A bit rich...but my buddy's CBR600 can't keep up!
08-07-2002, 07:13 PM
#1
Burning Brakes
Thread Starter
A bit rich...but my buddy's CBR600 can't keep up!
Hey guys...I haven't posted much in awhile, as I've been working down in Argentina. I was back home for a bit a couple weeks ago, and took the 951 up the Whistler highway while my friend had his older CBR600 along for the ride. First of all, no complaints regarding my cars performance. I had the boost dialled to a pretty conservative 15psi, and my friend couldn't pass me going up the long uphill straights. In the bends, the 951 pulled well ahead of his bike...in fact I had to slow down a few times to let him catch up. 
Anyways, my concern is that I'm running a bit rich. We took turns on the bike, so I had the opportunity to watch the tailpipe of my car as he accelerated through the gears. My car seems to produce a bit of black smoke when you first start it up and idle it (cold or hot). When accelerating, there's a noticable puff of black smoke when you step on it in each gear, and also a flame out the muffler during upshifts. I couldn't smell oil, and it wasn't blue, so I'm pretty sure the smoke was a fuelling issue.
My car has a Garrett T04E-50 trim turbo, HR Stg3 MAF, ARC2 fuel controller, adjustable fpr, 52# injectors, etc etc. I have previously tuned the air:fuel ratios using wideband O2 sensors on both the street and on the dyno, and achieved a PERFECT 12.5:1 ratio under boost, and stoichometric 14.7:1 under cruising conditions.
Okay, now some questions. Why would the car be smoking if the af ratios were dialled in so well? The af tuning was done in February, and it was at least 20 degrees celcius warmer during our drive. Could the temperature difference be affecting my mixtures? Perhaps it's normal to see some black smoke when you first get on the gas, as the af plot does initially start rich, then lean out to 12.5:1 as the rpm's build past 3000rpm. What about the flames, should I be concerned? It doesn't smoke like a diesel, but it is noticeable from behind - is any smoke a bad thing, and indicative of excessively rich conditions? The cost of my engine rebuild is still fresh on my mind, and I'm paranoid about cylinder wash. Comments appreciated.
Anyways, my concern is that I'm running a bit rich. We took turns on the bike, so I had the opportunity to watch the tailpipe of my car as he accelerated through the gears. My car seems to produce a bit of black smoke when you first start it up and idle it (cold or hot). When accelerating, there's a noticable puff of black smoke when you step on it in each gear, and also a flame out the muffler during upshifts. I couldn't smell oil, and it wasn't blue, so I'm pretty sure the smoke was a fuelling issue.
My car has a Garrett T04E-50 trim turbo, HR Stg3 MAF, ARC2 fuel controller, adjustable fpr, 52# injectors, etc etc. I have previously tuned the air:fuel ratios using wideband O2 sensors on both the street and on the dyno, and achieved a PERFECT 12.5:1 ratio under boost, and stoichometric 14.7:1 under cruising conditions.
Okay, now some questions. Why would the car be smoking if the af ratios were dialled in so well? The af tuning was done in February, and it was at least 20 degrees celcius warmer during our drive. Could the temperature difference be affecting my mixtures? Perhaps it's normal to see some black smoke when you first get on the gas, as the af plot does initially start rich, then lean out to 12.5:1 as the rpm's build past 3000rpm. What about the flames, should I be concerned? It doesn't smoke like a diesel, but it is noticeable from behind - is any smoke a bad thing, and indicative of excessively rich conditions? The cost of my engine rebuild is still fresh on my mind, and I'm paranoid about cylinder wash. Comments appreciated.
08-08-2002, 04:23 AM
#2
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That's kind of spooky about the flame, but you do see sprint cars doing that on decel., but that's apples and oranges.
I have read on several posts about modified turbos blowing rich when they gas on it / shift.
Not much help but it's something.
I have read on several posts about modified turbos blowing rich when they gas on it / shift.
Not much help but it's something.
08-08-2002, 09:45 PM
#3
Intermediate
Okay, okay, let's get one thing straight about Ian's BOASTING about losing me on my CBR600 in the twisties and my not being able to pass him up the long hills en route to Whistler!
1) I WAS able to gain ground on him going up hill ... just not as quickly as I thought I'd be able to. Not only that, but at full twist, it took me a good 20 or 30 seconds to catch him, having started from a couple of car-lengths behind (I was giving him a real-time verbal report regarding his smoking, flaming tail pipe over our 2-way radios ... man did that flame look wild!). Let it suffice to say that I could not by any means pull away from his 951.
Oh, and I was NOT on full throttle ... I was just toying with Ian ... Yeah! That's the ticket! That's my story and I'm stickin' to it!
Alright, alright, I wasn't pegged, but I was damned close, so I might as well have been. Man is his 951 impressive!!! Kind of makes me reconsider the $3K (Canadian) that I paid for my bike ... oh wait, that's a trip to the shop for Ian! Suddenly I feel a little better! (Sorry, buddy ... a little too close to home for you, perhaps.)
2) I am admittedly a wuss on my bike, especially on un-tried twisties ... I am deathly afraid of gravel on little-used mountain highways! I am a family man with a couple of kids at home, so I'm pretty tame on my bike for the most part.
Ian, on the other hand, is an ANIMAL!!! He has taken his (former) bike to track days and was far more aggressive on my bike than I will likely ever be! So let the following example be a testament to Ian's car. With Ian riding my bike agressively and really tossing it around, I was easily able to stay on his tail in his 951, in both the straights and the twisties. I'm far more experienced and confident driving aggressively in a car (especially his 951) than on a motorcycle, but I'm certainly no seasoned rallye driver. At any rate, his car's performance knocked my socks off, even when I had it dialed down to 12psi (the car is far better balanced and less twitchy at lower boost). The car felt as though it was pivoting around the seat of my pants, with instant throttle response and plenty of power to keep me out of trouble with a bit of on-demand oversteer.
Sorry for the long-winded post ... just wanted to make sure that you all got a balanced report on our outing! You've done a great job on your car, Ian. Thanks for sharing the driving experience with me.
Cheers,
- Brian
1) I WAS able to gain ground on him going up hill ... just not as quickly as I thought I'd be able to. Not only that, but at full twist, it took me a good 20 or 30 seconds to catch him, having started from a couple of car-lengths behind (I was giving him a real-time verbal report regarding his smoking, flaming tail pipe over our 2-way radios ... man did that flame look wild!). Let it suffice to say that I could not by any means pull away from his 951.
Oh, and I was NOT on full throttle ... I was just toying with Ian ... Yeah! That's the ticket! That's my story and I'm stickin' to it!
Alright, alright, I wasn't pegged, but I was damned close, so I might as well have been. Man is his 951 impressive!!! Kind of makes me reconsider the $3K (Canadian) that I paid for my bike ... oh wait, that's a trip to the shop for Ian! Suddenly I feel a little better! (Sorry, buddy ... a little too close to home for you, perhaps.)
2) I am admittedly a wuss on my bike, especially on un-tried twisties ... I am deathly afraid of gravel on little-used mountain highways! I am a family man with a couple of kids at home, so I'm pretty tame on my bike for the most part.
Ian, on the other hand, is an ANIMAL!!! He has taken his (former) bike to track days and was far more aggressive on my bike than I will likely ever be! So let the following example be a testament to Ian's car. With Ian riding my bike agressively and really tossing it around, I was easily able to stay on his tail in his 951, in both the straights and the twisties. I'm far more experienced and confident driving aggressively in a car (especially his 951) than on a motorcycle, but I'm certainly no seasoned rallye driver. At any rate, his car's performance knocked my socks off, even when I had it dialed down to 12psi (the car is far better balanced and less twitchy at lower boost). The car felt as though it was pivoting around the seat of my pants, with instant throttle response and plenty of power to keep me out of trouble with a bit of on-demand oversteer.
Sorry for the long-winded post ... just wanted to make sure that you all got a balanced report on our outing! You've done a great job on your car, Ian. Thanks for sharing the driving experience with me.
Cheers,
- Brian