when i had my previous gsr, 5th gear at 80mph would be exactly at 4k rpm. i sold

it a while ago and got a new one.

my new gsr goes 80mph at about 4100-4200 rpm in 5th gear. what could be wrong

with it? the previous owner use to put 87 octane in it and 5w40 oil.

when i bought the car, i replaced the clutch and pressure plate and put in mobile 1

oil and clean my gas tank with those techron bottles and only use 91 octane.

any inputs?

 

Your tach could be off, which is the most likely.

Although, the previous owner using 87 octane in a 91+ ONLY car could cause damage far worse than your revs being off by a 1,000 or two.

 

motor is probably harmed by using the 87 gas. god knows how long he used it for.

 

hes had the car for about 3 years.

could anything be wrong with the valves? should i get my valves adjusted?

Belts?

he told me his uncle changed the belts but he didnt have any paperwork. btw he

didnt know anything about the car, thats why he used 87 octane. he didnt even

know what vtec was.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LTgsr &raquo;</TD></TR><TR><TD CLASS="quote">he didnt even know what vtec was.
</TD></TR></TABLE>
He's not alone.........

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtpktz. &raquo;</TD></TR><TR><TD CLASS="quote">Your tach could be off, which is the most likely.</TD></TR></TABLE>

Yes, or the speedometer.

Anyone else suggesting that the issue has <u>anything</u> to do with improper fuel, engine damage, etc. is 100% incorrect. It wouldn't matter how "damaged" the engine was, if it was spinning at a certain RPM (and assuming the clutch is fully engaged), there is only one corresponding road speed per gear, and that is determined by the transmission ratios and the tire size. Conversely, even with a built, 400 whp turbo motor, if you were running the stock transmission, you'd still be moving at the same speed per RPM as you would with a stock setup.

 

what size tires are you using? stock spec tires are 195/50/15. The size of your tires play a big factor in speed and rpm's. with my 205/45/16 at 4000 rpm's i would be going 83-84. but speedo showed i was going 80mph. i tested it one one of those police radar things they have on the side of the freeway sometimes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lauj87 &raquo;</TD></TR><TR><TD CLASS="quote">what size tires are you using? stock spec tires are 195/50/15. The size of your tires play a big factor in speed and rpm's. with my 205/45/16 at 4000 rpm's i would be going 83-84. but speedo showed i was going 80mph. i tested it one one of those police radar things they have on the side of the freeway sometimes. </TD></TR></TABLE>

The tires do indeed play a role in actual speed, but I believe the poster is asking about indicated speed, which wouldn't change regardless of the tire size.