Installed MREV2 and 5/16" Isothermal Spacer
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From: Tulsa, OK
Last edited by onagao; Apr 2, 2009 at 03:08 PM.
Thread Starter
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From: Tulsa, OK
I left my stock airbox with my brother out in New Mexico. I've heard varying reports about the effectiveness. I'm thinking that with a tune, the Popcharger and others are more effective than just a drop-in. Without a tune, I'm thinking the ECU over-corrects and/or adjusts for the intake mod in such a way that you might see little to no gain (or even losses in some extreme cases).
I gave it a lot of thought when I discovered the whole issue, and just sided with the popcharger out of laziness. However, now that I just got my car professionally tuned by Uprev (+16whp @ 6600rpm!), I think I'm probably better off. If you could show me something that suggested otherwise, though, I would definitely consider a switch.
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From: Tulsa, OK
Official update to my running lean situation:
Despite the fact that we couldn't find an exhaust leak in a brief search, the degree to which the dyno sniffer said my car was running lean was inaccurate. After getting a hold of Uprev's Osiris Standard w/ Cipher, I was able to monitor the true A/F ratios. As it turns out, it was running lean - perhaps dangerously so - at least undesirably so. However, instead of the 16-17 that the sniffer indicated, it was more 14-14.8 or so. With all of my mods, that's not surprising at all. If the sniffer had told me that initially, I would have been like, "Hmm... Okay." instead of freaking out.
At any rate, the trip down to Austin where Uprev gave my car a proper dyno tune, these new A/F readings were confirmed. Then they waved their little magic wand over my car and gave it a lot more power. Now I'm running with over 16whp more at 6600rpm and an A/F ratio of 12.9 across the board. I am a happy camper.
All said and done, I have nothing but the best things to say about Motordyne and their products. The MREV2 and Spacer are easily the best bang for the buck bolt-on set that I put on my car. Kudos to Tony and Co. for making a fantastic product. You have a very happy customer in me.
Despite the fact that we couldn't find an exhaust leak in a brief search, the degree to which the dyno sniffer said my car was running lean was inaccurate. After getting a hold of Uprev's Osiris Standard w/ Cipher, I was able to monitor the true A/F ratios. As it turns out, it was running lean - perhaps dangerously so - at least undesirably so. However, instead of the 16-17 that the sniffer indicated, it was more 14-14.8 or so. With all of my mods, that's not surprising at all. If the sniffer had told me that initially, I would have been like, "Hmm... Okay." instead of freaking out.
At any rate, the trip down to Austin where Uprev gave my car a proper dyno tune, these new A/F readings were confirmed. Then they waved their little magic wand over my car and gave it a lot more power. Now I'm running with over 16whp more at 6600rpm and an A/F ratio of 12.9 across the board. I am a happy camper.
All said and done, I have nothing but the best things to say about Motordyne and their products. The MREV2 and Spacer are easily the best bang for the buck bolt-on set that I put on my car. Kudos to Tony and Co. for making a fantastic product. You have a very happy customer in me.
Official update to my running lean situation:
Despite the fact that we couldn't find an exhaust leak in a brief search, the degree to which the dyno sniffer said my car was running lean was inaccurate. After getting a hold of Uprev's Osiris Standard w/ Cipher, I was able to monitor the true A/F ratios. As it turns out, it was running lean - perhaps dangerously so - at least undesirably so. However, instead of the 16-17 that the sniffer indicated, it was more 14-14.8 or so. With all of my mods, that's not surprising at all. If the sniffer had told me that initially, I would have been like, "Hmm... Okay." instead of freaking out.
At any rate, the trip down to Austin where Uprev gave my car a proper dyno tune, these new A/F readings were confirmed. Then they waved their little magic wand over my car and gave it a lot more power. Now I'm running with over 16whp more at 6600rpm and an A/F ratio of 12.9 across the board. I am a happy camper.
All said and done, I have nothing but the best things to say about Motordyne and their products. The MREV2 and Spacer are easily the best bang for the buck bolt-on set that I put on my car. Kudos to Tony and Co. for making a fantastic product. You have a very happy customer in me.
Despite the fact that we couldn't find an exhaust leak in a brief search, the degree to which the dyno sniffer said my car was running lean was inaccurate. After getting a hold of Uprev's Osiris Standard w/ Cipher, I was able to monitor the true A/F ratios. As it turns out, it was running lean - perhaps dangerously so - at least undesirably so. However, instead of the 16-17 that the sniffer indicated, it was more 14-14.8 or so. With all of my mods, that's not surprising at all. If the sniffer had told me that initially, I would have been like, "Hmm... Okay." instead of freaking out.
At any rate, the trip down to Austin where Uprev gave my car a proper dyno tune, these new A/F readings were confirmed. Then they waved their little magic wand over my car and gave it a lot more power. Now I'm running with over 16whp more at 6600rpm and an A/F ratio of 12.9 across the board. I am a happy camper.
All said and done, I have nothing but the best things to say about Motordyne and their products. The MREV2 and Spacer are easily the best bang for the buck bolt-on set that I put on my car. Kudos to Tony and Co. for making a fantastic product. You have a very happy customer in me.
I know...I'm being a smart ***.As for your intake, given that Z's stock intake is highly tuned for resonance frequencies, your best best is the stock box. It's not just about the flow. The resonance is also very important and that you can't measure that without sophisticated equipment. Just ask Motordyne why 5/16 space is the right size for their space er: resonance for optimal flow.
Glad you worked out the details.
Its not just about flow. Its resonances. You can even think about it as being acoustics. IE the sound of the resonating runners in combination with the plenum chamber.
An interesting observation:
When the upper plenum is removed and you have access to the lower plenum (which is bolted to the engine) if you were to gently slap one of the runner inlets it will resonate like a Bongo drum. And it will resonate differently if the associated intake valve is open or closed. The MREV2's bongo sound is louder and deeper than the REVUP lower plenums bongo sound.
This isn't a way to gauge a manifolds performance... but it does give you an interesting audible connection to the sounds and acoustics going on inside the plenum assembly. And from the sound of the MREV2 and REVUP, you can hear a relative correlation between their different engine tuning frequencies.
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From: Tulsa, OK
Really??
It makes sense, and I'm surprised I didn't consider that beforehand - a mechanical engineering degree is supposed to teach you some things.
Questions:
So reverting to the stock airbox would increase performance even in a heavily modded and tuned situation like mine?
Also, would a lot of whistling coming from the Popcharger/Intake at half throttle be a sign of poor resonance detrimentally affecting the performance? If so, I'm switching ASAP, because my car whistles like it's turbocharged now that I have the MREV and Spacer.
I mean, I will gladly, happily, and excitedly take any professional advice on the matter.
It makes sense, and I'm surprised I didn't consider that beforehand - a mechanical engineering degree is supposed to teach you some things.
Questions:
So reverting to the stock airbox would increase performance even in a heavily modded and tuned situation like mine?
Also, would a lot of whistling coming from the Popcharger/Intake at half throttle be a sign of poor resonance detrimentally affecting the performance? If so, I'm switching ASAP, because my car whistles like it's turbocharged now that I have the MREV and Spacer.
I mean, I will gladly, happily, and excitedly take any professional advice on the matter.
I much prefer the stock air box over after market intakes. The aftermarket intakes typically draw in a lot of hot air from the engine compartment when you are stopped or moving slowly... and hot air quickly reduces power.
Hot air induction at a stop light means you will experience about a ~15 HP reduction for about the first 4 seconds of a launch.
And yes, please send me the data files!
Hot air induction at a stop light means you will experience about a ~15 HP reduction for about the first 4 seconds of a launch.
And yes, please send me the data files!
Last edited by Hydrazine; Apr 3, 2009 at 11:03 AM.
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From: Tulsa, OK
I much prefer the stock air box over after market intakes. The aftermarket intakes typically draw in a lot of hot air from the engine compartment when you are stopped or moving slowly... and hot air quickly reduces power.
Hot air induction at a stop light means you will experience about a ~15 HP reduction for about the first 4 seconds of a launch.
And yes, please send me the data files!
Hot air induction at a stop light means you will experience about a ~15 HP reduction for about the first 4 seconds of a launch.
And yes, please send me the data files!
Based on your professional experience, you would say that even with a tune, a K&N drop in with the stock airbox would be better than a Popcharger?
That bit on the launch is appalling. I've already asked my brother to hook me up with my old airbox the next time we see each other.
I'll see if I can't drop by the dyno shop tomorrow and bring my flash drive. How would you like me to send them - just post them or email?
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From: Sherman Oaks, CA
So I got some good news and some bad - potentially very bad - news.
First, the good. As expected, HP and TQ numbers went up significantly throughout the midrange. I don't have exact calculations as to how much was gained in the midrange... because I was too distracted by the bad news to ask. You can look at the chart and get a rough estimate as to how much they were, though.
New numbers:
262.10 WHP
252.47 WTQ
[VIDEO]
[BEFORE/AFTER CHART IS ATTACHED]
So that's the good news. The power and torque increases are right up there with Motordyne's advertised numbers. I'm actually quite happy with them.
Here's the bad news...
My car is running EXTREMELY lean (around 16). I don't have any previous A/F ratio data, so I don't know if this is a new development. Regardless, the numbers are alarming. The guy who was running the test said that it was extremely dangerous to run this lean - that within months, my rings could go out, etc. He said he definitely wouldn't get on this car in any hard way, given the situation.
So here I am with a bittersweet feeling. On one hand, the numbers met my expectations, and I'm happy. On the other hand, I could have a very serious issue on my hands.
So please, anyone, help me out here. I don't know how to deal with a problem like this. I have a few options that I can think of:
1) My brother suggested that I reset the ECU, even though I had the negative end of the battery disconnected for several hours - long enough to erase my radio presets (which I thought was an indication of ECU reset).
2) I could go in the direction of an ECU reflash - Uprev Osiris or Cobb Tuning AccessPort.
3) I could follow the advice of the guy at the shop and look into a new fuel injection/management system.
I really don't like #3. #1 doesn't seem like it hasn't already been done. And #2 will cost a substantial amount of money. These are the only 3 things I can come up with, and I don't know if any of them will help. That's why I'm asking anyone and everyone for some advice.
Please help.
First, the good. As expected, HP and TQ numbers went up significantly throughout the midrange. I don't have exact calculations as to how much was gained in the midrange... because I was too distracted by the bad news to ask. You can look at the chart and get a rough estimate as to how much they were, though.
New numbers:
262.10 WHP
252.47 WTQ
[VIDEO]
[BEFORE/AFTER CHART IS ATTACHED]
So that's the good news. The power and torque increases are right up there with Motordyne's advertised numbers. I'm actually quite happy with them.
Here's the bad news...
My car is running EXTREMELY lean (around 16). I don't have any previous A/F ratio data, so I don't know if this is a new development. Regardless, the numbers are alarming. The guy who was running the test said that it was extremely dangerous to run this lean - that within months, my rings could go out, etc. He said he definitely wouldn't get on this car in any hard way, given the situation.
So here I am with a bittersweet feeling. On one hand, the numbers met my expectations, and I'm happy. On the other hand, I could have a very serious issue on my hands.
So please, anyone, help me out here. I don't know how to deal with a problem like this. I have a few options that I can think of:
1) My brother suggested that I reset the ECU, even though I had the negative end of the battery disconnected for several hours - long enough to erase my radio presets (which I thought was an indication of ECU reset).
2) I could go in the direction of an ECU reflash - Uprev Osiris or Cobb Tuning AccessPort.
3) I could follow the advice of the guy at the shop and look into a new fuel injection/management system.
I really don't like #3. #1 doesn't seem like it hasn't already been done. And #2 will cost a substantial amount of money. These are the only 3 things I can come up with, and I don't know if any of them will help. That's why I'm asking anyone and everyone for some advice.
Please help.
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Joined: May 2008
Posts: 548
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From: Tulsa, OK
While it was high, running in the 14's at its worst point, it wasn't quite as bad as the 16 I had thought. It's just one of those things that happens with some of your AFR "sniffer" senors at the tail of the exhaust - if you have a leak of any kind, it can throw the entire reading off.
So all that being said, you can expect the mod combination to lean things out a bit, but it's not that bad. I think it would still be a good idea down the road to get a tune - you stand to gain gobs of torque and horsepower while ensuring that your car is running as safely and reliably as possible. Just my two cents on the matter.
