A K&N flat panel filter from six years ago?
Would probably have better luck PMing him. And a suggestion, make a donation after buying it
Would probably have better luck PMing him. And a suggestion, make a donation after buying it
wondering about cheap ways to increase power
- Thread starter 91 SHO Black
- Start date
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DeepPower
Searchng4Truth
Coming late to this thread, I've done all the above EXCEPT the Y-pipe. My priorities have changed on my '89 SHO. While I'm thrilled with the performance, I now have a daily commute that is is 45 minutes & 40 miles each way, so I'm putting 400 miles per week on the car. This is also a lifestyle change as I spend about 8 hours a week commuting. Looking to get a second car that's an automatic, maybe a 2003 BMW 530i.
I plan on moving closer to work, but before that I'd like to reduce my trips to the gas station. Would a Y-pipe improve my gas mileage (I'm talking to you, SHOSource)?
We don't have number but since it is removing an actual restriction in the system it should help.
DeepPower
Searchng4Truth
What about the back-pressure issue? That's why I'm reluctant to remove my catalytic converter.
luigisho
SHO Member
If there are any savings in mileage, which no one has proven, I wonder how long it would take to offset the cost of the parts (and labor cost if not done yourself). I don't think improved mileage is a good reason to install a catless ypipe.
DeepPower
Searchng4Truth
Well, to be clear, my priorities are different than saving money due to mpg. I'm looking to reduce my trips to the gas station, like from 2x a week to maybe 3x every two weeks.
There is a very sharp bend in the cats which causes the excess back pressure. This is why installing a y-pipe on an MTX results in gains but an ATX which has a better flowing y-pipe does not have the same gains.
DeepPower
Searchng4Truth
I thought that reducing the back pressure reduces power at low RPMs:
http://www.shoforum.com/index.php?threads/someone-explain-to-me.94699/#post-979597
http://www.shoforum.com/index.php?threads/someone-explain-to-me.94699/#post-979655
More in that same thread.
sperold
Last to Know
I have no dog in this fight, but do not underestimate the value of the equal length Y-Pipe by ShoSource. I bought and installed the catted model and got better mileage and performance. the cat free model is quite a bit cheaper, but the e-test issue, both now and in the future, dictated the cats.
At the time, I had a 600 mile weekly commute. So don't bother getting another car, as mine had well over 200 k miles, and it did it no disservice.
The gains are small in both categories, but they are there and you notice the mileage when you are filling up which seems like all the time. I got to the point where I carried gas in the trunk as the trip was one that did not have any stations for most of the trip.
The hidden beauty of this system is it can be installed by one person in your driveway. It comes in segments that are easy to position, and you don't need a bunch of jack-stands to hold up that one piece system you get from other suppliers. And no more coaxing one side to fit on the cast iron manifolds after you have set one side in place.
If you are looking for a one or two year payback in saved mileage, you are not going to get it, as the system is a premium stainless unit and is comparatively costly.
At the time, I had a 600 mile weekly commute. So don't bother getting another car, as mine had well over 200 k miles, and it did it no disservice.
The gains are small in both categories, but they are there and you notice the mileage when you are filling up which seems like all the time. I got to the point where I carried gas in the trunk as the trip was one that did not have any stations for most of the trip.
The hidden beauty of this system is it can be installed by one person in your driveway. It comes in segments that are easy to position, and you don't need a bunch of jack-stands to hold up that one piece system you get from other suppliers. And no more coaxing one side to fit on the cast iron manifolds after you have set one side in place.
If you are looking for a one or two year payback in saved mileage, you are not going to get it, as the system is a premium stainless unit and is comparatively costly.
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DeepPower
Searchng4Truth
Thanks, you clearly understand my situation! I'm not directly looking to save money over time by improving gas mileage, like you I need to improve how far I can go on a tank.
Although my '89 SHO does not need to be emissions tested in Texas, by your experience the catted SS Y-pipe will benefit me. Any change in engine noise, or low-end performance?
Still curious if anyone has experience on if the catless SS Y-pipe will affect low end.
luigisho
SHO Member
I think it does a bit, but not worth worrying about.
Cat less y pipe will be noticeably louder and have more vibration. In my younger years that was no big deal, but now, especially with a longer commute-- I would have to think hard about if it was worth it. Getting older though...
Cat less y pipe will be noticeably louder and have more vibration. In my younger years that was no big deal, but now, especially with a longer commute-- I would have to think hard about if it was worth it. Getting older though...
DeepPower
Searchng4Truth
Hmmm... doesn't sound like something I can live with on a long daily commute.
How about a catless Y-pipe with some sort of muffler/restrictor instead of the cat?
sperold
Last to Know
I toyed with the idea of buying the catless system and adding converters later, but decided that by the time I did that, I would be behind financially.
There is no downside in having the cats, and the system offers an improvement in low end torque, and all through the band.
There is a change in sound at the low end, but it is an improvement, as it is reminiscent of having headers in the old days; sort of a metallic pulsing. More of an idle thing. I think that during the cool down phase when it is shut down, you hear some almost crackling as the stainless piping cools, but that was more prevalent when the system was new.
The pipe is very close to the drain plug, and at first it looks like it is not going to work. But it does.
With these cars, intuition does not serve you well. In the old days, SHOShop built a header system and when installed, the engine developed less horsepower on the dyno. So getting rid of the cats altogether puts you in that strange zone where things don't behave regularly. It is best to simply follow the leader and use something that is proven to work.
There is no downside in having the cats, and the system offers an improvement in low end torque, and all through the band.
There is a change in sound at the low end, but it is an improvement, as it is reminiscent of having headers in the old days; sort of a metallic pulsing. More of an idle thing. I think that during the cool down phase when it is shut down, you hear some almost crackling as the stainless piping cools, but that was more prevalent when the system was new.
The pipe is very close to the drain plug, and at first it looks like it is not going to work. But it does.
With these cars, intuition does not serve you well. In the old days, SHOShop built a header system and when installed, the engine developed less horsepower on the dyno. So getting rid of the cats altogether puts you in that strange zone where things don't behave regularly. It is best to simply follow the leader and use something that is proven to work.
luigisho
SHO Member
You can install anything inline you can fit. I would stay stock, unless I was trying to push serious horsepower and wanted more flow or the current y-pipe needed replacment. Other than that, just stay stock(ish) and enjoy it for what it is for the most part.
DeepPower
Searchng4Truth
That's what I'm thinking. Although I do have a cat that has 300K+ miles on it so it may be a bit too restrictive. I'm thinking now I'd like to replace that cat with some sort of restriction that provides appropriate back pressure. Has anyone done this?
luigisho
SHO Member
I think I remember someone putting in something like a glasspack straight muffler inline but that was a really long time ago. I forget if it was even these cars or the v8 SHO. After all the years things kind of blend together. Might have even put it on the forward end of the catback. I forget. Size and geometry is the issue with stuff like that
Any muffler might not last long as the system is much hotter being so close to the engine. Mufflers or resonators are meant for being further down the line.
DeepPower
Searchng4Truth
Ah, good point.
I've emailed Dynomax about replacing my cat with a glasspack or something similar, mentioning that I'm concerned about losing backpressure/velocity of exhaust gases. I'll post what they say.
Garichette
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