You have to understand this isn't the K series. The market for the J is just starting to open up now, so things are expensive. Evans Tuning built a 3.7L and made 400hp from 6500 to 8k. I emailed them about it and I was told they are using the J32a2 heads and that they will be doing some R&D for new J series parts. I didn't ask for a time frame, but at least TB Motorworx and now Evans Tuning are getting the ball rolling.

 

400 WHP or crank? Do they have any public info on it? That is impressive making 400 HP @ 6500 rpms. I'd like to see the graphs and specs if they have it available.

 

I Thought is was a j36? 14:1 compression? Also the 3.55 fd?

 

It's on their Facebook page. You're right, it's a 3.6 with 14:1, yea. I believe they are using the 3.55 FD as well. Damn thing revs all the way to 8k and the HP doesn't drop off at all.

 

Wait what... they are already using the 3.55 FD? That means they already had one redrilled then....

 

Andy what all does that include? Differential assembly and countershaft?

 

and oil pump gear

 

Thanks for bringing this to my attention.

The oil pump is driven by the ring gear, so any ring gear change should also include the oil pump drive gear that matches the ring gear.

 

New differential/ring gear assembly for 8th gen Accord (3.55):



This basically sucks. There are 14 bolts. Re-drilling for the 12 bolt pattern may not be possible due to many overlapping holes.
Why couldn't Honda make it easy for us?

 

405whp from 6500 to 8000, which is very impressive.


Sigh, that's really annoying. Usually Honda DOES make it easy, yet for the only trans that doesn't have an easy Final Drive option they do this? UGH!

 

On a positive note, all critical dimensions are the same as the 3.286 ring gear, so it's a direct swap aside from the bolts. I put the old FD gear on the new differential and 2 holes line up, so 10 would have to be drilled. Looks like it might be feasible but I'll have to get an expert opinion from a machinist.

I think it's odd that the 3.286 gear has 12 bolts, the 3.55 has 14 bolts and the 3.842 has 16 bolts. Each one is different.

 

I may do this this winter. Especially now that im running 275s on all 4 corners.

 

You guys doing your FDs, any plans or any way to correct the speedo to match?

 

I emailed Doug at hondata, and they said they would look into it. He said it would not be a priority though, because Sonnick and I have been the only ones to request it. I have a dakota digital correction box, but I do not know how many pulse per mile that gets sent to the ecu and the speedo itself. This is the info dakota needs to help me set the box correctly

 

Yea I emailed Doug as well but got no response. I doubt this will be available unless more people order the FD.....which, may be tough considering Acura doesn't manufacture the part anymore.

 

The speedo is electronically controlled? Not mechanically?

 

Yes sir. There is a countershaft and a main shaft speed sensor, and both are magnetic pickups that send signals to the ECU.

 

This is funny. I was just thinking about this the other day, after my last road trip... but I want to go the other way.
I want a final drive in the high 2's, rather than what I have. Get the revs down slightly at cruise- maybe 2000 at 70mph, closer to the auto ratios. I'm sure I'd pick up 1-2mpg easily.

 

^^

You want to make your car accelerate slower to see a ~6% improvement in fuel economy? I could buy that logic if this was a free mod, but this is a minimum $2000 parts and labor ordeal. At 15,000 miles driven annually at 25 mpg, and gas at $4 a gallon, if you saw a 1.5 mpg increase, you'd save $144 a year. I'm just not seeing the logic.

 

^ what he said

just get a civic it gets 40mpg all day

 

I didn't email, but I did bump the thread on Hondata forums about this. I would love to run the 1/4 just that much quicker.

 

Ok, dumb question - so the offset on the speedo would be the differences in speed listed on the previous page here, at the shown RPMs (6800-7300)? Or is there more to it?

For example, if the speedo reads 60mph with the 3.55, how fast are you actually going?

And is there any offset on the tach or does it continue to show accurate engine RPM?

This would be awesome without losing speedo / tach accuracy.

 

I should be around 300-310 at the wheels after I'm all done, all motor / cams / tune, which is around ~350 crank. Would you recommend the 3.55 or 3.8?

 

No affect on the tach, only the speedo. The difference in speed should be about 8% for the 3.55, since that is the difference in ratio.

 

For what it's worth, I don't think absolute power matters as much as how it's made. Naturally aspirated with a narrower power band is going to need the deeper gears more. Turbocharged with a fat powerband won't be so gear dependent.

 

In order to calculate my speedo 'error,' I divided the new FD by the stock FD and subtracted the quotient of my current and stock tire size.

(Current FD/Stock FD)-(Current tire size/Stock tire size)

As follows:

1+(3.842/3.286)-(26.31/25.46) = 1.135817. So my speedo is ~13.58% off. The FD itself is a 16.92% difference, but when you take into account your tire size, it corrects it fully.

FamilyGuy: The 3.84 may be the better option, especially if you plan to rev higher with aftermarket cams. If not for speed alone, the increased pleasure of the extra torque over the whole RPM range is excellent. The 3.55 would be the best compromise between the two, so it really comes down to what you want. I have a 3.0 so my torque is relatively limited as it is compared to the 3.5.

I have an appointment on Saturday to have my cutout installed so regardless of whether or not I get DRs in the next couple weeks, I will be making a trip to the track. So hopefully I will be able to put the question of "does it really make a difference at the track?" to rest.

 

12's car!!

 

^ Certainly not on street tires.....we'll see what happens. I'll go within the next month or so.

 

I agree that the absolute power doesn't matter as much as how it's made. To this regard, I always thought turbos love long gears and NA shorter gears in comparison. I could be wrong.

When you say it's going to need the deeper gears more, do you mean the longer gears, as in the stock ones or maybe the 3.55s, over the 3.84s?

I'm confused. You said the 3.84 was good for those under 320hp. I'll be under 320hp at the wheels but over 320hp at the crank (all estimated).

I know the fat ~3700lbs sport sedans these days manage to be quicker and land in the 13s not only due to the extra hp of a larger 3.7L, but also due to gearing, and I know the FD in our manual TLs is a bit long.

I also know that 6th gear in my car is pretty much useless other than as an overdrive or economy gear, and even 5th gear is somewhat useless this way as well, because 4th tops out at over 120mph, which is plenty fast for the street. The thought of shortening the gears through the FD is appealing, to make the car faster and get some (fun) use out of 5th. I need to be careful though, because the more power I add and weight I remove, the more that the bottom gears feel shorter and lose traction at WOT. I already have to roll the throttle in 1st gear otherwise the tires just spin. I don't mind that in 1st gear but would love to be able to go WOT in 2nd gear and up without losing traction, assuming decent street tires, OEM diameter, just a little bit wider like a ~245. Trying to find that magical balance of performance and usability for a daily driver (with a slight lean towards performance ).

I'd love to jump on that FD buy at v6p, but I don't know enough about gear changes to know what I'm doing beforehand or what the end result will be, though the 3.55s do sound attractive as a safe option, but that's not what the group buy is for right...that and I def want a correct speedo. Looking forward to your track results

By the way, the stock gears right now keep the car in vtec range when you shift near redline. How will the FD ratio changes affect this? Will the car still shift from ~6800RPMs down to ~5k on each upshift?

 

If I recall correctly, changing the final drive won't change that. The final drive may change the speed at which you shift, but the rpm drop is dictated by the transmission gearing, hence Honda's claim of a 'close ratio' transmission.

I'd like to know what the car is taching at 80mph with the 3.80s in 6th. I think anything above 3000 is unacceptable and that's pushing it a bit.

 

^ Exactly right. The FD doesn't change the gearing itself, only the final MPH of each gear. I don't know how to explain it because it doesn't seem to make sense: How could each gear be shorter yet the RPM not change? It has to do with the number of rotations of the transmission in regards to the crank I believe, but I'm not positive and cannot explain it.

FamilyGuy: By the sound of it, the 3.84 would be perfect for you. It sounds like you want a solid daily driver that has the ability to rip it when your foot calls. Now....I got the LW Flywheel at the same time as the FD, so I can't speak SOLELY on the FD itself; but, it's AWESOME. The car gets through the gears much quicker and it's a blast to drive. I'm confident in saying it's the best mod I've done to the car. In essence, you are increasing torque by the % difference of gearing, which would be equivalent to ~17%. My car basically feels like it has 230*117% lb-ft of torque, which = 269 lb-ft. And the difference is felt at literally every RPM, which makes the car so much more fun to drive.

The '320whp' number I threw out before was just a number, really. I hate cars put it perfectly in saying that an all motor car with a 'narrower powerband' (compared to FI) will utilize the FD better than a boosted car. Even some K hatches that weigh next to nothing and make 300+whp use higher than factory gearing, so take my '320' number lightly.

Our stock gearing is perfect for boost, but for the power level we are seeing all motor, it just doesn't do the trick. The torque multiplication of the 3.28 just doesn't cut it for us. This mod really wakes the car up. And IIRC at 60mph I'm at ~23xx RPM and at 80 it's JUST over 3K, like 3050 RPM or so. In terms of highway cruising, it's about 350-400RPM higher than stock. Take it how you will, but I don't think that's bad at all

 

I'm surprised nobody mentioned this yet...

The SH-AWD 6MT has a .69 ratio 6th gear. The other 6MTs have a .771 ratio 6th gear. Wouldn't it be nice to swap 6th gear? Yes, it would.

The gear that goes on the countershaft appears to be the same dimensions, but the gear that goes on the mainshaft is definitely different. Looks like it can be modified to work though. I'll know more once my trans is apart and I can compare the gears.

 

That's exactly what I want down to a T, couldn't have said it better myself.

I think you just sold me on it. I'll try to find that buy thread on v6p and sign up for it. Don't think I'll install it without the speedo correction though, but at least I add one more to the effort.

ps: I also have a LW flywheel, and a LW crank pulley.

Oh ok, I get what he meant now.

I wonder why honda / acura settled on this gearing for this car then? Along with the check delay valve...I hope it wasn't to avoid any known weak points in the tranny? In effect this increases the stress on the FD right? But without the additional bolts that the other FDs have, as mentioned before, to distribute the additional stress.

Seems if honda used more appropriate gearing this would've been a mid-high 13s car?

To me, the additional ~400 RPMs in 6th gear on the highway is perfect, because then maybe I wouldn't have to downshift to 5th every time I need to speed up for a pass or something, like I do now. I don't mind losing 1-2mpg...this isn't my economy car.

 

Honda geared the car this way because it's seen as a "Family coupe," and not a performance coupe. It seems they wanted a sporty feel for the enthusiast, yet not so much that it would deter a 'normal driver.' This car easily could have been a high 13 car from the factory, all it needed was a gearing change.

 

Where is the list?

 

There is one on V6P in the Final Drive thread I believe. Could always make a new one here....I think there is one at the beginning of this thread too.

 

Found it

 

You've put how much money into this car? If you wanted to go faster, you could have just bought an LSx car and bolted on parts, and go even faster for less money. See how that logic fails both ways?

You're right though- I wouldn't spend $2000 on this. A gear set should really only be a few hundred bucks. Labor... Well, my time is "free." Sort of. I only pay for paint/body work, never acquired that skill set (more of an art).

No Civic wanted... Tesla is next.

 

Yeah but then he would have an LSx car

 

Finally got my ring gear back from being drilled. I had them install 4 plugs because those holes overlapped quite a bit.