ATTN: Superchips distributor
Thread Starter
|
Senior Member
Joined: Mar 2000
Posts: 1,827
Likes: 0
From: FL
ATTN: Superchips distributor
i have a question for you. i have an 89 f-150 with a fairly stock speed density 302 and a 5 speed manual tranny. i was playing around with the idea of switching to mass air, but ive had plenty of people tell me im better off sticking to SD and a custom tune. im having the engine rebuilt soon and i am going to be adding some performance parts to the engine while im rebuilding it (heads, intake, cam...), could you make me a custom chip so my speed density won't have any problems, or will i need a custom tune? i know of a few people running setups like this on speed density computers with stock tune, but im guessing that if they had a custom tune done they should be able to pick up even more power. thanks for the help...
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi Donate54,
Well, you've probably heard this a million times, I wouldn't want to use a speed-density system with any camshaft change in these vehicles. Some of the best factory hot-rods (years ago) were speed density systems, and ran fine in stock trim and with certain types of modifications, but in a street driven vehicle you are so much better off with the MAF-based system, it's far more forgiving and flexible of the kinds of engine changes you are making.
Converting to MAF is *never* done for any immediate raw power gain, as that usually won't happen, which is the primary reason some people don't want to do it; they don't want to spend money that doesn't directly increase power, and that is the wrong way to look at that kind of change. It's not done for immediate power at all, it's done so your system is far more tolerant and forgiving of certain kinds of changes. Changes to valve timing events, duration, overlap, lobe centerline, etc. and cylinder head changes as well as other types of modifications. Speed density uses a MAP (manifold absolute pressure) sensor, so engine vacuum is basically the load signal. That's fine stock, and can work well in some turbo-motor applications, but when you do any significant camshart changes, etc., it raises it's head many times.
Can we do a custom speed density Superchip? In many cases that can be done, heck, that's all we had prior to MAF systems. Whether we are willing to get involved in that kind of project or not depends on just how much work is going to have to be done, which depends on things like how radical the cam is, other mods, etc. I'd want to see the cam card (or a copy) for the new cam and go over everything else in thorough detail before deciding if this is something we want to get involved in.
If you'd like to give us a call, we can go over this in more detail with you and get you a real answer like you need, ok?
Thanks!
Well, you've probably heard this a million times, I wouldn't want to use a speed-density system with any camshaft change in these vehicles. Some of the best factory hot-rods (years ago) were speed density systems, and ran fine in stock trim and with certain types of modifications, but in a street driven vehicle you are so much better off with the MAF-based system, it's far more forgiving and flexible of the kinds of engine changes you are making.
Converting to MAF is *never* done for any immediate raw power gain, as that usually won't happen, which is the primary reason some people don't want to do it; they don't want to spend money that doesn't directly increase power, and that is the wrong way to look at that kind of change. It's not done for immediate power at all, it's done so your system is far more tolerant and forgiving of certain kinds of changes. Changes to valve timing events, duration, overlap, lobe centerline, etc. and cylinder head changes as well as other types of modifications. Speed density uses a MAP (manifold absolute pressure) sensor, so engine vacuum is basically the load signal. That's fine stock, and can work well in some turbo-motor applications, but when you do any significant camshart changes, etc., it raises it's head many times.
Can we do a custom speed density Superchip? In many cases that can be done, heck, that's all we had prior to MAF systems. Whether we are willing to get involved in that kind of project or not depends on just how much work is going to have to be done, which depends on things like how radical the cam is, other mods, etc. I'd want to see the cam card (or a copy) for the new cam and go over everything else in thorough detail before deciding if this is something we want to get involved in.
If you'd like to give us a call, we can go over this in more detail with you and get you a real answer like you need, ok?
Thanks!