Low power during launch

The past few autocrosses I've noticed my '99 seems to 'bog down' when launching at the start of an AX run. It kind of feels like the clutch is slipping, but I've tested the clutch with the high gear/low speed/uphill scenario and it's not that. There are no other symptoms that I can think of when this happens either.
It only seems to last a few seconds and then the power ramps up and engages. I really haven't even noticed it doing this on the street, but I usually don't rev up the RPM's before taking off on the street. Any ideas?

Sounds like the clutch to me. My clutch would slip a little on launch but was fine at speed. I dont know if this is typical of 99/00's. My clutch never did fail, but was a little jicky at launch.

Chris

:shock: When I first saw this thread, I read it as "Low Power During Lunch"... I was going to suggest eating more. :lol:

It sounds like you are experiencing what I did prior to replacing my clutch. I take off quickly from stoplights, but never had any slip or hesitation. But at AXs -- where I admittedly push it a lot harder -- the clutch would slip. And a WOT I'd sometimes get a little slip when I shifted from first to second gear, particularly at Pennington, where the grip is pretty good.

Stevan told me that the clutch was not worn out, rather is was so badly glazed that at high launch is would simply slip. I'm not sure what would have caused the glazing (no, I don't rest my foot on the clutch when driving or sitting at a stoplight... at least no more than I've done with the other 5 or 6 manual transmission cars I've owned), but the problem was solved with the new clutch.

You have the Miata Traction control turned on. aka Air conditioning. IT always bogs with the AC on. Sorry Samm, I really don't know what that is either. Could it be a heat soaked intake or engine. Back to back runs just takes the power out of the motor and clutch.

So if you rev it up to let's say 4,500 RPM and dump the clutch what does it do?

I noticed your slow launches at the S2K event but just figured you were being easy on the car.

Quote:

---

Originally Posted by sammm

The past few autocrosses I've noticed my '99 seems to 'bog down' when launching at the start of an AX run.

---

Wouldn't the engine wind up (i.e. increase revs) if the clutch is slipping? Not Bog Down (i.e. lack of power)? Bogging down under WOT would indicate an injector/fuel issue to me.

But then... what do I know... right?

Quote:

---

Originally Posted by POS Racing

I noticed your slow launches at the S2K event but just figured you were being easy on the car.

---

You mean he was being a :cat: ?? I agree with Dave04 though, wouldnt the engine rev up if the clutch was slipping. Maybe you are just not slipping the clutch enough. Just bogging slightly. Or does it feel like the car is doing it? What does it do if you start from just off of idle while rolling and floor it. Does the power feel pretty linear?

Thanks for the replies guys. When it is 'bogging' the RPM's don't go up and it doesn't happen consistently either. A few launches at S2K felt 'normal', but a few others had that 'slow to wind-up' feeling. When the power does come on, it feels linear with no misses or any other weird symptoms.
Like I said, I've tried lugging the clutch on a hill but it's not slipping. I'm thinking it's fuel (or lack thereof) related.

Quote:

---

Originally Posted by Majik

You mean he was being a :cat: ???

---

Yeppie! :flower:

Have you Seafoamed this car Sammm??

Quote:

---

Originally Posted by POS Racing

! Have you Seafoamed this car Sammm??

---

No I have not. Maybe I'll try that and a new fuel filter and see if it helps.

Have you changed to grippier, or oversize tires/wheels? Tires with more grip will cause the car to bog on hard launch. You need a higher launch RPM to overcome that. Also, if you changed to taller, wider wheel/tire combo, you have effectively changed the gear ratio that the car may not have enough power to overcome on inital takeoff... :bom:

I found on Saturday that i had to run higher than normal rpm launches to avoid the evil bog monster. Saturday afternoon, I had to launch about 500 rpm lower than in the morning... It's probably more a matter of how much grip you're getting at any given time than any "fault" of the car.

No oversize tires or wheels. Still running stock 14"s with Azenis. I'll have to try some test launches from stop lights this week and see what happens. That is interesting that a grippier tire would make the car feel slow at take off. Makes sense, but still interesting.

Quote:

---

Originally Posted by sammm

No oversize tires or wheels. Still running stock 14"s with Azenis. I'll have to try some test launches from stop lights this week and see what happens.

---

Maybe you just need to carry a puddle of water around with you...

Quote:

---

Originally Posted by tailchaser

Maybe you just need to carry a puddle of water around with you...

---

Ouch:nutkick: