It honestly looks beautiful! Its great seeing it can be done by those of us who work for a living. . .
Btw, what diameter is the exhaust outlet? Seems to suit perfectly

Hey Gentlemen, I was thinking of acquiring a 63A tranny as I bought my GX with an A15, and I'm uncertain if it was an auto or a manual originally. The tranny's out.
- Anyone know what the height and with dimentions are of the manual or the auto tunnels? I'd like to know how much space I need to make the 63 work.
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Many Thanks
Liebonhardus

Thanks for the ideas gentlemen. I mentioned the H165 to her as I did this for my GX with the A15, but her idea is to keep it GX. She's having new gears cut for her H145 and ordered shims. She'll be doing drags under 4 cyl N/A classes.

Thank You Sir.
We read nismo used to sell different centers for racing. Does anyone have experience with these?

Hi Guys,
Today I bother you on behalf of a friend who recently bought herself a beauty of a GX Coupe. This would be her second GX and this one's being built purely for drag racing. The car's drivetrain is entirely original from the engine down to the tires. Unfortunately the former owner did a lot of highway driving and the diff moans quite a bit at 130km/h. Now her A12GX engine and gearbox are being rebuilt for drags as I type this, but she's worried her diff won't hold up with her heavy foot. However, yesterday she spoke with a gentleman who said GX's were produce with 2 types of diffs:
1 -imported - diff center removes to the prop'shaft's side
2 - local - diff center removes through a rear backing plate

He also said she'd be better off rebuilding the original diff if it is an import, rather than buying another. We have mentioned to the man that the car would be driven abusively as its a drag car.

Any advice would be highly appreciated

I was aiming for the E16 Crank. Does her block permit a 15mm stroke increase? It's clear I have a lot to learn about this little A15.
Anyone know of a place I can read up on modifying A15's? So far I have her block on a stand ready for attention. All I've done is have her bored to 77mm and sand-blast the oil/water ports.

I've noticed fuel injection is not a common subject on this site. Is fuel injection not worth it? Should I rather just utilize her SU's?

Thanks Guys.
You gentlemen are really filling in the blanks for me.

I guess what my bore stroke question comes down to is: Do I bore her another 2mm to 79mm or do I stroke her to 88mm? Either increases the cc. Right now she's the underdog in her class (Circuit and KOTM), and class won't change 'til I cross the 1900cc mark. Mind you, how close can I get to having her bore/stroke square? I'd be satisfied if her cams are cut to limit her at 7500-8000rpm, as long as she has sufficient GRUNT (I grew up with RB30's and V8's, so chassis-twisting torque over HP for me, thanks).

The reason I ask about the diff and 'box is so that I won't have to buy others later. If the gearbox and diff can take the many different types of consistent punishment, then I'd be satisfied on buying extra CWP's and servicing the gearbox often.

Oh and yes, if her torque is sufficient (which it already is) I plan using a medium to light flywheel. Not too light though.

Thanks once again for the replies!

Thank You Sir!
I have read much of your input on many topic on this website, and I'm sold. I am curious about one or two of your answers though. Please don't think I doubt you! I'm simply curious and would like to learn from you!

You said increasing the bore would provide more torque than increasing the stroke. Now it was my understanding that a wider crank angle meant more leverage on the crank. This would sacrifice revolutions though. Where increasing the bore would leave you with a shorter crank rotation for the larger piston being forced down. This would in turn increase the revolution limit and also increase the revolution rate. So this being said, wouldn't it need more revolutions to enact the same amount of force on the crank, thereby raising the revolutions for peak torque?

Secondly, is there a possibility you might know how much punishment a "well-looked-after" B140 gearbox can take? I received 2 emails not to long ago confirming that the diff handled over 350nm in a circuit car, and 327nm in another everyday car for 57,000 miles so far with no hassles.

I am eager to read from you again =D

Hey Guys, been roaming the site and searching the web for this info, but unfortunately my decision will indefinitely depend on consensus. This post is the short and sweet version (5x shorter than the original), so forgive me for being blunt.

A15 in 1200 GX Coupe for daily highway driving, drags, drifts, and serious mountain sprints.
*I'm building her for torque* to suite all these conditions better.

She has a dry sump, the block's water and oil ports sandblasted, block bored to 77mm (during last service). Forged 'rods and pistons (Just in case I do eventually supercharge her), copper head gasket, coaxial valve springs, fuel injection, msd coil packs, and finally - before assembly, all moving parts will be weighed and balanced to be identical.

Now for the questions:
1 - I want to increase the stroke to 88mm rather than bore her out mainly because she's being built for torque and so that I can get a longer service life out of the block. Not to mention it should take quite a bit more punishment. This a solid idea?

2 - Knife edge the crank?

3 - If everything from the crank up is balanced, would a harmonic balancer still offer sufficient benefit?

4 - Considering local station's fuel is 93/95 octane and the motor has a longer stroke, what compression ratio should I be aiming for? I was thinking 10-10.5:1.

5 - I understand cams very basically, but I'm uncertain what I should opt for. I've been thinking of longer duration for the longer stroke, plus some duration for overlap (for pulse tuning).

6 - Is it worth enlarging the ports on the head? I understand more air+more fuel=more power, but this is still limited by valve size, and I'm also afraid of sacrificing torque.

7 - That sparks the next question - Correct exhaust diameter. Supercharging is my only form of forced induction if I do eventyally go that route, so branches and full free-flow are a must. Just not sure on the diameter (Also dependent on the former question) and 4-2-1 or 4-1? No cat's necessary in SA!

8 - ITB's or Single throttle manifold with MPFI? Both cases have an equally imbalanced affect on the crank.

9 - Fueling. I have no idea on the ideal air-fuel mix for this engine. Also, high pressure or high flow injectors?

10 - And lastly, would the B140's diff and gearbox handle this kind of hammering? Remember - Drags, Occasional Drifts, Serious Mountain Sprints, and Daily Highway time.

If you took the time to read through this, I'd like to express my gratitude and apologize at the same point. I could not have put these questions separately, or the bigger picture would have been missed. Many MANY thanks.

PS: I work for a living just like you gentlemen, but my living's for my GX!

No cutting. I still await my shortened axle. As for the body, I welded supports in between the "chassis", if you want to call it that, making it look somewhat like a ladder, and simply shifted the springs to attach to two of the cross beams.

The suspension is stiffer with the the retentioned leafs and smaller coil-overs up front. I've rolled out the guards a bit but I don't count on it to make too much of a difference. She's currently running on 175/70 R13x5 no scrubbing.

What do I need to do to get 13" x10"s in front?
What tire size would be appropriate?
How close can I get to the original overall wheel diameter?

Thank You Gentlemen
PS: I'd really appreciate any links to examples