The Lotus Cars Community banner
1 - 13 of 13 Posts

·
Registered
2005 Elise - Graphite Gray w/Touring & Sport Pkg
Joined
·
41 Posts
Discussion Starter · #1 ·
Hello LT,

I recently bought a used OBX header from a fellow LT member for my Elise. He missed the donut gasket (between header exit and midpipe) when he packed it, no big deal. I am trying to find a good replacement or ask where to find a suitable part number for it. I’ve been searching online for this without luck.

1. Will the OEM donut work/fit?
2. Should I take the header to the auto part store and try to find one that fits properly?
3. What should I be looking for fitment-wise?

Yes, I emailed OBX over a week ago, no response.

Thank you in advance.

Eric
Bicycle part Automotive lighting Font Nickel Auto part
 

·
Administrator
Joined
·
7,564 Posts
You have the answers in your header. Measure it then look at OBX donuts on ebay and match up. If you luck out and same dimensions as OEM MWR has them. You'll have to do some investigating. When you pay 300 vs 1000+ there will be issues. You can try and match up at auto parts if they have a selection to pick from.
 
  • Like
Reactions: ChromeThndr

·
Registered
Adding lightness with an angle grinder.
Joined
·
143 Posts
I MAY have one that will work. Take some pics with dimensions. Also, where are you located? I'll send you what I have if you're in the states and it fits. It should be a generic part... 2.5" I think.
 
  • Like
Reactions: ChromeThndr

·
Registered
2005 Elise - Graphite Gray w/Touring & Sport Pkg
Joined
·
41 Posts
Discussion Starter · #4 ·
I MAY have one that will work. Take some pics with dimensions. Also, where are you located? I'll send you what I have if you're in the states and it fits. It should be a generic part... 2.5" I think.
Thank you Node, Im in Texas.

I’ll take some measurements with pictures in the morning
 

·
Registered
Joined
·
322 Posts
Looks like oem 2ZZ gasket -
Toyota part - Exhaust Manifold (Donut) Gasket (2ZZ) # 17451-0D040
or Fel-Pro 61190
Looks as though OBX use the Toyota spring and flange plate system. If so then good idea if you go to Toyota shop to also get new springs -
Compression Springs (2) manifold to downpipe (2ZZ) 90501-35037*
*These springs are used on other Toyota models. They are approx 40mm long extended.
 

·
Registered
Adding lightness with an angle grinder.
Joined
·
143 Posts
I agree, those springs are crap and shouldn't be reused. If that is the same OEM doughnut then yes I do have one laying around. However, they are also in stock at just about all Autozone etc.. auto parts places. You could have it right away for like $5 rather than waiting on me to send you a part that has been sitting on my self for who knows how long LOL. Again, if for some reason you can't find it locally let me know and Ill send one along through the USPS.

If you're in Texas, I strongly urge you to cut that crap doughnut fitting off and weld on a Vband and perhaps a flex section.

I got tired of replacing that crap each time I removed my exhaust.
Product Automotive exhaust Gas Nickel Cylinder
 

·
Registered
2005 Elise - Graphite Gray w/Touring & Sport Pkg
Joined
·
41 Posts
Discussion Starter · #8 ·
Here are pictures of the measurements. It looks like the header side has an outer diameter of aprox 62mm, the midpipe side about 89mm at its widest section. The bolts are 90mm long (I know I measured it wrong on the picture). @iana you are right, my bolts can use an upgrade plus I think they are extremely long since the flanges are about 50mm apart without the donut gasket.

I apologize for the crappy measurements, I need to get me a caliper.
Tape measure Hand tool Tool Wood Material property
Office ruler Amber Tape measure Measuring instrument Insect
Automotive tire Gas Rim Automotive wheel system Circle
Automotive tire Amber Material property Automotive lighting Gas



I MAY have one that will work. Take some pics with dimensions. Also, where are you located? I'll send you what I have if you're in the states and it fits. It should be a generic part... 2.5" I think.
No worries about sending me one. I should be able to source one locally. I truly appreciate your offer, thank you.

I also replaced my shitty donut joint with a section of flex pipe back in the day
Thats a good idea.
 

·
Registered
Adding lightness with an angle grinder.
Joined
·
143 Posts
Don't let you neighbors know you have a metric tape measure! I think that's against the law in TX.
 
  • Like
Reactions: ChromeThndr

·
Registered
2005 Elise - Graphite Gray w/Touring & Sport Pkg
Joined
·
41 Posts
Discussion Starter · #10 ·
Don't let you neighbors know you have a metric tape measure! I think that's against the law in TX.
I was stationed in Germany a few years ago and I bought one at the local hardware store. Its very handy…. And a collectors item in TX


Sent from my iPhone using Tapatalk
 

·
Administrator
Joined
·
7,564 Posts
Post #6 is a Walker chart that you can plug your dimensions in and find suitable part ForcedFed header Donut
 
  • Like
Reactions: ChromeThndr

·
Registered
Joined
·
322 Posts
Looks like takes 2ZZ donut gasket as per above.

That fixing system cannot hold springs in a set position to maintain compression and bolts will move around and needs to be re-engineered to perform properly.

Top flange should be threaded for bolt so that that platform is fixed. Maybe get some nuts welded onto the top of the top flange to fix.

Then needs some 11-12 mm ID steel tube sections that sit against the fixed top flange and go through the bottom flange. Tube OD should be about 15-16mm (To clear inside of oem spring of 17mm)

Measure inside distance between flange plates, with donut gasket firmly in place.

Add thickness of lower flange plate.

Add height of compressed spring in a vice - leaving 1.0 mm or so between coils.

The total is the length of 2 tube sections needed.

Drill out lower plate to the OD of the spacer tube.

Bolt with 1" dia washer and spring with tube spacer going in from under bottom plate.(pic 2)

Assemble on the bench to check spring compression. If not enough compression, then add washer under spring. You will need to file ID of these spacer washers out to clear OD of tube spacer so that spring only is resting against the washer, not under the tube section. Easier alternative is to trim tube sections down to size, or make new longer tube sections if spring is too compressed. You should be able to force trumpet to move on donut, as it will in operation.

Should have enough bolt length to be able to put a lock nut on top of welded nut on top flange plate - to stop bolt from working loose.

PS: Your bolt looks like is 1.5 thread pitch which is ok if you have lock nut on top of upper flange plate. Oem thread pitch is 1.25.

First pic of the lower flange plate. The tube sections pass though this plate. Add a lock nut above top plate.

Second pic is lower plate ready to thread into upper plate. The protruding tube sections lock against underside of top flange plate.
Grey Font Material property Nickel Circle
Bicycle part Nickel Auto part Household hardware Cylinder
 

·
Registered
Adding lightness with an angle grinder.
Joined
·
143 Posts
Looks like takes 2ZZ donut gasket as per above.

That fixing system cannot hold springs in a set position to maintain compression and bolts will move around and needs to be re-engineered to perform properly.

Top flange should be threaded for bolt so that that platform is fixed. Maybe get some nuts welded onto the top of the top flange to fix.

Then needs some 11-12 mm ID steel tube sections that sit against the fixed top flange and go through the bottom flange. Tube OD should be about 15-16mm (To clear inside of oem spring of 17mm)

Measure inside distance between flange plates, with donut gasket firmly in place.

Add thickness of lower flange plate.

Add height of compressed spring in a vice - leaving 1.0 mm or so between coils.

The total is the length of 2 tube sections needed.

Drill out lower plate to the OD of the spacer tube.

Bolt with 1" dia washer and spring with tube spacer going in from under bottom plate.(pic 2)

Assemble on the bench to check spring compression. If not enough compression, then add washer under spring. You will need to file ID of these spacer washers out to clear OD of tube spacer so that spring only is resting against the washer, not under the tube section. Easier alternative is to trim tube sections down to size, or make new longer tube sections if spring is too compressed. You should be able to force trumpet to move on donut, as it will in operation.

Should have enough bolt length to be able to put a lock nut on top of welded nut on top flange plate - to stop bolt from working loose.

PS: Your bolt looks like is 1.5 thread pitch which is ok if you have lock nut on top of upper flange plate. Oem thread pitch is 1.25.

First pic of the lower flange plate. The tube sections pass though this plate. Add a lock nut above top plate.

Second pic is lower plate ready to thread into upper plate. The protruding tube sections lock against underside of top flange plate.
View attachment 1299473 View attachment 1299474
OR.... and hear me out here. Install a flex section plus VBand and be done. $40 to never have to deal with that crappy connection again is worth it.

With an OBX header it's going to crack and need to be removed for welding anyway. May as well save yourself some headaches if you already know you're going to have to pull the header every 20k miles.
 
  • Like
Reactions: ChromeThndr
1 - 13 of 13 Posts
Top