Let me start out by saying I love this car, I’ve put almost a thousand miles on it already. So far it’s been everything I had hoped for. However being new to the RX-8 and rotary engines in general I had a few questions for you guys. When shifting into gears 1-3 an occasional loud thump can be heard. Also during hard acceleration at 7500 RPM the engine just seems to hang for a second before continuing on. Any comments or thoughts would be appreciated.

Here are some pics.

http://www.rx8club.com/attachment.php?attachmentid=75010&stc=1

http://www.rx8club.com/attachment.php?attachmentid=75011&stc=1

man that is sexy!!

7500 rpm thing might be normal, i dont know about the clunk from 1-3, why dont you have the dealer check it out?

Is that a shinka?

No it's a VR with grand touring. Can anyone explain why the engine lags at 7500 RPM?

its a velocity red. no shinka b-pillar.

can you explain the gear 1-3 shift problem? is it when you clutch in? when you shift? or what?

It usually occurs when putting the car in gear at a stop when the engine is at idle. However it also can occur when shifting up into 2nd or 3rd.

does it happen all the time?

Not all the time.

Where does the thump come from? If it's the gearbox, it's normal while the transmission fluids are cold. Dunno about the lag, have your dealer check it out. Sometimes it takes a 'crunch' for me to get in 1st gear, and 2nd sometimes. Changing the transmission fluid to something better like Redline or Royal Purple would definitely help, I need to get that done.

Nice color choice, btw

the ist gear clunk/thump is related to the tranny being cold but can happen even when warm. its just the synchros doing their job. changing to a better fluid as mentioned above will take care of it.

the hesitation can also be attributed to a cold engine. other causes could be fouled plugs, misfire etc. but generally those would cause a CEL.

I’ll start paying better attention, it might only make the noise when it’s cold. I'm really surprised about the lag, it just hangs for about 1/2 sec but it's really noticeable in the sound of the engine and the tach. I'll play around with it a little, try different gears see if that makes a difference.

I have the same issue when shifting from N-1 or 1-N-2. Mostly starts after I've driven 30 - 40 miles. And happens when the car is at rest. Will take it to the dealer some time.

Normal operation.

from http://www.rotaryengineillustrated.com/renesis.php

Variable Fresh Air Duct (FAD): The High Power specification engine mated to the six-speed manual transmission incorporates a variable fresh air duct in addition to a large, low resistance air cleaner. At about 7250 rpm, a shutter valve opens to shorten the intake manifold upstream of the air cleaner. The shutter valve works in tandem with the variable intake valve to boost torque and power at high engine speeds. The fresh air duct is partially inserted into the air cleaner and enables an optimal length intake system by valve opening/closing.


BTW, congrats on your new car. Beautiful color, too.

That tint has to be illegal in most states!

the 7500 rpm is likely your last staged ports opening... has been seen on 6port rotary for long as I can remember.... its a time intensive tuning thing or just live with it thing... some may be more noticeable than others. Could also be a minor grounding issue... when those last injectors kick in with the ports it could cause a minor ground issue to be more substantial.

Mommy, what does VR mean?

^velocity red?

The thump is normal.

7500 rpm just make sure you have the latest flashes.

FYI: The flat spot you may feel might be in your head because you are expecting some kind of vtec like boost, the rotary engine doesn't have that. It just pulls to redline very evenly.

Yes, I have that same thud as well. It doesn't bother me though. I didn't really even notice it until right now.

With exception to the tinted windows externally that is my car to a T.

I am debating whether or not to tint the windows. That does give me a nice look at the difference. Looks nice!!!

Wast the last flash released in 05? His 06 should have all the new flashes direct from the factory.

That tint has to be illegal in most states!


Yes it's illegal here in CA unfortunately. There was no thump today although it is about 15-20 degrees warmer today. I think you guys are right about the transmission being cold and causing the noise. I tried reving in different gears today and got some interesting results. Starting in 1st and shifting at 8000 to 2nd and then shifting at 8000 to 3rd the engine delivered a smooth increase in power the whole way. However already moving in 3rd and flooring the car, the RPM increased to about 6250 and then paused for about 3 seconds and then continued to 8000 at which point I shifted. WTF is that??? That doesn’t seem like normal engine operation. I had to hurry home so I didn’t have a chance to repeat with the same conditions. Maybe because the car is new I'm being paranoid but almost 3 sec lag doesn’t seem normal.

Changing the transmission fluid to something better like Redline or Royal Purple would definitely help, I need to get that done.RP will help out a lot more than RL for cold starts. RL was just as smooth once everything's going, but after switching to RP, it's smooth even before the fluids are warmed up. I'm going to be sticking with RP from now on...

Not all the time.Most new owners also complain about a loud thump sound when they start up the car and start it moving... but it doesn't sound like it if you're hearing it when you get up to 3rd gear.

Where does the thump come from? If it's the gearbox, it's normal while the transmission fluids are cold. Dunno about the lag, have your dealer check it out. Sometimes it takes a 'crunch' for me to get in 1st gear, and 2nd sometimes. Changing the transmission fluid to something better like Redline or Royal Purple would definitely help, I need to get that done.

Nice color choice, btw

I plan on changing to Royal Purple this weekend.

I tried reving in different gears today and got some interesting results. Starting in 1st and shifting at 8000 to 2nd and then shifting at 8000 to 3rd the engine delivered a smooth increase in power the whole way. However already moving in 3rd and flooring the car, the RPM increased to about 6250 and then paused for about 3 seconds and then continued to 8000 at which point I shifted.

that sounds like a protection scheme. either engine overtemp or knock related(or both) probably knock. what grade fuel is in your tank? what company?

^
The fuel was from Costco 91 octane, highest grade I've ever seen in CA. Engine temp sensors sits at about 45% so if it was overtemping I had no indication. I tried different gears up to 8K today and everything seemed ok. Not really sure what to think other then change fuel brand/or keep Costco and see what happens.