Chronos

I have two problems...I started to notice about a week ago that whenever I switch into 2nd gear at 7300rpm the car would shake a lot, and I could see movement in the shift ****. 2nd gear is also most times hard to shift into and I can feel through the **** that the gears don't mesh smooth most of the time.

Problemo dos...This one's a bit more severe!

I just got my Apex GT spec exhaust (the HUGE 4" thick one) installed last week and when I got the car back I noticed that the exhaust was rattling. I figured that the guy didn't install it right or something because it sounded loose. Aside from that, I was also hearing it back fire, pretty subtly during normal or semi fast driving...but when I redline it (and the engine cuts out) it makes a HUGE series of backfires. I did just that tonight and apperently something went pretty wrong, because now I can hear the exhaust noise coming from right under the middle of the car. It sounds pretty much like something came loose or broke in the exhaust track.

So, why do you think this happened and what can I do to prevent it from happening again?

HELP IS MOST APPRECICATED

Rexafied

1st problem: Probably gear synchros.
2nd problem: Get under the car and look, probably missing bolts.

P'cola FD

You are pobably either missing bolts, or need to tighten the ones on the exhaust. As far as the transmission, the going into gear could be synchros, ormaybe your clutch is going south. As far as the shifter bobbling back and forth, you may want to check out your PPF for cracks.

j9fd3s

iTrader: (3)

is it possible you are hitting boost cut?

mike

OptusX4

Yeah, what are your mods? If you've got a clear-through exhaust, with no ecu, that could either be boost cut, or backfiring. Backfiring is no big deal, and is kind of a healthy sign, means you're nice and rich. If you're hitting boost cut, I wouldn't drive the car until you get it taken care of, boost cut's at what 14psi? 16? I forget, and if you're boosting that much with no ecu, on the stock twins, you're risking a new engine and turbos.

P.S. If not clear through exhaust, and it's backfiring, then check your plugs.

reza

PowerPlant Frame cracked or loose?

Chronos

hrm...I just got a new ACT S/S clutch installed, I'm thinking it's prbly the gears, do I just buy the 4.30 ring&pinion to replace them?

As for the second problem, I'm running RE amemiya intake, dp, Cat, and 3.74" Apex GT spec exhaust...I'm pretty sure it does backfire during slightly hard runs, but If I don't shift at 7400 and hit the redline it makes a really shitty sounding series of backfires (like 6 a second) that's what happened just before I started hearing the exhaust noise come from under the car instead of the back...

Chronos

btw, the car is over boosting like 12-13psi at times (sometimes it stays at 10psi)

rx7speed811

if your shifter is dancing around, you might want to get under your car and check out the power plant frame. it might be cracked.

do you have an upgraded ecu? i hope so with that exhaust setup...

you can always get a friend to stick his face right at the back of the exhaust pipe and look inside when you rev it up and backfire to see where the noise is coming from

Chronos

I actually don't have enough money right now for an ECU so I went to home depot and bought a valve for the vacume lines so I thcan adjust e boost like that (haven't installed it yet though)...my friend said that unplugging the battery then replugging it might let the ECU reload and automatically detect the increased airflow and compensate with increased fuel delivery. What do you guys think?

reza

The ECU in our car does not have airflow sensor. Thus it never compensate for increased airflow.
Put in that manual valve, and close the wastegate more.
You will do good with it, also prevent yourself from blowing up your engine
And check your PPF(PowerPlantFrame).
Put the car on a lift, and look around.

Wade

iTrader: (1)

You shouldn't be hitting boost cut from high RPMS until about 8000 RPM, not 7500. If you are getting the backfires at 7500 RPM then it is likely overboost fuel cut, which seems to always happen at 500 RPM intervals.

Wade