How much more mph 1/8 to 1/4?

[turbojimmy]

Hi all,

What's a "normal" amount of MPH to pick up between the 1/8th and the 1/4? Last year I ran a 90.7 in the 1/8th and a 111.8 in the 1/4. Picked up 21.1 MPH. Some folks thought that was not enough given the 1/8th mile performance. Yesterday I went from 87.1 to 110.6 which is better, but I also had the car in 2nd by mistake so I'm not sure what the 1/8 MPH really would have been.

Just curious what other people are picking up 1/8 to 1/4 on a mid-high 11-second car (which mine should be if I ever figure out how to drive it).

Thanks,
Jim

 

[BobbyBuick]

I think 25 MPH is good untill you get real fast then closer to 30 mph..
Both my cars are right at 25mph when they are on a good Pass

 

[BlackBeauty]

I gained 21.8mph.
Did an 8.0@87.02, then finished with a 12.59@108.85. Only a 1.9 60'.

 

[XLR8]

My MPH goes up between 23 & 25 mph on a high 11 low 12 sec pass - from 90 - 114.

 

[JDSfastGN]

21-22 is pretty normal as long as the TC is unlocked, if you lock it you should gain 24-25 mph when running mid 11s. I typically gain 21-22 with a street chip, 21 psi and not locking the convertor. The run in my sig I saw 8* of knock and let out, i was hoping to see 116-117 as it was 115 with only 21 psi earlier that night

 

[turbojimmy]

Thanks for the info. On the older run I didn't have it locked (picked up 21 MPH). On this past Sunday's run the converter locked at around 75 MPH and I picked up 23 MPH. But, again, the car was stuck in second gear so I had lost a head of steam until I realized I needed to shift it into 3rd. Not sure ultimately how that affected the MPH.

I'll just have to do it again. Ideally I'd like to be in the high 100-teens. I'm going for *consistent* mid-11s. I think I have the hardware to do it, but I need more practice.

Thanks for the replies.

Jim

 

[UNGN]

The pick up in mph isn't really as important than if there is something limiting mph.

If 111 mph = 5200 RPM you aren't going to go much faster than this with stock heads and cam. Torque and HP fall off a cliff above 5K RPM.

If 120 mph = 5200 RPM (locked converter/28" tall tires) and you are only going 111 in the 1/4, you still have lots of RPM left.

 

[turbojimmy]

Originally posted by UNGN
The pick up in mph isn't really as important than if there is something limiting mph.

If 111 mph = 5200 RPM you aren't going to go much faster than this with stock heads and cam. Torque and HP fall off a cliff above 5K RPM.

If 120 mph = 5200 RPM (locked converter/28" tall tires) and you are only going 111 in the 1/4, you still have lots of RPM left.

That's what I'm trying to determine. I have 27" tires and a locked converter, P&P stock heads, port matched intake and a custom ground cam. I'm only running 100 octane fuel, though, with conservative (21-22 PSI) boost and timing.

I need to experiment more with this combo to see if there really is some kind of limiting factor (other than 2nd gear). First step is to remember to turn on DS so I can see what's going on at the end of the run.

Jim

 

[BobbyBuick]

I agree it is a great way to see if the car is perfoming correct in 3rd gear.A very good measure, I alway reference that as a target of 25MPH