Honda Civic 92-95 advice : add-ons

[downingracing]

Tom B. has a reputation for building VERY good motors. I know he knows what he is talking about. I'm guessing the 4.5 FD comment was meant as the all around best choice for running a single gearbox. I love my 4.9, but have been places where I'd rather have the 4.7 or even my OEM 4.25?... Multiple boxes would be the way to go, but this is club racing and having the 'best' choice for the tracks you run is more like what people have. I run mostly at Mid-Ohio and have found the 4.9 keeps me in 3-4-5 and I'm shifting 1/2 as many times a lap as running the stock FD.

Thanks!

Matt

[Tom Blaney]

Thanks Matt, your exactly right. Most club racers don't have a huge budget, and have to build a car for the area they race. The first CRX I had came with a 4.9, and for the tracks I ran it seemed too tight, and I would be shifting at inappropriate points on the track. I went to a 4.7 which was better but still was tight in 2 at L/R and or out of the boot at the Glen. The stock 4.2 was actually very very good at Pocono, but that was about all. When I got hooked up with the 4.5 from Gear-X it seemed to work better than the others.
Also as you indicted a lot has to do with skill, driving style, and car setup, so if you want to go as fast as you can you have to experiment not only with gears, but with wild swings of suspension settings until you find what works for you.

[jimmyc]

Tom B. has a reputation for building VERY good motors. I know he knows what he is talking about. I'm guessing the 4.5 FD comment was meant as the all around best choice for running a single gearbox. I love my 4.9, but have been places where I'd rather have the 4.7 or even my OEM 4.25?... Multiple boxes would be the way to go, but this is club racing and having the 'best' choice for the tracks you run is more like what people have. I run mostly at Mid-Ohio and have found the 4.9 keeps me in 3-4-5 and I'm shifting 1/2 as many times a lap as running the stock FD.

Thanks!

Matt

While that could very well be true, it looks like all of his experience is on a D16a6

Which is a COMPLETELY different motor then the D16z6

And then he throws out a 7800rpm limit that i didn't see any one talking about, nor is that what it is set at on the trans graph.

[mossaidis]

okay... back to our old thread to discuss FD. Readin this site is sometime like listening to my parents. I love you, but so much drama.

First, my tranny consists of ONLY OEM synchros, bearings and seals. I replace the shock bushings as well - most don't. The LSD is a new Quaffie (I have a deep affection for that part... uh). I use 2 parts Redline MTL and one part Redline Lightweight Shockproof every 4 track days. The oil combo seems to work fine though I have not opened the tranny in 20 track days. The clucth is an ACT 6 puck spring disc with a heavy duty clutch plate. Motul 600RBF in the clutch line which is either now solid or braided.

Second, the car has NOT been dyno'ed since I got the head shaved, port matched and installed the "tunnel dump 97 db @ 50ft" exhuast. Before these mods, the motor peaked hp at 6800 rpm - just like stock - and VTEC engagement changed from 4800 to 5100 rpm. Then why the 7800 redline? Well, mainly due to the big gap left between 2nd and 3rd gear. 1st and 2nd gear were designed to "thrust" the little civic from 0-to-60 as fast as possible. 3-5th were designed for med speed pull and high mpg. So a redline 7200 shift from 2nd to 3rd places the engine below Vtec and acceleration is sluggish until its revs to 5.5K. Push the redline to 7800 and gear shift from 2nd to 3rd places the engine at over VTEC engagement. So even though I am losing HP at the top of 2nd gear, my 3rd gear engine rev placement is soo much sweeter. FYI, before the IT mods, my shift point for all other gears was 7200.

Even when I removed the CAI to install the short AEM intake, the car pulls so much nicer after the IT mods - duh right? If I were to guess, I think peak HP is around 7200 rpm. I won't know for sure until after my next tune - probably in the spring 2010. So, my gut tells me to shift at 7200-7300 rpm except for when in 2nd.

Tires: unless GY releases tires before 5/30 (doubtful) I will run SM6's for the 5/30 LRP, 6/20 LRP and 7/25-26 WGI events. At 22.8" diameter, comparing 4.25, 4.7 and 4.9 FD at 7200 shift rpm, speeds go as follows:

4.25FD 4.7FD 4.5FD

35.37 31.99 30.68
60.5 54.71 52.48
91.97 83.16 79.77
126.47 114.36 109.69
153.28 138.6 132.94

Wow, it's I have a 5th gear now! I think a 4.9FD is the way to go.

[Ed Funk]

after seeing you run at NHMS in apr, I think you need a 3/4 inch SIR

[mossaidis]

(Deleted for being a jerk) you going to LRP on 5/30? When do I get to meet the wifey?