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Max RPM For Street?

  • Thread starter Thread starter wickedmach1
  • Start date Start date Jul 9, 2004
W

wickedmach1

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Apr 8, 2003
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Austin, TX
Jul 9, 2004
#1
  • Jul 9, 2004
  • #1
What is normally the max RPM that you would run on the street if you had 3.89 gears and around a 26.5" rear tire? I am trying to build my 393 stroker engine and would like to know what RPM range is normally used. I want to size the engine correctly and not run out of my power band.
 
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wickedmach1

New Member
Apr 8, 2003
376
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0
Austin, TX
Jul 9, 2004
#2
  • Jul 9, 2004
  • #2
Yes, will be using either a G-Force T-5 or new Tremec tranny.
 

2bav8

Founding Member
Nov 30, 1998
2,511
1
47
Mesa, AZ
Jul 9, 2004
#3
  • Jul 9, 2004
  • #3
Do you have overdrive?
 

2bav8

Founding Member
Nov 30, 1998
2,511
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47
Mesa, AZ
Jul 9, 2004
#4
  • Jul 9, 2004
  • #4
I'd use 3.50 to 3.73s depending on how much rubber you can afford to replace.
 
U

usedtobe 67p51d

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Jul 8, 2003
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let's tear up golfcourses and build race tracks!
Jul 10, 2004
#5
  • Jul 10, 2004
  • #5
Is this a daily driver?
how much time will it be on the freeway?
is the car going to be heavy? ie:a/c,insulation,lot's of stereo,p/s,late model seats etc.


I look at all of the picture before choosing gears, If you live in area that the highway speed is 55-60 mph vs.75-80mph this all weighs into perspective.
if the car is light you can run 3:25's
if your not intrested in freeway cruisng you can run 3:89's

I built my 331 motor to come onto cam around 2500 rpm and at freeway speed it's right around 75mph. Most people will say that boging a motor will hurt the bottom end bearings as well as the rings so I decided that2500 would be a safe cruising rpm

a 393 motor doesn't need supper low gears to multiply torque like a 302 or 289.

if your useing a tranny that's not a overdrive you could run a 3:00 to 3:25 gear all day long with out issues I have a tremec with 4:11's first gear is way too low like 13 to 1! and final gear drops to 2.79 to 1 it's great on the highway I'ld love to have the new tremec 500 or 600 they have a tighter ratio would make it a easier trying to come up with the right ratio for the rear gear
 

blown65

Founding Member
Jul 7, 1999
1,938
4
39
Queen Creek Arizona
Jul 10, 2004
#6
  • Jul 10, 2004
  • #6
If hes running a T5 there is no need to put 3.25's in it. What is the OD gear in the Gforce? Multiply it out on the 3.89's and see what the actual final ratio is.
 
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wickedmach1

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Apr 8, 2003
376
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Austin, TX
Jul 10, 2004
#7
  • Jul 10, 2004
  • #7
The car will not be on the freeway that much and it will not be a daily driver, just weekend fun. It will most likely have newer model seats and floor board and door insulation. I hope the 3.89's are okay because they have been installed. I just need to pick my cam, intake, and heads. I know I need to decide the top end RPM I will be using and go from there. I want the best of both worlds, low end torque and I don't want to run out on the top end.
 
U

usedtobe 67p51d

New Member
Jul 8, 2003
208
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0
let's tear up golfcourses and build race tracks!
Jul 10, 2004
#8
  • Jul 10, 2004
  • #8
don't worry you'll have first gear traction issues

And more top end speed than you'll want{ my old motor only had 246 rwhp and I hit 142 with it only at 5200}
 
W

wickedmach1

New Member
Apr 8, 2003
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0
Austin, TX
Jul 10, 2004
#9
  • Jul 10, 2004
  • #9
What makes you think I will have first gear traction issues? Explain your statement, don't keep me wondering.
 
U

usedtobe 67p51d

New Member
Jul 8, 2003
208
0
0
let's tear up golfcourses and build race tracks!
Jul 10, 2004
#10
  • Jul 10, 2004
  • #10
traction issues...more torque than what the tires,springs and shocks can handle.

I only have 321#s of torque, a tremec, a 4:11 rear gears a torsen lsd, global west road race springs {they claim that you don't need "traction masters" with them and Michelins stickyest road rubber 245-45-16" pilot sports at 26-700 rpm I can drop the clutch.Anything higher is smoke. First/second shift at 6800 and it steps out a little ! second / third barks and fourth yelps going into fith is fine {never been at 6800 in 4/5 shift}
 
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