 2nd gear. I have a friend who has been rallycrossing for many years on the same 1.6 NA transmission, first with a 1.6, then with a Mazdaspeed Miata engine with slightly excessive power (whatever 13psi makes?) and flat-shift/antilag, and he also dolly tows it with the driveshaft still in. Meanwhile, Goofus blows up smoothcase transmissions left and right behind 13Bs and 12As...

I realized that my Ranger core engine might not yield a timing cover for a 2.5 if the deck height changed. A search for Duratec deck heights brought me to a thread here on RallyAnarchy about Duratecs and while no hard info was gleaned other than 2.0 and 2.3 having different heights, it did come to light that the 2.5 has "stout" forged rods and not powdered metal rods.

Now, I am not an anti-PM rod curmudgeon like some people are who throw them out as a matter of principle - and I have a PM rod out of a 6-liter Chevy that bent into an S without breaking that I keep as a talisman - but I respect that the Duratec PM rods are apparently more like powdered cheese, and I see the 2.5's alleged forged rods as a great reassurance.

And then someone was telling me stories of 2.3 cranks in 2.5 blocks and I have a feeling we had this discussion on another forum.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 2 time(s). Last edit at 03/10/2017 06:41PM by Pete.

2.3 and 2.5 blocks have same deck height. You can use a 2.3 timing cover on a 2.5, and for certain engine swaps you have to.

From a Focus forum:

"The 2.5 and 2.3 blocks are identical other than 1 oil passageway that connect to the head and the bore is larger on the 2.5 block.

The crankshafts have the same diameter main journal bores but the 2.5 uses a larger connecting rod journal.

The 2.5 crank shaft has a 100mm stroke vs the 2.3 94mm to the 2.5 uses shorter rods to compensate. "

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Was just going to say, I'm pretty sure the 2.5 has the same deck height. It has the dumbass full circle to drive balance shaft crank though, but the Ranger 2.3 (not necessarily all the 2.3 cranks, maybe some, I dunno) doesn't have that... and there's Ye Chinese Rods for the 2.3 rod length, and at at least some pistons that are 2.3 pin height and 2.5 bore (Supertech comes to mind) There's a bunch of stuff around on putting the MX-5 intake manifold on a 2.5 with a little light grinding, and so on. Or I had other stuff in mind for that side of things, but check your PMs, I don't want too many people bugging me about it until I have the first couple built and working.

I'm about as sure you can put an FB tailshaft housing on the NC 5 speed as I can be without having actually done it; for reference, the NB Miata 6 speed tailshaft housing fits on the RX-8 box too.

Just a 2018 update. While searching a 2.0 controls pack, i found out that Ford has discontinued it. It has been superceded by a 2.3l Ecoboost controls pack.

Now, the 2.0 controls pack would work directly with a production car 2.0 Ecoboost. When they made the controls pack for the 3.5 Ecoboost, they did it in such a way that you could not use it without the corresponding crate engine. (Something about the fuel rail is completely different, and some other changes) I wonder if the 2.3 is similarly hamstrung so you have to buy the entire $8000 swap. But the controls packs for the 2.3 are available for $1800...

Also, Quad4Rods apparently no longer exists, so beefy transmission options just got a bit narrower in scope. NC 5-speeds are not cheap, but if the input shaft is the same length as NA/NBs, then one could just buy two NC transmissions and keep rotating NA/NB guts behind their front housings.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 07/22/2018 06:30AM by Pete.