Hey Mike, another reburn for gears question.
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi XLT-Sport,
When you put in "shorter" gears (meaning numerically higher), you will turn more rpms for any given speed in any gear, but that will *not* affect your idle speed at all.
What the engine turns in Neutral or Park or with the clutch pushed in on a manual will not change due to changing gear ratios, as the motor is not connected to the differential at that point.
For example if you change 3.55 gears to 4.10 gears, that is a 15.49% change, so you will turn 15.49% more rpms for any given speed in any gear.
Let's say your cruising speed is 70 mph, and you're turning 2000 rpm at 70 with the 3.55's. With the 4.10's at the same speed of 70 mph, you would turn 15.49% more rpms (4.10-3.55/3.55=15.49%), so you simply take 2000 rpm X 115.49 (100 + the 15.49% difference = 115.49) and so now you turn 2310 rpms (in round numbers) at 70 mph with 4.10's, in this example.
When you put in "shorter" gears (meaning numerically higher), you will turn more rpms for any given speed in any gear, but that will *not* affect your idle speed at all.
What the engine turns in Neutral or Park or with the clutch pushed in on a manual will not change due to changing gear ratios, as the motor is not connected to the differential at that point.
For example if you change 3.55 gears to 4.10 gears, that is a 15.49% change, so you will turn 15.49% more rpms for any given speed in any gear.
Let's say your cruising speed is 70 mph, and you're turning 2000 rpm at 70 with the 3.55's. With the 4.10's at the same speed of 70 mph, you would turn 15.49% more rpms (4.10-3.55/3.55=15.49%), so you simply take 2000 rpm X 115.49 (100 + the 15.49% difference = 115.49) and so now you turn 2310 rpms (in round numbers) at 70 mph with 4.10's, in this example.
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi FLea,
Yes, I'd say so, on a 4X4 that's a great price, assuming we're talking about using top-shelf quality on the gears, etc. being used. Make sure the shop you use for the gears guarantees no undue noise (typically gear "whine") as a result of this change, & good luck!
Yes, I'd say so, on a 4X4 that's a great price, assuming we're talking about using top-shelf quality on the gears, etc. being used. Make sure the shop you use for the gears guarantees no undue noise (typically gear "whine") as a result of this change, & good luck!
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi Screamer,
It's easy to tell if we have read your email by virtue of whether or not you have received our response. If you haven't received a response yet, then we haven't read that email yet.
Just so you'll know for future reference, we generally do email once a day during the week, during our normal hours of operation. Our normal hours of operation are Monday thru Friday from 10 am to 7 pm Eastern time. Though we usually end up working 7 days a week, we don't do email 7 days a week.
Here lately, you've been sending us numerous emails as well as posts here every day, and you've been getting rapid responses from us to both. Usually we can't respond that quickly, but I had a bit of extra free time over the past 2 days (which happens almost never), and so we were able to get back to you quicker than normal.
Anytime someone wants to communicate with us quickly, the way to do that is to call us, as it usually takes a couple of days to get an email response due to our heavy email load.
Just trying to give you an idea of how best to commuicate with us, how long it usually takes to commuicate with us in email, etc.
It's easy to tell if we have read your email by virtue of whether or not you have received our response. If you haven't received a response yet, then we haven't read that email yet.
Just so you'll know for future reference, we generally do email once a day during the week, during our normal hours of operation. Our normal hours of operation are Monday thru Friday from 10 am to 7 pm Eastern time. Though we usually end up working 7 days a week, we don't do email 7 days a week.
Here lately, you've been sending us numerous emails as well as posts here every day, and you've been getting rapid responses from us to both. Usually we can't respond that quickly, but I had a bit of extra free time over the past 2 days (which happens almost never), and so we were able to get back to you quicker than normal.
Anytime someone wants to communicate with us quickly, the way to do that is to call us, as it usually takes a couple of days to get an email response due to our heavy email load.
Just trying to give you an idea of how best to commuicate with us, how long it usually takes to commuicate with us in email, etc.
Thread Starter
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Senior Member
Joined: Jul 2000
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From: Houston, by way of every major city in America.
Well, I just sent one to you right before I got this e-mail notification
. It's still current as to it's general content. Thanks for taking the time to answer the e-mails.,,,,98
. It's still current as to it's general content. Thanks for taking the time to answer the e-mails.,,,,98
,,,,,98
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi Screamer,
I went ahead and read thru your emails & your posts here, and then called you to discuss your concerns. I enjoyed being able to speak to you again at length, it's been awhile since we talked for any length of time. Glad to hear you're goinf to be getting more performance from that truck!
At any rate, we'll go ahead and make the changes we discussed to your program, taking into consideration the additional modifications you're going to be doing as well. As soon as we have that finished, we'll give you a call to let you know & then you can shoot your Superchip in to us for the new programming.
It's pretty rare to see H-pipes over the past few years in true dual exhaust systems, for some years now we see almost exclusively X-pipes used, which have more of an effect on A/F ratios. I'm glad we had a chance to go over that in detail over the phone, so we could describe when & how we get to the point where it's time to actually compensate for certain modifications used in combination with other modifications, when it can be beneficial to gain a bit more power versus when it's actually *required*, etc.
We'll also be taking a look at what we discussed with regard to the rough downshift you've been experiencing since the changes you made to your MAF. It would help us if you could write out a note for us, describing the circumstances under which this happens. If it' something that happens under any heavy-throttle downshift, or if it has to be a full-throttle downshift, if it only happens on the 4-3, or on the 3-2, etc., all the details you can think of, that will help us to look in those specific areas. You can either email that to us, or you can FAX that over to us at 540-862-9485 anytime, 24 hrs. a day.
Since you've had the Superchip for a couple of years with no problem, then this problem just started at about the same time as the changes you made to your MAF, my suspicion is that we're probably going to find that this is related to the MAF changes, but of course please do check the motor mounts and the transmission mount as well. As we discussed, because the MAF is the powertrain's primary load signal, it affects not only engine tuning, but also has a large effect on overall transmission shift characteristics as well, as they are load based. If that is the case, then it's time to go back to the original MAF housing & just transfer over the electronics, as you were talking about. We'll see how it turns out after we look at all that.
As we also discussed, once you have the electric fans and/or the underdrive pulleys installed, it's time to upgrade the in-tank fuel pump to keep up with the power levels you'll be at, to make sure you don't go lean at higher rpms in the higher gears (especially 3rd & 4th). It is at that point that you'll be about maxed out on your fuel injectors as well, so if you go on to do more modifications *after* the electric fans & underdrive pulleys, you'll need to go to larger fuel injectors too, which will require custom tuning.
We figured that right now, you're at somewhere between the 260-275 HP level depending on altitude, fuel quality & engine health (especially the condition of the ignition system). Your 19# stock injectors can support 304 HP @ 80% duty cycle assuming a BSFC of 0.50, a bit more if you push them to higher duty cycles, but we don't ever like to see anything beyond 90% and ideally not above 85% duty cycle at top speed in 4th gear.
You will not need to have any changes made to your Superchip programming for the upgraded fuel pump, but if you do go on to do even more modifications after doing the electric fan conversion & underdrive pulleys, *then* you'll need to upgrade the injectors & that will require more custom tuning in the powertrain program.
One last thing to mention in general, as we didn't talk about this over the phone, is to make sure that the ignition system is up to snuff, meaning good quality aftermarket spark plug wires & coil packs should be used when you replace those components, along with good spark plugs. If you are still running the original stock plug wires & coil packs, they are due for replacement, and you can get some nice additional power gains from that on those non-cop 4.6 motors like yours. Good ignition components like the Accel or MSD units aren't any more expensive than the factory parts, and usually they're cheaper, we offer package deals on those upgrades and a lot of 4.6 owners love our ignition upgrades. If the ignition system isn't up to snuff, that too can contribute to a lean condition from not burning enough of the Air/Fuel mixture, even though you don't
get a dead miss. If you have recently replaced those components, even if it is with factory parts, then I wouldn't replace them right now again, I'd wait until you have about 40K miles on the replacement plug wires & coil packs.
What we should do is to talk again at some point, probably when we call you to let you know the new program is ready would be a good time, and map out exactly what needs to be done in exactly what order & when, so that we do not have any misunderstandings or mistakes as you go further and further with your modifications, we're happy to help you at each stage along the way.
Good talking with you again & be safe out there on the road on all those trips!
I went ahead and read thru your emails & your posts here, and then called you to discuss your concerns. I enjoyed being able to speak to you again at length, it's been awhile since we talked for any length of time. Glad to hear you're goinf to be getting more performance from that truck!
At any rate, we'll go ahead and make the changes we discussed to your program, taking into consideration the additional modifications you're going to be doing as well. As soon as we have that finished, we'll give you a call to let you know & then you can shoot your Superchip in to us for the new programming.
It's pretty rare to see H-pipes over the past few years in true dual exhaust systems, for some years now we see almost exclusively X-pipes used, which have more of an effect on A/F ratios. I'm glad we had a chance to go over that in detail over the phone, so we could describe when & how we get to the point where it's time to actually compensate for certain modifications used in combination with other modifications, when it can be beneficial to gain a bit more power versus when it's actually *required*, etc.
We'll also be taking a look at what we discussed with regard to the rough downshift you've been experiencing since the changes you made to your MAF. It would help us if you could write out a note for us, describing the circumstances under which this happens. If it' something that happens under any heavy-throttle downshift, or if it has to be a full-throttle downshift, if it only happens on the 4-3, or on the 3-2, etc., all the details you can think of, that will help us to look in those specific areas. You can either email that to us, or you can FAX that over to us at 540-862-9485 anytime, 24 hrs. a day.
Since you've had the Superchip for a couple of years with no problem, then this problem just started at about the same time as the changes you made to your MAF, my suspicion is that we're probably going to find that this is related to the MAF changes, but of course please do check the motor mounts and the transmission mount as well. As we discussed, because the MAF is the powertrain's primary load signal, it affects not only engine tuning, but also has a large effect on overall transmission shift characteristics as well, as they are load based. If that is the case, then it's time to go back to the original MAF housing & just transfer over the electronics, as you were talking about. We'll see how it turns out after we look at all that.
As we also discussed, once you have the electric fans and/or the underdrive pulleys installed, it's time to upgrade the in-tank fuel pump to keep up with the power levels you'll be at, to make sure you don't go lean at higher rpms in the higher gears (especially 3rd & 4th). It is at that point that you'll be about maxed out on your fuel injectors as well, so if you go on to do more modifications *after* the electric fans & underdrive pulleys, you'll need to go to larger fuel injectors too, which will require custom tuning.
We figured that right now, you're at somewhere between the 260-275 HP level depending on altitude, fuel quality & engine health (especially the condition of the ignition system). Your 19# stock injectors can support 304 HP @ 80% duty cycle assuming a BSFC of 0.50, a bit more if you push them to higher duty cycles, but we don't ever like to see anything beyond 90% and ideally not above 85% duty cycle at top speed in 4th gear.
You will not need to have any changes made to your Superchip programming for the upgraded fuel pump, but if you do go on to do even more modifications after doing the electric fan conversion & underdrive pulleys, *then* you'll need to upgrade the injectors & that will require more custom tuning in the powertrain program.
One last thing to mention in general, as we didn't talk about this over the phone, is to make sure that the ignition system is up to snuff, meaning good quality aftermarket spark plug wires & coil packs should be used when you replace those components, along with good spark plugs. If you are still running the original stock plug wires & coil packs, they are due for replacement, and you can get some nice additional power gains from that on those non-cop 4.6 motors like yours. Good ignition components like the Accel or MSD units aren't any more expensive than the factory parts, and usually they're cheaper, we offer package deals on those upgrades and a lot of 4.6 owners love our ignition upgrades. If the ignition system isn't up to snuff, that too can contribute to a lean condition from not burning enough of the Air/Fuel mixture, even though you don't
get a dead miss. If you have recently replaced those components, even if it is with factory parts, then I wouldn't replace them right now again, I'd wait until you have about 40K miles on the replacement plug wires & coil packs.
What we should do is to talk again at some point, probably when we call you to let you know the new program is ready would be a good time, and map out exactly what needs to be done in exactly what order & when, so that we do not have any misunderstandings or mistakes as you go further and further with your modifications, we're happy to help you at each stage along the way.
Good talking with you again & be safe out there on the road on all those trips!