Tuning the JDM B20a (Gold Top)

[Versanick]

So here I find myself, years after getting this car, and fixing it up how I want

Gude head package (race cams, race head p&p, valve job, etc)
BLOX intake manifold
DC Header + Full exhaust
hyper-eutectic pistons w/13:1 comp
AEM Adj cam gears
OBD1 converted (just took EVERYTHING from a 93 integra and plugged it in, was easy with the BLOX manifold already there, removed vacuum box).

Anyone in these shoes, what are you using as a base tune?

We're trying to use a stock Acura Integra LS tune with the rev limit set to 8200 and the idle turned up to 800 (to keep it idling). Going to tune from there. Have chip burner. Going to use Uberdata.

Car ran great last year straight through 8000 with this setup, no tuning, cam gears at 0 degrees.

Track tuning on Saturday. Will Report.

[2ndGenGuy]

Track tuning? VIDS!!! Sounds like an exciting build, are you going to dyno it when you're done?

[carotman]

Don't rev it to 8000, bring it down to 7500 if you want a longer lasting engine. The B20A Rod/stroke ratio isn't suited for 8000 rpm.

[bullard123]

What's been up man!!? Haven't seen you on in a while. Glad your still doing great things to the hatch. I will definately stay tuned to this thread. Sounds like you have a nice setup going there

[RobT5580]

I was wondering what happened to you! I plan to run hondata this time around. When i had the AEM EMS they used a teg basemap and tuned from there but it was all custom and the base was just a starting point.

Definitely get that tuned properly and yeah i agree with carotman i would not rev it that high.

[MessyHonda]

sweet...another b20 build....post some pics

[88LXi68]

are you going to Lebanon Valley?

[Versanick]

OK, so after the car broke a few more times, we finally got it to the track 8/6/2010.

Times in the 60 ft started at 2.6+ with way too much air in the tires

and wound up down at 2.15 with 20psi in each front tire

Times in the 1/8 started as high as 10.6, and one run with 20psi in the tires, I dipped into the 9's with 9.94.

After about 10 passes, the clutch started pouring smoke EVERYWHERE around and in the car. Wasted it.

So now I'm looking for another clutch for my b2k5 tranny. After taking it apart, the clutch plate literally broke in half with all of the abuse. I think the 88-89 prelude Si b20a5 one works, so I'm gonna grab one of those. Right now we put in my friend's 88 civic si b16a cable tranny's stage 2 clutch plate, and when you let the clutch out all of the way, you can go PART throttle, but if you open it up, the clutch just slips all over.

I'll upload some pics here this evening, since I don't have any up. I have some crappy cell phone vids, but all of the good vids are on my buddy's gf's digital camera.

BTW: Power doesn't even START until 5500rpm.

First gear I take to about 8500rpm
Second gear to just under 8000
and third gear finishes the race.

I was making sure that, when I shift, I'm right in the 5500rpm range, feels like ~170 ft/lb of torque, which dies fast after 7500rpm, but in first gear, it keeps the car moving better than second.

[bullard123]

Wow those are some really good numbers! Yes the B20A5 clutch works, thats what Im runing in mine. Aint the best clutch though if its OEM than yes....got mine from autozone. You've dynoed it before right?

[Versanick]

Wow those are some really good numbers! Yes the B20A5 clutch works, thats what Im runing in mine. Aint the best clutch though if its OEM than yes....got mine from autozone. You've dynoed it before right?

Absolutely not. These numbers are roughly based on the fact that the car is >2400lb, compared with known dyno numbers for cars it's running against that are ~2000lb, as well as the aDyno app on my android phone, and how it 'feels'.

No n/a honda I've ever ridden in, in my entire life, has pulled as hard as my car does from 5500-6000rpm. That's no exaggeration.

Al's 89 civic with jdm b20a with bolt ons like crazy, chip, and light flywheel makes ~180hp, and pulls similarly hard, including to a higher rpm (but the car is 500lb lighter).

I'm estimating that my flywheel hp isn't more than 200, but it's really hard to tell. We haven't advanced/retarded any cam gear timings (both just sitting at 0 degrees), so there is probably some power to be shifted there, but air/fuel is DAMN close.


100MEDIA95IMAG0026 by pkopalek, on Flickr

That's my clutch. We welded the front differential, BTW, for better launches and traction.

I've never heard of, on any message board, or through word of mouth, ANYONE ever welding the differential except for me. Let me tell YOU, very very very difficult to drive around turns and so on, but VERY HARD launches. My launches, after a few practice runs, were keeping right up with RWD cars with slicks through 60 foot times.

This is an awful video of my buddy Dusty racing my car that same night (even though he didn't sign up, he looks like me so they didn't notice. He got smoked by a 500 ft/lb diesel truck with 4wd. Embarassing, and a very grainy video. But when I get better ones around, I'll see if I can upload them.

http://www.youtube.com/watch?v=f7YwtQB7t-8

[Versanick]

And I'm not really 100% sure about this b20a5 clutch thing. I feel like I got one last time, and something didn't fit right. I'm pretty sure that we used a pressure plate from an 86-89 a20 accord, and whatever clutch disc fit properly.

Remember, this is the GOLD top b20a, which has the b2k5 transmission, not the f2k5 transmission (black top) b20a.

Feel confident on the b20a5 clutch? I might get a 6 puck

[mykwikcoupe]

I answered this question in my post just above this one. When Josh built that car he went relly in depth into it. Im sure the bumped CR helps as well. Hopefully you kept it in good shape. Id watch the upper level prelude kits. Ive got the highest holding pressure plate ACT makes and Im waiting for it to snap the cable. Its supper tight to move. Otherwise its great, engages smooth and feels nice just very tough to operate daily

[Versanick]

I answered this question in my post just above this one. When Josh built that car he went relly in depth into it. Im sure the bumped CR helps as well. Hopefully you kept it in good shape. Id watch the upper level prelude kits. Ive got the highest holding pressure plate ACT makes and Im waiting for it to snap the cable. Its supper tight to move. Otherwise its great, engages smooth and feels nice just very tough to operate daily

I saw that you answered it, as I've also read everywhere else.

BUT, that wasn't my experience the first time I got an 88-89 b20a5 clutch:


https://www.3geez.com/forum/showpost....7&postcount=28

Again, I'm using the stock flywheel, not the b20a5 flywheel. I don't know if what I experienced before was a fluke, or if it was because of this. It really looks like a b20a5 disc with an a20 plate will fit...

[mykwikcoupe]

thats fine, Good luck. I was just letting you know that despite the issues others had with the b20a5 flywheel mine is working well aside from the rubs in the trans case.

[bullard123]

Mine has been working fine too...I think I used the B20A5 flywheel as well. I know it doesnt rub the tranfer case. But yeah I have the B20A a blacktop from a 88 Accord just like mine ...Carotman can give you the right answer, shoot him a pm. I know I was pm'ing him daily when I was trying to get mine running. Have the aftermarket cam gears given you much noticeable power? I have goldtop cam gears in my blacktop and they feel pretty good but I will be willing to switch them if it makes a big difference

[Versanick]

Again, I'm not using the b20a5 flywheel. I'm using the b20a flywheel.

So the b20a5 clutch plate works, but the a20 pressure plate is necessary.

The b20a5 pressure plate is like 21-spline, and way smaller. The shaft going into the tranny is WAY bigger than that, and needs what looks like 24-spline. The a20 is the only fit.

So we've ordered a stage 4 6-puck disc for a b20a5, and a stage 2 pressure plate for an a20. I'll try to get pictures hosted, but it'll depend if greasy hands are willing to grab a phone/digital camera.

Going to use the old throwout bearing, it looks fine.

[carotman]

I think there are 2 different B20A flywheels. One with an A20A pressure plate style and one with a B20A5 pressure plate.

[RobT5580]

Maybe the flywheel makes a difference i ran the Fidanza B20A5 unit with a B20A5 Clutch Masters puck clutch which did work fine.