Was not really looking at replacing the OEM cat with a straight pipe but Ivo triggered my interest as it does save weight :-* :-*
The pallet of products availeble is again quite wide; from 150 to 450 quid. The ´Malian´ being the cheapest.
https://www.kage-uk.com/product/toyota-mr2-spyder-1-8-performance-exhaust-downpipe-decat/
Cannot see it being as critical as the manifold so my appetite is gettig wetted. Easy fix and it ís 4 kilos or so less behind the rear axle. Also a lót less heat rising up from that heat sink cat.
Well not thát easy as I would need to repack the absorbtion end damper. That will need doing anyway.
So; any experiences; ány?
Quote from: Petrus on July 9, 2019, 11:41Was not really looking at replacing the OEM cat with a straight pipe but Ivo triggered my interest as it does save weight :-* :-*
The pallet of products availeble is again quite wide; from 150 to 450 quid. The ´Malian´ being the cheapest.
https://www.kage-uk.com/product/toyota-mr2-spyder-1-8-performance-exhaust-downpipe-decat/
Cannot see it being as critical as the manifold so my appetite is gettig wetted. Easy fix and it ís 4 kilos or so less behind the rear axle. Also a lót less heat rising up from that heat sink cat.
Well not thát easy as I would need to repack the absorbtion end damper. That will need doing anyway.
So; any experiences; ány?
:O thats quite low price, id just try it out. I have seen these guys offering a turbo kit with no turbo but this is something new.
I have the catted version of this downpipe.
Its a real pain because the gaskets leak on both ends. In order to stop the leaks I had to modify the downpipe on one end using a small tube so the donut gasket can work like the OEM arrangement.
On the header side it required me to make my own gasket using a special carbon material because the gasket they provide cant handle the heat and blows out cutting the gasket in half.
In addition to this I needed to use high temp thread locker to keep the nuts from backing out due to vibrations having them walk.
This downpipe is not bad as far as welds go but its cheap for a reason. It has been a major source of frustration that I worked very hard to solve and I hope you take the same steps so you don't end up chasing the leaks.
Thank you Dev.
Had notice the lack of internal pipe compressing the donut, Also, without a pressed metal ring insert this type of gaskets simply blows out.
Btw. on a slightly sidways not; I réally liked your explanation of why the engine bay of the MR does not run hotter than that of a front engined car. It is contrary to apparent ´logic´ but indiscutable when you explain it.
Quote from: Petrus on July 9, 2019, 16:13Thank you Dev.
Had notice the lack of internal pipe compressing the donut, Also, without a pressed metal ring insert this type of gaskets simply blows out.
Btw. on a slightly sidways not; I réally liked your explanation of why the engine bay of the MR does not run hotter than that of a front engined car. It is contrary to apparent ´logic´ but indiscutable when you explain it.
Flat gaskets can work but our OEM flanges are not exactly a flat arrangement and the gaskets these Chinese guys provide are some kind of two piece metal infused composite material that blows out between the layers because it cant handle the heat. On the exhaust side some have got away with placing the donut gasket in between but without support from a metal tube it just slides in time and leaks. Once you weld on this little extension it works great but by far one of the most important things that has saved me is the high temp thread locker.
This downpipe is flawed but if you can get it to work its good value and actually does increase horsepower unlike other bolt on modifications that do next to nothing.
In regards to the engine heat explanation you are the few that get it. No matter how many times I try to get though to people it becomes a futile exercise in making some understand that adding a fan does next to nothing, is counter intuitive because it places weight up high and places an unnecessary load on the cars electrical system.
A much better approach is to use shielding on the header to reduce the heat in the engine bay and it might actually help with exhaust scavenging helping exhaust flow.
The sandwhich type gasket will only survive with the pressed in ring stopping the gas from blowing between the outer layers.
About the locking fluid; will brass nuts not work? It is that they are a bit piggy to get to, otherwise locking wire would be my go-to. Ever since vintage Brit bikes and racing Italian beauties I have a roll of locking wire about. Makes a great hose clip too. Had one of those übercool spinning pliers too, but they were in my tool box that got stole >:D
A decat or smaller sports cat will do a lot to lower engine bay temp. because the OEM cat is a real heat sink.
This is the primairy reason why I would like to fit the ree flow mid pipe. Fingers crossed Nvy decides to actually sell his, otherwise I will order the El Cheapo and mod it to seal.
p.s. I think the engine room temp. would make a hot topic. for a seperate thread.
Quote from: Petrus on July 9, 2019, 20:06The sandwhich type gasket will only survive with the pressed in ring stopping the gas from blowing between the outer layers.
About the locking fluid; will brass nuts not work? It is that they are a bit piggy to get to, otherwise locking wire would be my go-to. Ever since vintage Brit bikes and racing Italian beauties I have a roll of locking wire about. Makes a great hose clip too. Had one of those übercool spinning pliers too, but they were in my tool box that got stole >:D
A decat or smaller sports cat will do a lot to lower engine bay temp. because the OEM cat is a real heat sink.
This is the primairy reason why I would like to fit the ree flow mid pipe. Fingers crossed Nvy decides to actually sell his, otherwise I will order the El Cheapo and mod it to seal.
p.s. I think the engine room temp. would make a hot topic. for a seperate thread.
I tried many different bolts including stainless and brass. I tried lock washers, double bolt, lock nuts and a very ingenious washer called a Nord lock. Look up Nord lock as they are pretty ingenious.
Eventually all of these bolts walked. The Nord lock worked great on some parts of the exhaust but the furthest rear loosens up.
I believe one of the problems is the surface of the downpipe is just too slippery and doesn't get a good bite with a lock washer.
Another problem could be my urethane engine mounts are transmitting a harmonic that is vibrates them free.
You can drill and wire bolts like they do for racing as that will stop the issue however I had to re-torque the bolts after they got hot and the gasket compressed. What I did after is remove the bolts and reapplied thread locker again and tightened everything up and its been good so far. Threadlocker is just very easy and less complicated if your specs change and now your wire doesn't fit though the holes.
If the high temp carbon gasket burns out I have a graphite gasket that Im going to try next which doesn't require re-torquing because once it crushes 50% it acts like a spring and it crushes to seal leaks from uneven flanges.
Its no point in explaining the engine heat issue, most will not get it even if you show them water temps and oil temps that do not align with their reasoning that they feel heat. The MR-S engine runs cool and can be overcooled when people add oil coolers and aftermarket thermostats.
Quote from: Dev on July 9, 2019, 22:30The MR-S engine runs cool and can be overcooled when people add oil coolers and aftermarket thermostats.
Those after market thermostats and higher pressure rad.caps make for yet anóther interesting thread topic. Apparently related to, but not quite the same as engine room temp.
The rad. cap pressure it quite simple: The higher pressure raises the boiling point a tad, allowing the coolant to get that bit much hotter.
The after market stat is more tricky as the opening temp can go either way. The trodden path is towoards a lower temp. That does not rime with the high pressure rad cap does it. Unless the cooling system is way insufficient. So, that high pressure rad cap should go with a stat opening at hígher coolant temp. which makes sense for engine efficiency.
Anyway, different subject and OEM is, bar extreme exceptions, best.
Quote from: Dev on July 9, 2019, 22:30I tried many different bolts including stainless and brass. I tried lock washers, double bolt, lock nuts and a very ingenious washer called a Nord lock. Look up Nord lock as they are pretty ingenious.
Eventually all of these bolts walked. The Nord lock worked great on some parts of the exhaust but the furthest rear loosens up.
I believe one of the problems is the surface of the downpipe is just too slippery and doesn't get a good bite with a lock washer.
Another problem could be my urethane engine mounts are transmitting a harmonic that is vibrates them free.
You can drill and wire bolts like they do for racing as that will stop the issue however I had to re-torque the bolts after they got hot and the gasket compressed. What I did after is remove the bolts and reapplied thread locker again and tightened everything up and its been good so far. Threadlocker is just very easy and less complicated if your specs change and now your wire doesn't fit though the holes.
If the high temp carbon gasket burns out I have a graphite gasket that Im going to try next which doesn't require re-torquing because once it crushes 50% it acts like a spring and it crushes to seal leaks from uneven flanges.
Thanks for that Nord lock referral. Did not know they are a thing, let alone they had a name. They are fitted under the front axle nuts of a retro bicycle I have.
I was not aware either that locking fluid for such a high temp application exists. Thanks for that too!
Retighning would make locking wire a pita yes.
If it recurs, you could try bolts/nuts with a fine thread. Torque them a bít tighter and they should stay put.
Quote from: Petrus on July 9, 2019, 23:17Quote from: Dev on July 9, 2019, 22:30I tried many different bolts including stainless and brass. I tried lock washers, double bolt, lock nuts and a very ingenious washer called a Nord lock. Look up Nord lock as they are pretty ingenious.
Eventually all of these bolts walked. The Nord lock worked great on some parts of the exhaust but the furthest rear loosens up.
I believe one of the problems is the surface of the downpipe is just too slippery and doesn't get a good bite with a lock washer.
Another problem could be my urethane engine mounts are transmitting a harmonic that is vibrates them free.
You can drill and wire bolts like they do for racing as that will stop the issue however I had to re-torque the bolts after they got hot and the gasket compressed. What I did after is remove the bolts and reapplied thread locker again and tightened everything up and its been good so far. Threadlocker is just very easy and less complicated if your specs change and now your wire doesn't fit though the holes.
If the high temp carbon gasket burns out I have a graphite gasket that Im going to try next which doesn't require re-torquing because once it crushes 50% it acts like a spring and it crushes to seal leaks from uneven flanges.
Thanks for that Nord lock referral. Did not know they are a thing, let alone they had a name. They are fitted under the front axle nuts of a retro bicycle I have.
I was not aware either that locking fluid for such a high temp application exists. Thanks for that too!
Retighning would make locking wire a pita yes.
If it recurs, you could try bolts/nuts with a fine thread. Torque them a bít tighter and they should stay put.
I don't know. I tried everything but in the end the high temp thread locker worked exceptionally well that it makes all other solutions obsolete. Regular thread locker would just melt but the stuff I have is rated to 2000 degrees F.
https://www.ebay.com/itm/Resbond-907ts-High-Temp-Threadlocker-2mL-Blue-Free-First-Class-Mail/113692285387?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Thanks for the link. One to bookmark!