What's your engine's "Sweet Spot" (or "Flat Spot")??
02-16-2008, 05:50 PM
#1
What's your engine's "Sweet Spot" (or "Flat Spot")??
Whether you have a naturally-aspirated (NA) VQ30 versus one that is blown, or a totally stock A32 versus one with a mountain of mods, you have probably noticed a point on your tach when your engine's revs tell you it's about to kick some A**.
The flip side is a dead spot where the car seems to be full of sound but not much fury.
If you're ride has no flat spots or sweet spots, and you got the "go juice" all the way up to red line, lucky you.
For everyone else, post your props or flops here. Since I'm sure that we all would like to know how you got rid of any flat spots or got to their sweet spots faster, please describe what you did.
My A32 I30 has a slushbox. It launches like a slingshot when I power brake it at 1,500 RPM, but when it gets to 2k, the engine sort of goes out to lunch with the tranny and the car seems to lag along like a cheapo turbo.
It gets back to business right at 3k and keeps on trucking until it hits the spot where 00VI-equipped VQ's are still doing the Energizer Bunny thing.
I know that the power-braked RPM's might seem a bit low for launch, but dialing in higher revs always lays down more rubber than Nevada's Chicken Ranch.
One of my mods did reduce the lag, but when I hit 40MPH, the car ran about as fast as a Dell desktop but not as far.
One thing that this mod taught me was what happens when you restrict the openings where air has to go, and what happens when you make it less restrictive.
Maybe the TB has TB and like can't breathe in enough cool air? When I punch it, the car revs high way before the tranny wakes up and upshifts, resulting in missing that little break in traffic where you tried to drop on in.
I wonder if ECU controllers reduce or eliminate these flat spots on 95-96 A32's (like Jet and JWT)?
I wonder if they make them for 97-98's?
Any way, speak up and speak out. How much power do you want and how quickly do you want it? Do you notice any lags that bug you? Feel free to speak freely.
The flip side is a dead spot where the car seems to be full of sound but not much fury.
If you're ride has no flat spots or sweet spots, and you got the "go juice" all the way up to red line, lucky you.
For everyone else, post your props or flops here. Since I'm sure that we all would like to know how you got rid of any flat spots or got to their sweet spots faster, please describe what you did.
My A32 I30 has a slushbox. It launches like a slingshot when I power brake it at 1,500 RPM, but when it gets to 2k, the engine sort of goes out to lunch with the tranny and the car seems to lag along like a cheapo turbo.
It gets back to business right at 3k and keeps on trucking until it hits the spot where 00VI-equipped VQ's are still doing the Energizer Bunny thing.
I know that the power-braked RPM's might seem a bit low for launch, but dialing in higher revs always lays down more rubber than Nevada's Chicken Ranch.
One of my mods did reduce the lag, but when I hit 40MPH, the car ran about as fast as a Dell desktop but not as far.
One thing that this mod taught me was what happens when you restrict the openings where air has to go, and what happens when you make it less restrictive.
Maybe the TB has TB and like can't breathe in enough cool air? When I punch it, the car revs high way before the tranny wakes up and upshifts, resulting in missing that little break in traffic where you tried to drop on in.
I wonder if ECU controllers reduce or eliminate these flat spots on 95-96 A32's (like Jet and JWT)?
I wonder if they make them for 97-98's?
Any way, speak up and speak out. How much power do you want and how quickly do you want it? Do you notice any lags that bug you? Feel free to speak freely.
02-16-2008, 06:45 PM
#2
http://forums.maxima.org/forumdisplay.php?f=33
There's your good spots, flat spots, and whatever else.
There's your good spots, flat spots, and whatever else.
02-16-2008, 07:29 PM
#5
I like to hit right around 4,000 - 4,300 rpms .... if I am getting on it or pulling out in traffic, but I shift around 3k or so for mpg purposes. I don't feel that I get much pull after say 4,500 or so revs ... I love the sound, but as for torque, not so much after that. IMHO, it has to do with the intake manifold ... an 00vi or MEVI will kill a stock 3.0 VQ intake.
just my .02 worth ...
just my .02 worth ...
02-16-2008, 11:26 PM
#6
Senior Member
Join Date: Nov 2006
Posts: 2,391
I have a stock VQ30DE, i love the low end, pulls me out of tight spots, quick lane changes, and fast turns....i like doing this:when im cruising where ever instead of hitting the gas for the tranny to up shift (auto) i gently give it some gas, and from 1200 rpm, alll the way to 2000 or so when the tranny shifts, it has enough power do pull me ahead, up hills, out of traffic, doesnt matter, just keeps puling. Mind you im not on it like a maniac, just holding it down giving it a steady flow of gasoline....i love the low end growl too, you can hear it even with the stock box, it just goes deep like the sleeping monster the VQ is
When i do hit it, i notice the best output from 3000 to 4500 rpm, At 4500 the car just pulls, i mean it pushes me back and lets me know its going... but above that its like it revs to redline, but not much go, so yeah i guess the stock intake limits me there, but i dont need to rev it that high, dont need speeding tickets and dont need to rip my tranny in half...
When i do hit it, i notice the best output from 3000 to 4500 rpm, At 4500 the car just pulls, i mean it pushes me back and lets me know its going... but above that its like it revs to redline, but not much go, so yeah i guess the stock intake limits me there, but i dont need to rev it that high, dont need speeding tickets and dont need to rip my tranny in half...
02-17-2008, 09:46 AM
#9
Supporting Maxima.org Member
iTrader: (29)
Join Date: Oct 2005
Location: Middleboro/Carver, Ma
Posts: 4,572
I'll go back in time to when I had a 3.0 w/5mt, flywheel, y-pipe, and an intake (which now-a-days I would toss in the trash can)
3250 is where it would turn into a beast.
3250 is where it would turn into a beast.
holy similies and metaphors!
3900 is way to early
02-17-2008, 06:09 PM
#14
Not really. It is electric, but it is definitely not an E-RAM. I've just used it to test out some ideas I had about ways to eliminate the 2k to 3k lag. Basically, I learned that with a major increase in air flow, I can remove it.
What it does do (for about $25), is to remove nearly all of the 12" H20 total pressure drop that I had measured with a manometer, using a fully stock, air intake followed by using the blower setup hooked to my modded intake.
I'm using a 4" axial blower fan with a protective grille on it rated at 250CFM. It's attached to a three-way PVC tap. The tap has three openings: two are the front and back of a straight through pipe with a side pipe tapped into the the middle of it. This side opening is a large, curved pipe that receives air flow from the blower fan attached to it. and routes it up and out of the back end of the straight pipe and into the lower half of the air box
This arrangement (with the blower far away from the main air flow) is much safer than putting a blower fan directly inline with the airflow going to the filter -- which the E-RAM does. With its added grill, there is very little chance of anything breaking up and getting into the air box, if I were to use it permanently -- which is not exactly what I planned on doing.
It's just way too noisy to have it running constantly. If I did use it permanently, I'd hook it to a WOT switch. The blower only draws about 6 AMPS, so there would be no problem in keep it going.
What I want to do is find another means of reducing the negative pressure in the intake.
Has anyone ever measured, or know of someone who measured, the amount of pressure drop (or boost) that a true CAI can produce when compared to a stock box?
What it does do (for about $25), is to remove nearly all of the 12" H20 total pressure drop that I had measured with a manometer, using a fully stock, air intake followed by using the blower setup hooked to my modded intake.
I'm using a 4" axial blower fan with a protective grille on it rated at 250CFM. It's attached to a three-way PVC tap. The tap has three openings: two are the front and back of a straight through pipe with a side pipe tapped into the the middle of it. This side opening is a large, curved pipe that receives air flow from the blower fan attached to it. and routes it up and out of the back end of the straight pipe and into the lower half of the air box
This arrangement (with the blower far away from the main air flow) is much safer than putting a blower fan directly inline with the airflow going to the filter -- which the E-RAM does. With its added grill, there is very little chance of anything breaking up and getting into the air box, if I were to use it permanently -- which is not exactly what I planned on doing.
It's just way too noisy to have it running constantly. If I did use it permanently, I'd hook it to a WOT switch. The blower only draws about 6 AMPS, so there would be no problem in keep it going.
What I want to do is find another means of reducing the negative pressure in the intake.
Has anyone ever measured, or know of someone who measured, the amount of pressure drop (or boost) that a true CAI can produce when compared to a stock box?
Last edited by dr-rjp; 02-17-2008 at 06:15 PM.
02-17-2008, 08:32 PM
#16
Not really. It is electric, but it is definitely not an E-RAM. I've just used it to test out some ideas I had about ways to eliminate the 2k to 3k lag. Basically, I learned that with a major increase in air flow, I can remove it.
What it does do (for about $25), is to remove nearly all of the 12" H20 total pressure drop that I had measured with a manometer, using a fully stock, air intake followed by using the blower setup hooked to my modded intake.
I'm using a 4" axial blower fan with a protective grille on it rated at 250CFM. It's attached to a three-way PVC tap. The tap has three openings: two are the front and back of a straight through pipe with a side pipe tapped into the the middle of it. This side opening is a large, curved pipe that receives air flow from the blower fan attached to it. and routes it up and out of the back end of the straight pipe and into the lower half of the air box
This arrangement (with the blower far away from the main air flow) is much safer than putting a blower fan directly inline with the airflow going to the filter -- which the E-RAM does. With its added grill, there is very little chance of anything breaking up and getting into the air box, if I were to use it permanently -- which is not exactly what I planned on doing.
It's just way too noisy to have it running constantly. If I did use it permanently, I'd hook it to a WOT switch. The blower only draws about 6 AMPS, so there would be no problem in keep it going.
What I want to do is find another means of reducing the negative pressure in the intake.
Has anyone ever measured, or know of someone who measured, the amount of pressure drop (or boost) that a true CAI can produce when compared to a stock box?
What it does do (for about $25), is to remove nearly all of the 12" H20 total pressure drop that I had measured with a manometer, using a fully stock, air intake followed by using the blower setup hooked to my modded intake.
I'm using a 4" axial blower fan with a protective grille on it rated at 250CFM. It's attached to a three-way PVC tap. The tap has three openings: two are the front and back of a straight through pipe with a side pipe tapped into the the middle of it. This side opening is a large, curved pipe that receives air flow from the blower fan attached to it. and routes it up and out of the back end of the straight pipe and into the lower half of the air box
This arrangement (with the blower far away from the main air flow) is much safer than putting a blower fan directly inline with the airflow going to the filter -- which the E-RAM does. With its added grill, there is very little chance of anything breaking up and getting into the air box, if I were to use it permanently -- which is not exactly what I planned on doing.
It's just way too noisy to have it running constantly. If I did use it permanently, I'd hook it to a WOT switch. The blower only draws about 6 AMPS, so there would be no problem in keep it going.
What I want to do is find another means of reducing the negative pressure in the intake.
Has anyone ever measured, or know of someone who measured, the amount of pressure drop (or boost) that a true CAI can produce when compared to a stock box?
I WANT TO SEE PICS!
02-17-2008, 08:43 PM
#17
02-19-2008, 05:36 PM
#20
That's not it at all.
I left that mod in the dirt a long time ago.
02-19-2008, 06:21 PM
#21
I ditched the computer fan idea a long time ago, mainly because there was no way to get around the major obstacle it presented at 40mph and up. A lot of engine noise, but like treading water.
This other mod is totally different, and I will post pics in response to the query above. I solved the obstacle problem by having a three-way pipe where the straight portion of the pipe runs directly from the scoop to the air box while the blower fan (rated at 250CFM vs. the 107CFM of that litle fan) branches into it at the middle and at a sharp angle so that the air goes only one way -- towards the air box.
By accident, I made a minor, but significant, discovery that led me to conclude that my engine was literally starving for air thanks to the restrictive stock intake.
I was on the interstate, and I pulled off at a rest stop to refill my window washer.
When I got back onto the highway, I punched it so that I could pull ahead of a fast approaching semi. Well, the sudden blast of acceleration actually hurt my neck in the process.
It was then that I realized I had not fully closed the hood.
That is what led me to find another way to get extra air to the box on the cheap since I barely earn enough to keep food on the table, let alone spring for a true, quality CAI.
The current blower fan thing works, but its too noisy to have it running all the time. I would have to hook it up to a WOT switch, or maybe wrap it in some sound deadening material.
It is also not exactly a tight fit yet because the original stock intake is not in a straight line: it veers to the right after it drops down from the scoop in order to match up properly to the air box.
It's like Nissan treated the intake as an after-thought.
Thread
Thread Starter
Forum
Replies
Last Post
kjlouis
4th Generation Maxima (1995-1999)
12
10-03-2015 05:29 AM
zzznightmarezz
Maximas for Sale / Wanted
0
09-21-2015 06:32 PM