frankinstine

[92wip4dr]

ok but when u shift at a lower rpm u start next gear at a lower rpm so its like when u drag it all the way out u start next gear that much higher you know what im saying?

[cloudasc]

ok but when u shift at a lower rpm u start next gear at a lower rpm so its like when u drag it all the way out u start next gear that much higher you know what im saying?

I understand that, but do you understand the stock motor/camshaft doesn't give you any more power reving that high, its causing excessive wear on everything.

Take it to the track, and do a couple 1/4 or even 1/2 mile passes, shifting at the factory redline, vs shifting your way. Let the slips speak for themselves.

If the engine made good power at those revs, and could handle them safely, don't you think Honda would have done so?

The gears are long for the f22a transmission, to get the desired effect your looking for, you would want to swap in an h22 or h23 transmission instead, but you should still not be reving your motor that high, unless you have the supporting modifications.

[SOHC-FTW]

The right shift points are hardly ever at redline anyways you can rev something all day, but doesn't mean it makes power throughout the band eventually it starts to drop off. That is usually a few 100 rpm's or more before red line, and every gear will be different, it really helps to have a tq&hp graph (Dyno is best) from your setup to see where it peaks at both tq&hp.

[cloudasc]

The right shift points are hardly ever at redline anyways you can rev something all day, but doesn't mean it makes power throughout the band eventually it starts to drop off. That is usually a few 100 rpm's or more before red line, and every gear will be different, it really helps to have a tq&hp graph (Dyno is best) from your setup to see where it peaks at both tq&hp.

Totally true, but even if the op were to shift at redline, it would be better then revving it to where they are now.

I have a dyno sheet for my car, its my equivalent "baseline" (Ignore the spike at the end, from the auto tranny shift):



110whp/108wtq

This run was done in 100*F heat, in an automatic. Video proof is in my MRT.

If my car was converted to a manual, I would be putting down an additional 18-20 whp/wtq.

I have the original airbox and a1 exhaust still, on an a6 setup. P&P Flowbalanced a6 runners, "double-stack", with h23 plenum & tb, and a bisi heat shielding intake gasket. I also have an unorthodox racing stock diameter lightweight crank pulley, and one accessory pulley.

I can feel, and can be seen in the dyno, once I get to 5.6-5.8k with my setup, the stock a1 exhaust becomes a bottleneck, as the hp just flatlines.

SOHC-FTW, out of curiousity looking at the dyno chart above, where would you shift?

[deevergote]

The automatic doesn't provide 18-20% loss OVER the manual... you might see another 5whp with a manual swap, tops.


92wip4dr, you need to learn a bit about your engine's powerband.

[cloudasc]

The automatic doesn't provide 18-20% loss OVER the manual... you might see another 5whp with a manual swap, tops.

The numbers I used were based off another member on here's before and after auto to manual swap dyno results, where the only thing they changed was the transmission. Which member it was I cannot remember, as I did the calculation over 2 years ago. I am not just picking numbers out of my ass either. The difference in power between the two at the time was close 15%. 110 (my power now) / 129 (estimated power with manual) = .8527.

Although that difference could be caused by several factors, like a not in good health automatic converted to good condition manual.

The automatics today are far more efficient then the automatics we have in our cb's.

[deevergote]

Our manual transmissions are estimated to give roughly 18% drivetrain loss... meaning a 125hp F22A1 would put down about 102whp. So for there to be an additional 18-20% loss with an automatic transmission... that's a drivetrain loss of about 45hp. That's pretty extreme, if you ask me.

[cloudasc]

Our manual transmissions are estimated to give roughly 18% drivetrain loss... meaning a 125hp F22A1 would put down about 102whp. So for there to be an additional 18-20% loss with an automatic transmission... that's a drivetrain loss of about 45hp. That's pretty extreme, if you ask me.

That sounds more like the drivetrain loss for a rwd manual. Remember FWD manuals are much much simpler, they don't have to spin a driveshaft, and a rear differential. 5-8% drivetrain loss is what i'd expect out of a fwd manual. FWD Automatics have a 15-20% approximate drivetrain loss.

I've posted a dyno sheet of my setup, all mods are documented. I should be putting out over 140hp at the crank, but I only get 110hp to the wheels. Thats a 22% difference. How much hp are the accessories like the alternator, power steering, and a/c pulley accountable for?

[deevergote]

20-22% is what I'd expect from an automatic, honestly.
The accessories aren't really accountable for very much, really. 1-2% tops, I'd assume. Is your baseline 100% stock? No intake, exhaust, etc?

Even though there's no driveshaft running the length of the car, we still have all that complex gearing in our transmissions, and it's still transferred through the driveshafts. I don't think there's all that much difference between FWD and RWD. AWD is another story... drivetrain losses are greater there.

[cloudasc]

Yes thats my baseline, its pretty much stock, originally an a1.

Bisi intake gasket, p&p gasketmatch/flowbalanced a6 runners, gutted iab, functional iab, h23 plenum & tb, stock airbox (k&n panel), stock a1 complete exhaust, a6 cam, bisimoto pro springs, pt6 ecu, unorthodox stock diameter crank pulley, unorthodox power steering pulley. Not that it matters, but I also added the a6 oil cooler, and the windage tray to my a1, so it truly is a "a6".

Compression results were 185/180/185/185 for this motor when tested.

[deevergote]

The windage tray matters (a very small amount, anyway) at higher RPM.

[SOHC-FTW]

From the calculator i use from time to time because i'm no expert on such (and i really can't see all the numbers) 6100-6200 rpm's in 3rd would keep you around 4700 once into 4th as for 1st-2nd staying in peak tq helps abit more on acceleration around 6500 in those two would put you around peak tq.

Like i said i'm no expert on the subject i know the basics/concept. But your probably not as stock as you were so this means nothing. Oh and i hope to put down close to 125whp give or take on my slush box before the cam&nitrous.

[8ball]

disregard deeve aquire blown engine.

[8ball]

my auto in second gear around 30mph to about 60 was quick like super quick. I had a p12 with a cd5 tcu.