?'s re: 1/4 mile RPM's & MPH w/ 4.10's & AOD

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 7, 2005

#1

• May 7, 2005

• #1

Hey guys,
I went to the track for the first time last night.
I ran my street tires all night, got horrible 60' times (2.7- 2.378), and got my first run of 17.12 down to a 14.58
My top MPH was 96.21.

So here's my question: My AOD mods are in my sig. At the top of the track, my RPM's were at 6 grand. Isn't that high?
I kept it in D and it never shifted into OD , but all my runs were between 95-96 MPH (except for that 17.12 :damnit: ), and all tahced to 6000.

So, is something amiss? Do I need to adjust the TV cable down a bit? I have messed w/ it in the past.
Is it because of my tires (also in sig) they're only about 1/4 - 1/2" taller than stock 15" tires and wheels, and they were at 20 PSI.
Next week I'm planning on running w/ M/T ET streets.
Given that my 60's should impove considerably, what will that do to my top end MPH and RPM's?
With a stock motor, I wouldn't think that my car is making power at 6 grand, especially w/ a stock fuel cutoff at 6250, if I'm not mistaken.
Can anybody given me any info as to how I can lower my trap RPM's or if this is normal and the car's still making power???

Thanks,
Jeremy

 

G

grrrrrrr

New Member

May 20, 2003

289

0

0

norfolk, VA

May 7, 2005

#2

• May 7, 2005

• #2

I don't know much about vert's but assuming your higher weight I'd say you're about average...

 

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 7, 2005

#3

• May 7, 2005

• #3

I'd have to get it weighed, but I think my McLaren is lighter than a regular vert, cuz there's no backseat or hydraulics or extra equipment for the convertible top....

But if it was average, then how can I lower my RPM's at the top while building speed at the same time?

 

G

grrrrrrr

New Member

May 20, 2003

289

0

0

norfolk, VA

May 7, 2005

#4

• May 7, 2005

• #4

I don't think I know enough about auto's to really help you out. The only things I can think of to reduce your rpm's at the big end of the track would be to get numerically smaller gears or larger diameter tires. Those would be cheapest. After that I think you have to change the cogs in the trans... What size tires are you running? What about your rim size? Maybe your tach is off? I hear it's not common for the factory tach to be off by 500 rpm or more. Someone here who knows the cog sizes of the trans and with your tire outside diameter can compute the RPM you should be theoretically running @ at 96mph... Hopefully that someone will chime in here shortly. Now, about your times. I'm going to assume you cut the 2.378 60' on your 14.58 1/4. Get those 60's down to 2.xx and you'll see low 14's... Good luck...

 

notchback

Founding Member

May 30, 2000

1,950

0

36

St Clair Shores MI

May 7, 2005

#5

• May 7, 2005

• #5

your fine w/ the 4.10's...it's trapping high r's from you spinning so bad off the line, then the r's just keep climbing.

w/ traction...you won't be near 6 grand til your running mid 12's

thats where my stock notch 5-speed was in 4th w/ 4.10's running 12.50's on the juice....5800 rpm going through the lights.

also, your going by the stock tach i assume? probably way off.

there's no way your tach'ing that for real, and if your tires are taller than stock...that reduces gear and r's as well

btw...w/ your slippity-do-dah-day 60' times...looks like your capapble hitting 13's w/ traction

post those when you get 'em

 

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 7, 2005

#6

• May 7, 2005

• #6

notchback said:

w/ your slippity-do-dah-day 60' times.

Click to expand...

that's awesome...good saying!!!
But seriously, though, those 60's killed me!
I'm hoping that weather cooperates next Wed. and I can use the ET Streets to cut some good times before my buddy gets his engine in and I'll have to buy some of my own.
With 2' lowering springs, what will be the tallest drag slick (DOT) and wheel combo that I can fit and would benefit my times?

 

RYC CUKR

Founding Member

May 19, 2002

1,437

1

38

Orlando

May 7, 2005

#7

• May 7, 2005

• #7

I went 14.457@97 last time I went to the track. You can look at my sig and see what I have done to the car. The only thing that is there that I didn't have then was the P heads.

Spun pretty good leaving the start line. Not sure what the stock tach was reading when I crossed, I don't trust it so I don't really pay all that much attention to it. I need a converter and traction pretty bad right now. So since I have to rebuild the old AOD I figure I will wait on the converter until I have the trans pulled for that.

 

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 7, 2005

#8

• May 7, 2005

• #8

how do you like the addition of the P heads? Are they worked?

 

ramjetlx

New Member

Apr 8, 2005

212

0

0

Honolulu, Hawaii

May 7, 2005

#9

• May 7, 2005

• #9

Its all in the launch!!! Gently ease into it and then punch it once you feel it hook.... You just have to expirement with your launch....

 

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 7, 2005

#10

• May 7, 2005

• #10

Yeah, I def. have to learn how to launch. At times, I got it to hook, then punched it, then lost it again. I think alot of it depends on the condition of the track and what time of the night it is, as traction got worse at the end of the night....

 

RYC CUKR

Founding Member

May 19, 2002

1,437

1

38

Orlando

May 7, 2005

#11

• May 7, 2005

• #11

So far so good with the p heads. I dynoed it before I put the p heads on and with my mods up to then it was around 240-245 hp and 300ft-lbs. Haven't gotten it dynoed since then. Before the heads if you stood on it in 2nd it would down shift and you would get a little chirp now it almost gets sideways so there is a difference. If I get it dynoed in the near future I will post my #s

 

jaymac

New Member

Feb 18, 2004

995

0

0

Northern Mass

May 8, 2005

#12

• May 8, 2005

• #12

yeah, be sure to let me know, PM me or post back in this thread!
Thanks,
J

 

trevnut

Member

Dec 21, 2003

67

0

6

Mustang,OK

May 8, 2005

#13

• May 8, 2005

• #13

i run 12.90's at 106 with 4.10's and a aod with 26 inch tires and im at 6000ish