Why Doesn't Any Company Make A Header For The 5SFE Options

[CyberCT]

I have been browsing this forum for quite some time and have noticed that NO COMPANY make a header for the 2.2l 5sfe. SSAutochrome was about to but then people backed out (and yes, I have seen claims of their poor quality with some products. Fortunately this header wasn't bad. There was one or two instances where they did crack or break though in the MR2 community, and that's about it).

I had three MK II MR2s with the 5sfe. I also had the SSAC header on one of them. Let me tell you the performance improvement was noticable right away. It was almost like night and day. More pull and it ran quicker through the gears.

When I had to put the stock exhaust manifold back on for inspection, the car ran much slower, easily noticable.

Now, the NA MR2 weighs in at @ 2650 lbs. The 94-99 Celica GT hardtop weighs in at @ 2450 lbs, correct? A good header would probably make it quicker in a line than the MR2, which felt good in a line.

Is there atleast a header in the works from a reputable aftermarket company?


I'm probably going to be buying a 6th gen celica in the near future as my new daily driver. Is there any place where I can see the yearly updates they did to the celica to fix problems from the previous year? Like for example, in 93, the MR2 fixed some electrical problems or quirks, and upgraded the suspension and other things. Is there a list like this for the 6th gen celicas?

[Digndoug]

its not really worth it.. its a very low end design engine.. I think the only mod worth doing would be a turbo and to run it under 7psi.

[CyberCT]

But the 1.8l ST engine would be better, considering there is a header available for it? I'm not looking for a street king. Just some extra punch, like what I got with my MR2. I've experienced the potential and I like it.

[Galcobar]

If you'd been browsing you'd know the 5SFE header is available from Hotshot and Genie -- or you could use a 4-2-1 from a 3SGE.

[MonsterBOX]

r u sure the mr2 is heavier than a gt celica? that doesnt sound right maybe though

[Galcobar]

Sounds odd to me as well...two-seater versus four?

[CyberCT]

94-99 Celica GT 2 Door Hatchback: 2415lbs
http://auto.consumerguide.com/Auto/Used/re...carreviewspecs/

91-95 MR2 Nonturbo: 2657lbs
http://auto.consumerguide.com/Auto/Used/re...carreviewspecs/


91-95 MR2 Turbo Curb weight is over 2800 lbs. More info can be found on the MR2OC Message board, and the MR2's weight is verified there.
http://www.mr2oc.com/showthread.php?t=1015...ght=curb+weight


Now, about the header. I can only find a header for the 90-93 Celica GT 5SFE, and for the 94-99 ST. Neither Hotshot nor Genie make a header for 94-99 Celica GTs according to their websites. Can I used a header from the previous generation Celica GT? Will it bolt right on? I don't want to get into fabing one up, just a direct bolt on like the SSAC Header on my 91 MR2 NA. Same with a good cold air intake by a performance company, which also can't be found. I saw the do-it-yourself CAI on this site for the Celica GT, but I don't want to cut my fuse box or anything like that. Another direct bolt on.

[Kwanza26]

The Celica GTs weigh around 2600 pounds depending on options and such. Only the Celica ST coupe weighs less than 2500 pounds. A bare bones hardtop MR2 (mine) weighs a little bit over 2600 pounds, T-tops and sunroof ones are even heavier. They're about the same. The reason the MR2 is heavy, front and rear firewalls, reinforced front and rear chassis... Oh... the Celica GT is not as quick as an n/a MR2...

As for modifications, IMO, the 7AFE in the Celica ST is a better platform for n/a modification. The problem with the 5SFE is the way it was deisgned to make torque. The piston dwell and such is very poor for making top-end power, so adding on a header isn't gonna make a big difference. The 7AFE on the other hand can hold its own modified. Oh... and there's no reason the MR2 5SFE header won't work on the Celica. I'd imagine only some minor modifications are needed for it to work.

[Galcobar]

The Genie and Hotshot headers are not exact bolt-ons for the sixth-gen Celicas, that's true. However, the grand total work on them requires a custom front pipe (on the Genie) or mid-pipe (on the Hotshot) to mate them perfectly. It's a matter of millimetres.

As for the CAI, you only have to cut the fuse box if you put on a large intake. A two-inch diametre intake will fit without having to cut or relocate anything.

[CyberCT]

Wait, so a 7AFE puts out more power and tq with a header and CAI than a 5SFE with stock exhaust manifold and airbox? If this is so, I might go that route. But I want leather interior and it looks like only the GTs have that.

[Bigmeanbulldog55]

Wait, so a 7AFE puts out more power and tq with a header and CAI than a 5SFE with stock exhaust manifold and airbox?  If this is so, I might go that route.  But I want leather interior and it looks like only the GTs have that. 
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No. 7a is a better platform because it has more parts avalible. It is not a better engine. They are the same quality, it's just that the 7a was put in corrola's and prizums, so there's more cars with them, and more parts for them. If you want to have fun, go with a 4age swap into a gt or st. They seem to be cheaper, and probably easier to find than a 3s. But neither celica has any power or potential with the stock motors.

[Kwanza26]

Wait, so a 7AFE puts out more power and tq with a header and CAI than a 5SFE with stock exhaust manifold and airbox?  If this is so, I might go that route.  But I want leather interior and it looks like only the GTs have that. 
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I didn't say that... I said the 7AFE has better potential for n/a horsepower, while the 5SFE has better potential for more torque. Considering most modifications make more horsepower than torque (n/a mods), the 7AFE has a step up on the 5SFE. In boosted form, nothing will beat displacement... but in n/a trim, an engine's stroke ratio (most affected by displacement) is gonna take the cake.

[CyberCT]

I don't want to do any internal mods, only bolt on with CAI and Header. No turbo, no engine work, nothing more. That's why I looked at the 5SFE like with my MR2. The stock exhaust manifold is very restrictive and what a difference an aftermarket header made, with a CAI.

There's quite a bit available for the Integra GSR and I might do that instead. Or I could keep my bland daily driver and wait for a 93+ turbo or NA MR2 to become available in my area that is in good condition.

With a header and CAI, are there any dynos for the 7AFE and what it puts out.



This post has been edited by CyberCT: Jun 13, 2005 - 10:53 AM

[darksecret]

One of the main causes for the high torque rating is because the 5SFE has some pretty long intake runners, which in turn increase torque numbers, the restrictive head and long IR make for higher torque with lower horsepower, it's been proven time and again. If you could modify the current runners you would lower torque but increase the horsepower potential, or you could rebuild the motor with forged pistons and rods, give the head some mean work, get some high profile cams and boost it, you'll have a beast, but of course $$$. I have realized that the head is the most restrictive part of the entire engine and it's actually pretty beefy to be aluminum. The main reason nobody builds parts for the Celica is because it is a fairly rare car compared to a 240SX and Civic (not to mention when the car was popular the import scene was still small and most americans couldn't tell you what a WRC is), the 5SFE may not have a lot of potential as is, but it really isn't much to make it a beast, if we could get the aftermarket on our side. Also cars like the Corolla and Prizm, 5SFE had the Camry and MR2, I don't think that was the reason.

This post has been edited by darksecret: Jun 13, 2005 - 10:57 AM

[Kwanza26]

One of the main causes for the high torque rating is because the 5SFE has some pretty long intake runners, which in turn increase torque numbers, the restrictive head and long IR make for higher torque with lower horsepower, it's been proven time and again. If you could modify the current runners you would lower torque but increase the horsepower potential, or you could rebuild the motor with forged pistons and rods, give the head some mean work, get some high profile cams and boost it, you'll have a beast, but of course $$$. I have realized that the head is the most restrictive part of the entire engine and it's actually pretty beefy to be aluminum. The main reason nobody builds parts for the Celica is because it  is a fairly rare car compared to a 240SX and Civic (not to mention when the car was popular the import scene was still small and most americans couldn't tell you what a WRC is), the 5SFE may not have a lot of potential as is, but it really isn't much to make it a beast, if we could get the aftermarket on our side. Also cars like the Corolla and Prizm, 5SFE had the Camry and MR2, I don't think that was the reason.
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That is a reason... but that's not THE reason. The problem with the 5SFE making n/a power is the bottom-end. The rods are relatively short, considering it has a full 5mm taller stroke than the 3S, yet the rods' lengths are only about a mm difference (5S vs 3S)... High horsepower, small displacment engines typically have fairly long rods, keeping a good rod/stroke ratio and maintaining good piston dwell time, allowing better combustion, longer compression, and allows for faster revolutions with less internal stress (less piston movement). The 5SFE, with shorter rods, has less piston dwell, but allows for better intake and exhaust velocity at mild speeds... basically it can take larger gulps because the piston has to move more. No matter what you do to the head, the cams, the intake set-up, etc... the basic stroke design is gonna limit the way the engine makes torque. This is the MAJOR reason why I don't think an n/a 5SGE build is a very bright idea (refer to older posts). Little things such as intakes, headers, exhausts... increase efficiency only on a very small scale and are small-time mods for an n/a motor.

You gotta understand the basics of how one part of the engine affects the other if you really want to make n/a power. Even with headwork, bolt-ons, cams, the basic stuff just to open up the engine's potential, you gotta understand that the engine's geometry greatly affects how much potential power can be made. That's why you don't see a lot of n/a mods for the bigger 4 bangers, especially if they're not as popular. If you want bolt-on power... go turbo.

Check out Jim Snodgrass's (http://www.jimsnodgrass.com/dyno.htm) page to see what he did to his 5SFE and then see how much power he actually made. He has the highest whp out of all the n/a 5SFE's I've seen, but even then his powerband looks exactly the same as it did before. Goes to show it's not easy to change an engine's characteristics with bolt-on mods.

[darksecret]

Yeah I know how the ratios work, but last time I checked most large displacement engines were oversquare which means nothing, it's actually better for street use, undersquare revs higher due to the added stability of the longer rods and rod travel, but don't rule undersquare engines out, I remember when I first came to this forum and you told me I came to this looking like a domestic guy, well when you have half a friggin V8 sitting under your hood yeah it's easy to look at it that way. Unfortunatly that half is a crappy half, but you must remember that the block is very strong the crank is strong, and the head is beefy leaving plenty of room for upgrading, it actually doesn't help this car by having DOHC but who'll complain. In most cars you'll run into the domino effect you upgrade this and break that and that is one problem the 5SFE does face, weak internals and valvetrain. If everyone stop trying to make this motor hit 12,000 rpm and take it for what it is we might see a few better mods, oversquare engines never do well with long runners and the 5SFE is nearly 10 inches where the 7A is what 6".

This post has been edited by darksecret: Jun 13, 2005 - 6:37 PM

[CyberCT]

Ah yes but this is missing the whole point. BOLT ONs. A header and intake made a significant difference on my MR2. The MR2 is more rare than the 6th gen celica, so that's not the reason.


NO internal engine work, NO turbo, NO completely changing around the engine bay and many of it's parts. Just a header and intake. Plain and simple. I think the confusion here is everyone thinks "street beast" when modding. I just want a boost in power.

Nevertheless, I guess I'll just wait for a nice MR2 or GSR to show up around my area and buy that instead.

[darksecret]

A little boost, like seat of the pants boost? You're kind of SOL like I said out of the box the 5SFE sucks, when you start changing the dynamics of the motor is when it runs like it's suppose to. You confused me with that MR2 is more rare thing, I know it is, well the newer ones are anyways, but people don't look at the MR2 as being weak thanks to the turbo version surviving a little longer, if the same happened to the Celica it would have a few more parts also.

[Kwanza26]

Yeah I know how the ratios work, but last time I checked most large displacement engines were oversquare which means nothing, it's actually better for street use, undersquare revs higher due to the added stability of the longer rods and rod travel, but don't rule undersquare engines out, I remember when I first came to this forum and you told me I came to this looking like a domestic guy, well when you have half a friggin V8 sitting under your hood yeah it's easy to look at it that way. Unfortunatly that half is a crappy half, but you must remember that the block is very strong the crank is strong, and the head is beefy leaving plenty of room for upgrading, it actually doesn't help this car by having DOHC but who'll complain. In most cars you'll run into the domino effect you upgrade this and break that and that is one problem the 5SFE does face, weak internals and valvetrain. If everyone stop trying to make this motor hit 12,000 rpm and take it for what it is we might see a few better mods, oversquare engines never do well with long runners and the 5SFE is nearly 10 inches where the 7A is what 6".
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If that's your response... you missed the WHOLE point of my explaining rod/stroke ratios and piston dwell. Let me make it easy for you... the 5SFE is not a horsepower engine and even with headwork, cams, intake manifold, etc... That's just the way the engine is, regardless of mods, short of changing the rod/stroke ratio. It's a torque engine... but even in that trim, you can't squeeze additional torque out of the motor without opening it up, or adding forced induction. Notice I only mention small displacement engines (4 bangers more-or-less)? Look at ALL of the 5SFE dynos and just about every single time, the 5SFE makes much more torque than horsepower. You can go on about undersquared motors are more user friendly, which I agree... but this isn't the daily driver forum. This is engine performance... which means to squeeze power. When it comes to squeezing horsepower, the 7AFE has a better rod/stroke ratio for making n/a power.

As for undersquared motors... stroker motor. Nuff said. Like I said before... don't talk torque unless you're gonna have a sh!t load of it. 150 ft lbs or before 4500 rpms is nothing. 300-500 ft lbs... that's a bit better... but not out of an n/a "small displacement engine"...

Seriously now... if you want more power out of the 5SFE... turbo charge it. It's not gonna make great power with bolt-ons... unlike the 7AFE, which still has a chance.

[Kwanza26]

Ah yes but this is missing the whole point.  BOLT ONs.  A header and intake made a significant difference on my MR2.  The MR2 is more rare than the 6th gen celica, so that's not the reason.

NO internal engine work, NO turbo, NO completely changing around the engine bay and many of it's parts.  Just a header and intake.  Plain and simple.  I think the confusion here is everyone thinks "street beast" when modding.  I just want a boost in power.

Nevertheless, I guess I'll just wait for a nice MR2 or GSR to show up around my area and buy that instead.
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So do you just want a header, or do you want a car that you think is gonna be faster than an MR2 with the same engine? If you just want a header... buy an MR2 one and have an exhaust shop modify it to fit. If you want to be able to hang with 5SFE MR2's... well... you're not gonna. The MR2 is a bit quicker. My MR2 can throw down high 15 second 1/4 mile runs (stock) while the best I've seen out of lightly modded Celica GT's is low 16's...

Also... I don't think any of the Celica folks, aside from relative newbies, think "street beast". You're thinking a header is gonna make a whole lot of difference... we're just telling you it's not, and explaining why it's not... and then letting you know what WILL make a difference.

This post has been edited by Kwanza26: Jun 13, 2005 - 7:33 PM