[onETon]

Ok, this is ultra embarrassing to admit, but I'm at a lost with this car. Between my "I suck at the track in this car" thread and this thread, I bet you guys think I'm the biggest moron by now. :facepalm

Background:

I've been driving manual cars since the age of 15. I've probably stalled in my new (to me) 07 Exige S in the last 400 miles than I have in any vehicle in the last 10 years, combined. Probably around 6-7 times, total.

I asked the PO (Mr. Know, who's been very helpful) if it had an aftermarket clutch because it has the characteristics of a pucked clutch. I have a six puck clutch and lightened flywheel in another car so I recognize the engagement behavior. He assured me that the clutch was OEM, but did mention that Elises and Exiges drive very different. I've only driven two Elises (one that was mine) and only one Exige (current) so I don't have many references. But during the first test drive I already noticed that the Exige drives way different.

Personally, this is how I drive manuals. The subset of steps is as follows (assuming all equipment is up to snub):

-In gear, I let the clutch go until I know it's engaging. I usually wait until the car begins to lurch forward or when it starts to shake
-I let the clutch go more ever so slightly and keep my foot there to build momentum
-When enough momentum is built, I let completely off and start giving gas
-This is how I normally drive manuals unless if on an incline or if I need to take off a little quicker than usual in which case I'll give it a little more gas.
-I personally try to avoid throttling while on the friction point if not necessary

This is what happens with this car using my same approach:

-At the friction point the car begins to roll normally
-I let off a bit more and keep my foot there to continue building momentum
-If I keep it there too long, the RPMs jump from 0-1k and it dies very softly
-If I give it gas at this point nothing happens and it dies eventually after some back and forth
-If I let go at a faster rate, the car jumps (read: almost launches) to about 1.5k RPM

It's hard to explain but the only way I can put it is that this car has three phases on the clutch:

-normal friction point where car begins to roll
-"middle" point where it wants to die with or without gas
-"actual" friction point where the car catches hard and fast, and propels you

So I was experimenting and this is what I came up with:

-if I drive "textbook" manual, ease out on clutch, and give gas when clutch is engaged, it stalls
-it drives normal if I "ride" (I'm not really riding) clutch and let go quickly
-it drives the best if I give it NO gas and let the clutch go faster than normal to bypass the "middle" point as fast as I can and hit the "actual" friction point

Is this an Exige thing? Is it a drive-by-wire thing? Is it a Gotham ECU thing? Drivetrain thing? Car has no drivetrain mods, no TC, and no LSD. Side note that may be relevant, I noticed that when I blip the throttle to rev match, 40% of the time it doesn't rev. I hear the whoosh of air and the butterflies opening quickly, but the RPMs don't jump as fast or at all. Almost like a lag.

It's really affecting the way I drive my other manual cars. Just yesterday, after driving the Exige all day, I hopped into my Miata with my girlfriend and kept dropping the clutch too fast and bucking us around. Sorry for super long post, very hard to describe and it's frustrating me. anic:

P.S. Also please stop imagining me as Mr. Bean:


I'd like to think I'm a pretty good driver...

 

[LostPawn]

Maybe I’m reading your approach wrong but it sounds like you expect the idle of the car to get you moving from a dead stop with a manual transmission. This is not how I learned. I’d guess this is why you continue to stall the car and I’m surprised this doesn’t happen more often in your other vehicles. You don’t need to floor the gas but bring up the RPMs some as idle is not likely to support what you are trying to do. Even automatic cars have torque converters to allow the RPMs to climb from a dead stop.

 

[Kazi]

Side note that may be relevant, I noticed that when I blip the throttle to rev match, 40% of the time it doesn't rev. I hear the whoosh of air and the butterflies opening quickly, but the RPMs don't jump as fast or at all. Almost like a lag.

Check your intake cam. Mine was worn out and had a similar behavior. Once I replaced it, rev matching became much more consistent. I also had problems stalling trying to get out of first gear.

 

[bri3d]

Maybe I’m reading your approach wrong but it sounds like you expect the idle of the car to get you moving from a dead stop with a manual transmission. This is not how I learned. I’d guess this is why you continue to stall the car and I’m surprised this doesn’t happen more often in your other vehicles. You don’t need to floor the gas but bring up the RPMs some as idle is not likely to support what you are trying to do. Even automatic cars have torque converters to allow the RPMs to climb from a dead stop.

Agree - onETon's approach sounds like the method that you use on cars with ECU anti-stall systems and fragile clutches, like a Carrera GT.

On cars or motorcycles with lots of rotating mass (heavy flywheel, lots 'o' cylinders/crankshaft) you can often get away with this approach as well, but I've always given the car gas.

I do suspect the N/A v. supercharged difference and/or your Gotham tune could be related, in that the idle map values might be different or the car with the supercharger just needs a little more throttle to stay alive.

Your rev-matching issue sounds possibly related and also worrying - like Kazi mentioned, it could be something like the cam. It could also be a boost leak or a deficiency in your tune. There are occasionally stories about sketchy VF/Goth.am tunes around here. I think it's worth checking that your AFRs and boost pressures are correct and then looking down the bad tune route.

I have an N/A '06 and the throttle is pretty responsive, so I don't think the DBW system is to blame (again, unless something's going on with your tune).

 

[cashxdr]

With the luck you seem to be having with your car. I would let someone else drive it, preferably that has a Lotus, and let them see what it is doing

 

[Swic]

-In gear, I let the clutch go until I know it's engaging. I usually wait until the car begins to lurch forward or when it starts to shake

If you aren't going downhill, you should try giving the minimum possible throttle FIRST or start gassing slowly at the same moment as hitting the friction point. Then don't just drop the clutch, there's a whole range of engagement. That is my experience, I was a horrible student of driving stick because I kept dropping the clutch too fast. It was always terrifying to hear my father-in-law's car go "thump-thump-THUMP" when trying to power through the inevitable stall. Maybe other cars have softer clutches and a stronger idle, but I have not driven such a vehicle before.

 

[onETon]

Thanks for the tips, guys. Just to clarify, this isn't your, "just turned 15 learning on dad's manual car" violent bucking. It just dies ever so slightly.

And I'm not arguing my method of driving is correct, but it has seemed to work with all my cars without stalling. The confusing thing is, even if I did give the Exige gas, it has to be at the right moment, or it stalls. That's what confuses me. If I give it a little gas after the initial bite and before the crazy launch, it just wants to stall. As if the gas input was incorrect or not enough for that exact moment of the clamping.

Ok, the intake cam definitely scares me. Like mentioned there are times when it feels like the gas pedal isn't responding. i.e. when I quickly rev-match or at that exact position of the friction point. I just chalked it up to me not being used to drive-by-wire yet.

 

[bri3d]

Ok, the intake cam definitely scares me. Like mentioned there are times when it feels like the gas pedal isn't responding. i.e. when I quickly rev-match or at that exact position of the friction point. I just chalked it up to me not being used to drive-by-wire yet.

I've noticed that I do have to depress the throttle for ever-so-slightly longer when rev-matching some DBW cars - I think the throttle takes a split second longer to open up than with the direct cable actuation. Of the DBW cars I've driven the Lotus is one of the more responsive ones though.

Again the tune could definitely affect the throttle response in a variety of ways as well so it might be something to look into.

I'd inspect your camshaft because it's pretty quick to look at and preventative inspection never hurts. I doubt it's the cause of your issue, but it certainly could be. Even if your camshaft is worn it's not as scary an issue as it sounds - if it's wiped but your rocker arms haven't been damaged yet, swapping it out is a fairly straightforward couple of hour job. OE cams are dirt cheap, or you could use it as an opportunity to upgrade to a Stage 2 or 3.

I'd then get someone else who's driven an Exige S to take your car for a spin. If their car feels like yours, it's probably just something you need to get used to (give the car a bit more gas sooner). If they think your car is off too, I'd start debugging boost issues and consider a retune.

 

[Kimgt]

I give my car some throttle before letting off the clutch, but exige was my first manual car.

 

[cashxdr]

Practice doing burn outs, then back it off from there

I have the ACT HDSS clutch and it is more of a on off switch than a clutch. Feathering is almost not a option but I am used to it and can be as smooth and any other car.

I just have to give it a good blip of gas and release as the revs climb

 

[Almighty]

Practice doing burn outs, then back it off from there

I have the ACT HDSS clutch and it is more of a on off switch than a clutch. Feathering is almost not a option but I am used to it and can be as smooth and any other car.

I just have to give it a good blip of gas and release as the revs climb

I have the xt/ss ACT clutch in my car. THAT thing is digital.

 

[cashxdr]

I have the xt/ss ACT clutch in my car. THAT thing is digital.

+1

 

[mkzhang]

I also give it gas before I release the clutch, even if its a little bit. The phases of engagement is a bit funky (at least for me) but I've never known the car to be able to get itself to off the line and off the clutch without giving it gas

 

[cprelise]

Is it the Exige S3 the V6 engine ? then it could be the car and not you. You will find a lot about under Evora regards stalling/hiccups that pointing to a faulty engine wiring harness