Throttle Hesitation

Hey guys, I've been a member over on the other forum for a while now, but things have been pretty quiet over there recently.

I've been noticing over the past couple months that when I go to pass people, on highways, at part throttle, the car will get to about 4,500 rpm's, dip down to around 4,000, then accelerate again.

It's hard to catch on the accessport since it happens randomly and I don't always have the AP hooked up. But, like i said, part throttle acceleration. I rarely go WOT when passing on the highway. Most of the time it's 4th or 5th gear. I caught it today in 4th.

Here's a data log to look at. I appreciate any help.

Mods are in sig, but if you can't see them i have: jbr power path stage 2 intake with TIP, autotech internals, and UR testpipe. I'm tuned by Freektune on an e33 map. Other mods are Denso ITV-20 plugs, throttle body gasket, and full EGR delete / block off plate.

 

Disclaimer: I am a newb so I'm probably wrong but my initial gut feeling is that with an E33 map (increased octane) and upgrades fuel pump delivery that fuel to the engine, the itv-20 plugs are the weak link here which is why most people run the one step colder plugs (ITV-22). I wish i could look at your data log and provide a more educated answer.

 

thanks brainbot, any feedback is appreciated. i'm going to check the plugs today. from what I've read, i won't need one step colder with my mods. I may have even asked Justin while tuning. Waiting to hear back from him. When I do, I'll mention it.

 

I had issues with hesitation and it came down to plug gap. Go check em. Easy peasy.

 

thanks Raider. I checked the gap on the denso's, and all were about .030. i swapped them out for 1 step colder NGK's and gapped them to around .028. the hesitation isn't as apparent, but it's still there. it kind of feels like the clutch is slipping, just not sure how. hopefully justin will have some insight.

 

Bad ignition coil perhaps?

Sent from my SM-G930T using Tapatalk

 

justin (@ freektune) says it looks like clutch slip since the mph still climbs as the rpm's drop.

does anyone have any experience swapping out the clutch? i see edge has the oem speed clutch in stock and offers a fidanza light weight fly wheel to go along with it. would i need the fly wheel? do i only need just the clutch?

i realize i won't really know until the tranny is off, but if i could save some money/time, i'd like to of course.

thanks guys. @Raider;

 

what year and how many miles are you at? how long do clutches usually last on these cars?

 

I have a 2008, and just hit 70k this morning. I've been noticing the slip for a couple thousand miles. The car still drives and shifts perfect though, which is why I thought maybe the extremely hot weather here in Houston was affecting the tune. Not sure how long the stock clutch should last. I know some guys are modded more than I am, and they're pushing over 100k on the stocker.

 

Don't buy a another stock clutch, upgrade to a 6 puck.

 

@Gandalf; what would be the benefits of a 6 puck? i've read the stock clutch is more than capable of handling my mods. i may go bnr s3 down the road, but even then, 350 hp max?

i'm still trying to research if it's even the clutch that's the issue. i have no problem shifting and it still feels as good as day one. i've been reading conflicting info. some say if the clutch were slipping, the mph would be going down and rpm's going up, which was my logic. i'm trying to come to the conclusion that the mph going up while rpm's go down is a clutch issue.

 

You'd get more chatter, more bite, and a lower lifespan.

YMMV, of course, but I'm at 143k on the OEM clutch and have been putting down >300awtq for the last 70k miles, the last 30k of which have been with a BNR S3 hanging off the backside of the motor.

IMNSHO (In my not-so humble opinion), there's no reason to get an aftermarket clutch with a reduced lifespan unless you're planning on putting out more than 400wtq.

 

yeah, i'm gonna go with a stock clutch and fidanza light weight fly wheel. if i need to.

 

@Vansquish @Gandalf what about something like this http://www.advancedclutch.com/zx5-hdss , not a 6 puck but I've heard good things

 

That might be fine, but I have only one point of reference, and that's the OEM setup.

Seeing as I haven't had my clutch go out yet, it's putting up with the power my car is putting down, and it's a gigantic PITA on the MS6, I can't see any reason to replace it with anything other than an OEM clutch unless I build the motor and start hunting for serious power gains.

Furthermore, even if it's supposedly designed to have a "Longer friction life, extended by ACT's exclusive diaphragm design", the question is: longer relative to what? I want my clutch to last as long as possible, so I'm going to go with the most reliable, longest-lasting system I can find.

 

I, too, would stick with the stock clutch for anything BNR S3 or less. It has been proven to hold the power reliably and for long periods of time. Especially if your car is a daily driver. IMO the stock clutch is the best bang for the buck and it can be regularly found for pretty cheap on Amazon.

If you do plan to upgrade though, a few people around me have really liked their Southbend clutches with their S3 + meth + E85 setups. They are all in the ~400 whp/~450 wtq range though and needed something a little heavier duty. Just might be another option to look at if you decide against OEM, though I think @Vansquish's experience with his stock clutch proves that upgrading just for the sake of upgrading isn't always better.

 

I destroyed my stock clutch with 320whp. If your stock clutch is fine at 350WHP then you are driving like a girl.

 

Either that, or . . .

I actually know how to drive a stick without destroying the clutch.

I have also taught two of my girlfriends how to drive stick on this vehicle, starting at around 70k miles. They haven't managed to destroy the OEM clutch either.

 

My clutch was wasted by 85K or so last year. Maybe 90K. I was granny shifting when I shoulda been double clutching like I should, however.

 

Im at 93k on the stock clutch, and i know it was smoked bad by a friend. still holds and gets beaten at the 1/4 mile