Fellow SST owners: Is this normal?

[Blugin]

So I bought my MR slightly used to kill some of the depreciation. It has about 18K miles now and has always been bone stock. I cant tell what's up with it though cause it feels awefully odd on the freeway. If I stab the gas in say, 4th gear at about 4500RPMs, the tach will jump for a second then fall back down and the car will take off. It doesn't seem to do this if I roll onto the throttle.

Also, if I'm just full throttle and going through the gears, sometimes when I hit about 5000 to 5500 rpm, the car will act like I let off the gas and the tach will briefly stop rising and then will resume. I don't know if it's hitting some sort of boost spike and then cutting boost (no boost gauge) or it's the SST or the factory tune is just that bad.

I don't know if these issues are normal since I didn't own the car from 0 miles and if I need to take it to the dealer. If it's normal, that's fine and I'll probably end up getting an AP but if my trans is slipping, I need to take it to the dealer.

[5harkology]

Are you in normal and auto mode when you stab the throttle on the freeway?

[Blugin]

Does it in normal or sport as far as I can tell. It's already in gear though when doing it, not shifting which is where the difference between normal and sport comes into play (from my understanding).

[weneversleep]

That doesn't sound normal. I would take it to the dealer and exercise that warranty.

[doibugu2]

I would say the first one is normal. The 2nd issue doesn't seem to be. I've never had a turbo charged car before, so this is all new to me. They do seem to act differently then most other cars I've ever owned.

Take it to the dealer to be safe, it won't hurt to have it checked out. Besides it's free.

[mrMTB]

Blugin, on the first case keep an eye on the gear indicator. The TCU will rev-match when it downshifts, so if you stab the gas and the system determines that it needs to be in a lower gear to deliver the output that the system believes it needs, it will engage the clutch, blip the throttle, downshift, and re-engage the clutch. This sounds like what you're seeing there.

On the other, I agree with the others- go ahead and take it in and see if there is a problem. You might need to get one of the later reflashes to correct that (or it'll go away when you visit Chris and Neil in Plano).

If you're up on the McKinney area, ping me and we can go for a ride in mine to see if you see the same behavior.

[Blugin]

Thanks for the pointers, guys!

The throttle-stab behavior is observed in full manual mode locked in a gear so there's no shifting involved.

I should have mentioned that I have taken it to the dealer and they told me I have the latest ECU revision. (still get horrible mileage though...)

Thanks for the offer, mrMTB!

[gunzo]

Originally Posted by Blugin

Thanks for the pointers, guys!

The throttle-stab behavior is observed in full manual mode locked in a gear so there's no shifting involved.

I should have mentioned that I have taken it to the dealer and they told me I have the latest ECU revision. (still get horrible mileage though...)

Thanks for the offer, mrMTB!

case 1 is normal .. the engine attempts to give you a slightly higher rpm than possible at the lower rpm ranges with high gears .. so it SEEMS like it's slipping .. but its not .. its just programming

Case 2 ASSUMES you still have stock exhaust .. normal because the flapper causes all these issues at high rpms .. very pronounced between 5000-6500rpms especially .. if you listen carefully .. sometimes you can even hear the thumping sounds of the flapper slamming shut and opening again ..

[Blugin]

Ahhh, so it's the internal wastegate flapper? That makes sense. That would mean it's some sort of boost control issue, right? I do have the stock exhaust too- it's all stock.

Very helpful forum!

[mrMTB]

Wastegate flapper, or is does the car have one of those exhaust systems where a flapper makes the exhaust system volume larger during certain conditions?

[gunzo]

Originally Posted by Blugin

Ahhh, so it's the internal wastegate flapper? That makes sense. That would mean it's some sort of boost control issue, right? I do have the stock exhaust too- it's all stock.

Very helpful forum!

Sorry .. wasn't clear here .. mrMTB is correct .. the stock exhaust has a flapper valve that supposedly keeps the noise level down and opens when you need the power to 'freeflow' the exhaust ..

This flapper is your problem .. the spring is too stiff .. it closes when the pressure reduces until it builds up high enough and then it opens up again .. hence your 'surge' feeling ..

[Blugin]

Originally Posted by gunzo

Sorry .. wasn't clear here .. mrMTB is correct .. the stock exhaust has a flapper valve that supposedly keeps the noise level down and opens when you need the power to 'freeflow' the exhaust ..

This flapper is your problem .. the spring is too stiff .. it closes when the pressure reduces until it builds up high enough and then it opens up again .. hence your 'surge' feeling ..

Interesting! What part of the exhaust is that piece in? Is it part of the catback, DP, etc? I guess I could search...

[gunzo]

Originally Posted by Blugin

Interesting! What part of the exhaust is that piece in? Is it part of the catback, DP, etc? I guess I could search...

Stock Exhaust

This is crap.. I can't post the link .. fill in the *** with evoxforums dot com
This probably save yourself alot of $$ and trouble for quite a substantial improvement

[Blugin]

Got it! Interesting... I'll probably buy a catback then if that's what's causing my power drop. It's just very strange feeling.

[strocse]

You need a custom tune, the MR is a useless car without it. Never drive in normal mode car acts like its balls were cut off. dont take your foot off the gas when shifting.