Hey, I was wondering if anyone knows what the RWHP is on a completely stock fd?

I'm getting ready to dyno my '94 and I want something to compare it to!!!

Thanks

 

216

 

220 just about

 

Damn, I thought I read they were 255hp stock... I guess dont trust the Victoria British catalog for specs or anything else...!!

 

I think they are talking about power to the rear wheels, counting drivetrain losses.

An example is my wife's IS300. Factory lists the power at 215 or so, but a dyno shows the power to be around 180.

 

Aah, Good point...

 

heres a good question for you guys.What about the auto fd's.Are they putting down the same horsepower at the wheels as the 5 speeds?

 

thanks guys

 

Yes. But the higher diff gears (A: 3.90 vs. M: 4.10) and lower rpm launch, makes the auto FD a little slower in 1/4 mile E.T.

FYI,.. An auto tranny equipped stock FD produces 255 hp at 6200 rpm. The manual tranny equipped stock FD produces 255 hp at 6500 rpm.

 

there is more drive train loss in the auto tranny, so rwhp should be a little bit lower.

 

What documents have you read to support that statement?? I've never come across documentation that indicates auto stock FD rwhp is less than manual stock FD. Thanks.

 

That's because flywheel horsepower will be identical on an auto vs. manual, which is the only horsepower that mazda has quoted. There is more loss with an auto transmission, so there will be less transferred to the wheels, ie- less rear wheel horsepower.

 

Hey, flyboyjuge where are you going to dyno the car at? I would like to see it sometime.

 

My tired old stock motor with downpipe only had 210 to the rear wheels.

 

At our club dyno days, all stock FDs have had 222-227 at the rear wheels. I'd say that's about 20 cars.

 

Were there any Auto FDs in the bunch??

 

i went to ats in columbia...my second turbo didnt spool at all so i only made 166 to the wheels...very dissapointed...

 

I understand the whole drivetrain loss thing.But I still want some hard facts.If anyone has dynod a stock auto fd.Let us know how much power you made at the wheels.Also if the auto tranny makes 255 horses at the flywheel at 6200 rpms isnt that better than having 255 horses at 6500 rpms? It would mean that the power comes sooner throughout the powerband.

 

Where do you see that an auto makes that power sooner? I think you're mistaken, because flywheel horsepower is independant of the type of transmission installed, and aside from the rear housing shape, the engines are identical.

 

I was simply going off of what areXseven was saying.It was meant more as a question.Because I always thought that if the max horsepower comes on sooner in the rpm range its better than if it comes on later.For example the new 2004 honda s2000.They tweaked the power band so you dont have to rev it as high in order to get the most power from it.

 

Im also pondering the idea of changing the rear pinon to either 4.1 or 4.3
Would the car make the same rear wheel horsepower if it had the same differential gearing? Just a hypothesis.Let me know if im right.Stock for stock I mean.

 

I wish I would have known that you were going to be at ATS I only live like 20 minutes away from there.

 

Well, fine...the peak power is lower in the RPM band, but also the peak horsepower number is lower. ie- manual could make 220rwhp@6500 and an auto 195rwhp@6200. An auto has 3.9 rear end, and manual has 4.1 ratio. An automatic by design makes its peak power earlier in the band, so in efforts to push the peak power a bit further up in the band to utilize the rotary's unique revving characteristics, a 3.9 gear was used for the autos. I don't think you make more power with a different gear, it just makes the timing of the peak power earlier or later in the band.

 

um.
My Is300 made 201 @ teh rear wheels when it had 1000 miles on it! And thats an auto!

 

Good god....

1) all dynos will read differently, there is almost no point in comparing results from different dynos unless they are SAE numbers, and even then....

2) an auto tranny has more driveline loss than a manual. Period. An auto FD WILL put less hp to the ground than a manual will. That is the same for ANY auto tranny vs manual tranny car.

3) changing the rear end most certainly affects the ACTUAL power to the ground, assuming the tranny gear ratios stay the same. If you don't know why, go to a tranny how-stuff-works site.

A stock healthy manual FD makes around 215-220 rwhp. If you measure on a colder day, the actual numbers will be higher, which is why only SAE results should be used for comparison -- and even those are faulty when the testing conditions vary significantly from the "standard" conditions.

Also, the above numbers only apply to dynojets, not Mustang dynos or dynapaks.