yea so basically my friends 2007 rx-8 feels faster than my 2005 rx-8 GT... Does anyone know wat the difference are betwwen the to?

 

Nope.

 

The weight is gonna be less on the sport

 

You have the leather, sunroof, perhaps more body parts.

Unless you're comparing automatics.

 

yeah... about 200 lbs

GT= power seat, power roof, leather, fogs, DSC, heated seats, bose sound system, etc.

 

The Sport model can be roughly 200 lb lighter than a loaded GT.

The old racing rule of thumb is that 10 lbs weight saved is like gaining 1 HP, so the Sport will feel like it has approximately 20 HP on the loaded GT.

Chris...

 

My guess is the difference is probably closer to about 60-70 pounds.

 

I don't think 60 or 70 pounds would register on the butt dyno. I don't really notice a difference with or without my wife - who's pretty much normal weight - riding shotgun.

I have a friend who weights about 280. The difference between having him in the car vs not is remarkable.

Ken

 

I do notice the difference when my girlfriend, who's 100 pounds, is in the car. Add in the fact that his friend's Sport has a Renesis on the higher end of the production power variation and his GT being a weaker Renesis and that could be where the difference in feeling comes from. Of course, his GT's engine could just be on the way out also.

 

thanks for the info guyZz.. but what do u mean my rensis could be on its way out? and you said his rensis is on the higher end of the production power variation, please explain?

 

No two engines are identical due to production tolerances in manufacturing. If the tolerances line up just right, an engine will produce more power than normally rated which is the thinking behind blueprinting. On the other hand, an engine that has tolerances go in the other direction could produce less power than rated; this is why when a bunch of stock RX-8s are dyno'd, they produce different amounts of horsepower, sometimes varying by quite a bit.

As for your engine on the way out, one of the signs that the Renesis is showing when failing is low compression. Low compression produces less horsepower. You might want to get your engine compression tested.

 

Can i get the compression test at the dealer? And if so can the be consider a warenty issue?

 

its hard to get a test done under warantee....i had it done but thats because i was showing lots of symptoms....but it turned out my compression was high but i had other issues.....good luck finding a local dealer that will do it omar....

 

I'd rather get it done at a reputable rotary shop. I question whether some of the dealers would even know how to do it correctly.

Honestly, if the difference in acceleration between your friend's RX-8 and your's is slight, I'd chalk it down to production variations and the weight difference. Only if there is a very noticeable difference would I compression test your motor.

 

Are you riding as a passenger and driving your car?
Riding always feels faster then driving because your not in control.
Also if it's lighter there is your answer.

 

i was driving it. But i did here that slow starts, loss in horsepower, and some other symptoms (pleasr let me know them if you guys know) are becouse of low compression. so i think i am goin to try and get it tested.

 

if its a 2005 it probably needs new spark plugs. I would replace those before venturing into any other theories mentioned above.

The difference between crappy plugs and new plugs is night and day.

 

You just reminded me about coils also not to mention your engine could've been heatsoaked while his was at the right temperature. Way too many variables. A compression test IS nice to have though just for piece of mind.

 

Yo thanks guyZz for real i guess ill keep u posted on what the dealer says........