bossman032

I have a ctr motor in a 99si.

I am going 60 mph and the rpms at 4000 is this normal?

also I am running 16" rotors with low profile tires. But I am just making sure this is normal...

Probot

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bossman032 &raquo;</TD></TR><TR><TD CLASS="quote">I have a ctr motor in a 99si.

I am going 60 mph and the rpms at 4000 is this normal?

also I am running 16" rotors with low profile tires. But I am just making sure this is normal...</TD></TR></TABLE>

couple things mon frere - what gear are you in when you are at 6000rpm?? 5th?? and secondly...how did you manage to get tires on your brake rotors???

crazyguy

if u are on 5th gear then wow. it is really short. on my jdm b16a sir2 tranny.
i cruise on highway at 5th gear at 73 mph @ 4000 rpm

Probot

and running 16s wont make your speed change that much...or at all for that matter..maybe .5mph...would give you more top end than anything...smaller rims would make your car accelerate faster and lose top end

thisisntjared

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Probot &raquo;</TD></TR><TR><TD CLASS="quote">how did you manage to get tires on your brake rotors???</TD></TR></TABLE>wait wait. so you dont put your tires on your brakes?

Padawan

First, are you asking about indicated or actual speed?

b16a3delsol

gears seem really short but i think we all know that.

Malakai

Gotta love those short geared trannys!

IanB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Probot &raquo;</TD></TR><TR><TD CLASS="quote">and running 16s wont make your speed change that much...or at all for that matter..maybe .5mph...would give you more top end than anything...smaller rims would make your car accelerate faster and lose top end</TD></TR></TABLE>

That has everything to do with the size of tires mounted on the rims, it could throw it out higher or lower depending on that.

B16 tranny's are very short geared, what you are experiencing might not be what you expected, but it's normal. Swap in an LS 5th gear for the highway, and put in an LSD while you have it apart.

Malakai

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IanB &raquo;</TD></TR><TR><TD CLASS="quote">

That has everything to do with the size of tires mounted on the rims, it could throw it out higher or lower depending on that.</TD></TR></TABLE>

Don't think so bub. Even tho the wheel increases in diameter, the tire size decreases. Thus equaling each other out. There was a guy on here that had a whole formula for this. In essense a 14" wheel and tire, is almost equal in size to a 16" wheel and tire.

Your speedo would be off by like 0.2 +/- a few 0.X mph or something. If anything weight will be the contributing factor.

IanB

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Malakai &raquo;</TD></TR><TR><TD CLASS="quote">

Don't think so bub. Even tho the wheel increases in diameter, the tire size decreases. Thus equaling each other out. There was a guy on here that had a whole formula for this. In essense a 14" wheel and tire, is almost equal in size to a 16" wheel and tire.

Your speedo would be off by like 0.2 +/- a few 0.X mph or something. If anything weight will be the contributing factor. </TD></TR></TABLE>

That's if you don things the right way, lol. The guy that I quoted was talking like changing wheel size means your car will have more top end or more low end acceleration, simply not true. I fully agree with what you are saying.

"would give you more top end than anything...smaller rims would make your car accelerate faster and lose top end"

B serious

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bossman032 &raquo;</TD></TR><TR><TD CLASS="quote">I have a ctr motor in a 99si.

I am going 60 mph and the rpms at 4000 is this normal?

also I am running 16" rotors with low profile tires. But I am just making sure this is normal...</TD></TR></TABLE>

No. It's not normal. You should be around 3300ish at 60mph. At 4k you should be almost right at 70mph square on.

Maybe your cluster is off. Either your tach or your speedo.


Or maybe someone put a crazy Final drive in your trans before you got it.
What size tires are you using on your 16'' wheels?

ERIC1

yep that is not normal
at 70mph u should be exactly at 3900rpm
dude i think u made this up!

slambedcivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Malakai &raquo;</TD></TR><TR><TD CLASS="quote">

Don't think so bub. Even tho the wheel increases in diameter, the tire size decreases. Thus equaling each other out. There was a guy on here that had a whole formula for this. In essense a 14" wheel and tire, is almost equal in size to a 16" wheel and tire.

Your speedo would be off by like 0.2 +/- a few 0.X mph or something. If anything weight will be the contributing factor. </TD></TR></TABLE>

youre comparing apples to oranges.... you mean to tell me that a 15" wheel with a 195/60 tire is going to yield the same rpm-mph as a 195/50?

slambedcivic

to the OP. your rpm seems a lil high for your speed. maybe your speedo is a lil off.

bossman032

word.

something is wrong then.. cluster is fine well at least I know. it might be the rpms are off or something. he is running some 16" rims and low profile tires.
I have no clue its my friends car its a 99si that came with a stock b16. Then we swapped it over to b16b which was my motor sitting in his garage.
I am not sure whats wrong. but I was driving the car and I noticed that 60@4000 rpm. I can take a video of it but wtf.. it is what it is..

Dan8yourV8

yeaH and got to love them high R's

bossman032

ok I looked at it again.

its about 3800. not actually 4000rpm.



hopefully this makes sense..

VRD^sam

i hate driving at 4k on the highway it gets annoying

ProMotive

Sounds pretty close to my S1 trans, it's about 5000rpm at 80mph. I'll have to take it apart one of these days and see what gears are in it.

JDM EJ2

Nah, speedometers get set off alot because of bigger/smaller wheels. I used to ball outrageous on 18's and it affected my speed by 5 MPH. I used a GPS to figure that out...

DOHChatchGUY

5th gear-80 mph @4300 rpm-Y21 b16 tranny...if that helps.

dohcdelsol93

99 s4c Si tranny, 70 MPH 4,300ish rpms, your tranny is fine

When driving 80mph+ i get less MPG than I do in the city

Frickr

why not get a GPS or a cop to measure your speed. see if it is your speedo off. if so adjust from there. if not, trouble shoot some more.

any cop will radar your speed to check your speedo. and it wont matter if your speeding. i asked to do it in one of my cars, i flew past him at 80 mph when my speedo said 50. (changed rear ends). they wont be a dick about it if your wanting to know.

.Grimace

wow so many people are coming in here thinking it's a b16 tranny... he never stated if he kept his b16 tranny or if he is using a b16b tranny. if it's the b16b tranny yes it's normal. well it's normal either way.