[joedls]

BTW. I'll be going to Pomona. Anything you want me to be on the lookout for?

[Vettezuki]

Originally Posted by joedls

BTW. I'll be going to Pomona. Anything you want me to be on the lookout for?

Don't knwo what all they have there, since I've never been, but:

- Repair Parts for the 174
- Holley 750 CFM Carb with four corner idle set (if on the pretty cheap side relative to new, might give that a whirl first)
- Radiator for an 2nd Gen RX-7, we don't have one
- Alternator w/Bracket
- Starter

These I can get new from Summit, but if you see them cheap:
- Scatter Shield for Top Loader
- Long Tube Swap Headers for SBF

I trust your judgement, send me the bill.

[Vettezuki]

Originally Posted by joedls

So how many tire revs per mile does your sheet calculate? Because I calculated the revs per mile using the exact circumference of what a 275-60-15 tire should be. I don't allow for any variances and frankly I don't know how your spreadsheet could do that accurately, considering different variances between tire, tranny, and rear-end manufacturers.

Here is my calculation.

(((275/25.4)*.6)*2)+15 = 27.992125 (Tire diameter)

27.992125 * 3.1416 = 87.940059 (Tire circumference in inches)

87.940059/12 = 7.3283382 (Tire circumference in feet)

5280/7.3283382 = 720.49076 (tire revolutions per mile)

Here's the Excel Fomula for Revs Per Mile I'm using:
=(63360/(((B9/25.4*(D9/100)*2)+F9)*3.141597)) *0.99

B9 = Section Width
D9 = Aspect Ratio
F9 = Rim Diamter

It's basically the same as yours, EXCEPT for the last multiplication. This actually reduces the number of revs per mile and therefore increase the speed for a given RPM. I believe it was the original desginers intention to account for growth in the tire as a function of heat/pressure and rotational inertia.

However, my sheet also inlucdes a big reduction when calculating the speed for a given tire/axle/gear @ RPM x.

=((D18/(B21*B28*H9))*60)*0.97

D18= RPM (shift or redline, or whatever you want to put in, I'm assuming 6k)
B21=Gear ratio
B28=Axle ratio
H9=tire revs per mile

The final multiplication is an additional reduction I forgot about. If I had to guess it's for nonlockup auto trans, but that's just a guess. Thanks for the catch.

I'll take out these constants for future calculations so we're comparing apples to apples.

[big2bird]

Originally Posted by Vettezuki

Don't knwo what all they have there, since I've never been, but:

- Repair Parts for the 174
- Holley 750 CFM Carb with four corner idle set (if on the pretty cheap side relative to new, might give that a whirl first)
- Radiator for an 2nd Gen RX-7, we don't have one
- Alternator w/Bracket
- Starter

These I can get new from Summit, but if you see them cheap:
- Scatter Shield for Top Loader
- Long Tube Swap Headers for SBF

I trust your judgement, send me the bill.

Alt and starter you can get cheap from the zone rebuilt, and forfeit the $10 core charge.
Radiator, I would hold off on. I may get that REAL cheap from a friend. (He owns Anaheim Radiator). He can probably make us one custom.

[big2bird]

Originally Posted by Vettezuki

Here's the Excel Fomula for Revs Per Mile I'm using:
=(63360/(((B9/25.4*(D9/100)*2)+F9)*3.141597)) *0.99

B9 = Section Width
D9 = Aspect Ratio
F9 = Rim Diamter

It's basically the same as yours, EXCEPT for the last multiplication. This actually reduces the number of revs per mile and therefore increase the speed for a given RPM. I believe it was the original desginers intention to account for growth in the tire as a function of heat/pressure and rotational inertia.

However, my sheet also inlucdes a big reduction when calculating the speed for a given tire/axle/gear @ RPM x.

=((D18/(B21*B28*H9))*60)*0.97

D18= RPM (shift or redline, or whatever you want to put in, I'm assuming 6k)
B21=Gear ratio
B28=Axle ratio
H9=tire revs per mile

The final multiplication is an additional reduction I forgot about. If I had to guess it's for nonlockup auto trans, but that's just a guess. Thanks for the catch.

I'll take out these constants for future calculations so we're comparing apples to apples.

Quit bench racing. So your off 1mph or so. The traps will tell the truith.

[joedls]

Originally Posted by Vettezuki

Don't knwo what all they have there, since I've never been, but:

- Repair Parts for the 174
- Holley 750 CFM Carb with four corner idle set (if on the pretty cheap side relative to new, might give that a whirl first)
- Radiator for an 2nd Gen RX-7, we don't have one
- Alternator w/Bracket
- Starter

These I can get new from Summit, but if you see them cheap:
- Scatter Shield for Top Loader
- Long Tube Swap Headers for SBF

I trust your judgement, send me the bill.

I'll call you if I stumble upon a good deal. Is someone maufacturing headers for this swap?

[Vettezuki]

Originally Posted by big2bird

Quit bench racing. So your off 1mph or so. The traps will tell the truith.

We don't have a car to race for real yet. And this is (theoretically) for choosing the best possible total combo in the first place.

[Vettezuki]

Originally Posted by joedls

I'll call you if I stumble upon a good deal. Is someone maufacturing headers for this swap?

These appear to be the best candidates for our swap.

[Vettezuki]

Originally Posted by big2bird

Alt and starter you can get cheap from the zone rebuilt, and forfeit the $10 core charge.
Radiator, I would hold off on. I may get that REAL cheap from a friend. (He owns Anaheim Radiator). He can probably make us one custom.

Roger. I've been using Duralast alts and starters on other vehicles for a while, and they seem pretty well made and reasonably priced. BTW, what years was this motor in production, or what car can I use as the reference when buying parts?

[big2bird]

Originally Posted by Vettezuki

These appear to be the best candidates for our swap.

I have been meaning to ask. What is the latest NHRA on sound? Are open headers still okay? (Dating myself)