1972 Float Adjustment ...

[240260280]

Maybe your Z has a differential from an automatic?  If you install a differential with 3.7 to 4.1 ratio, your 1st gear will pull better.

[240260280]

Also, if you think your car is running lean on acceleration, try putting an 80wt oil (thick) in the carb dampers to see how enriching the transition works. 

If you think your car is running rich on acceleration, try putting ATF (thin) in the carb dampers.

30wt oil is the recommended oil for your climate.

Edited July 17, 2018 by 240260280

[jalexquijano]

I already have atf in both of my carb dampers

[jalexquijano]

56 minutes ago, 240260280 said:

Maybe your Z has a differential from an automatic?  If you install a differential with 3.7 to 4.1 ratio, your 1st gear will pull better.

My car has a 280z 5 speed tranny installed

[jalexquijano]

The car differential is stock from a 240z. 

[Patcon]

It is probably a gearing issue overall. Depending on which 5 speed you have, your gearing could be a little high, which will make your launch a little slower. If you go to a lower gearing in the rear end then your cruising rpm's at 100mph is going to be much higher. There's no free lunch here. After all, you are only working with 150 or so HP if you're lucky. It's not going to launch like a modern EFI car that makes 200 or more HP and could have as many a 8 tranny gears. For us in the states, law enforcement tends to lower the speed range we build for, so we don't have to worry so much about higher rpm's. We can run lower rear end gearing and not have to worry about high speed rpm so much

[w3wilkes]

2 hours ago, Patcon said:

For us in the states, law enforcement tends to lower the speed range we build for, so we don't have to worry so much about higher rpm's.

What does this mean? Out here in the western states we have hundreds of miles of interstate with 80 MPH speed limits.

[Mark Maras]

IMO the slow response in first gear is the nature of the beast and is likely made a bit worse with the upgraded camshaft. I'm assuming that around 3000 RPMs it starts pulling strong. A lighter flywheel could help it a bit in the lower RPMs but a heavier flywheel is better for stop and go traffic.

[Patcon]

7 hours ago, w3wilkes said:

What does this mean? Out here in the western states we have hundreds of miles of interstate with 80 MPH speed limits.

This is true, and in some places like Montana they have effectively no speed limit. However, if you look at the member map, most of the member cars reside in areas that have substantially lower speed limits. Jalex  (who is in Central America) is evidently routinely running a 100 mph in his car evidently for extended periods of time. I suspect if 100 is the norm, then 120 is not out of the question. I don't know about Utah but much above 80mph where I live is going to get you tagged (our highest speed limit is 70 mph). Even in Texas they have very high speed limits (80 mph on secondary roads) but many times they will ticket you for 5 mph over (got one about 2 years ago), where as they tend to give 10 mph here. Big difference in rpm from 85 mph to 120 mph...

Another point is many people set their cars up for acceleration, light to light so to speak. Most are not set up for high speed cruising. That being said I have run a z for hours above 5k rpms with a four speed with no obvious ill effects

[gundee]

The reported 100 psi across compression test, if correct, would also result in that performance. Just reminding.

[Mark Maras]

 I don't remember compression readings that low. Probably just me. @jalexquijano What were the compression readings the last time they were taken?

[gundee]

2 hours ago, Mark Maras said:

 I don't remember compression readings that low. Probably just me. @jalexquijano What were the compression readings the last time they were taken?

Mark, see your post #623