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Crikey Stuart,

Those pictures show a very different story to the Phoenix super sport cross box system on my car where the twin pipes end over 3 inches before the rear of the bumper.

Anyone else got this system (with the Phoenix manifold) so I can compare positioniong?

The pipes in your pictures appear to be an inch or two beyond the bumper.

I am now wondering if my system was fitted incorrectly during a recent (disappointing) restoration.

Anyone know where I can get some stainless steel extensions with an inside diameter of 57mm (2 1/4 inch)?

I have supposedly had a CP150 cam fitted to my CR car but I have no idea whether the metering unit springs were changed. (somehow I doubt it)

The car is rather sluggish and unresponsive so I may have more than one thing contributing to my fumes.

Thanks for all your ideas and help.

Regards

Les

 

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5 hours ago, Les Pettitt said:

Thanks Yankee,

I am noticing the problem with the top down, my breezebreaker in place and the windows up so I think it is swirling fumes from the exhaust being sucked back over the top of the car but I could be wrong as I also get a lot of fumes in the boot (trunk).

Talking with Derek Graham (TR6 Registrar) he told me the boot seal should meet at the front (nearest the filler cap) and the joint taped over, but needless to say mine had the joint near the lock and no tape.

I like your idea of checking all the other seals and the use of a CO2 meter.

I recently replaced the fuel tank and had to cut down the foam washers that fit round the drain plugs so will check that area.

The problem has got much worse since the car was 'restored' and the old mild steel exhaust system replaced by a stainless steel one. As I said earlier the SS exhaust finishes 3 inches before the bumper whereas the old one was flush with the bumper. 

Does anyone think tail pipe extensions would help?

My wife refuses to come in the car until this is sorted so I have to do something.

Thanks for your suggestions, it has given me few things to try that I would not have thought of.

Regards

Les

Hi Les,

Your comments are very interesting. I mentioned a similar situation earlier in the post, windbreaker, windows up and low speeds is when it’s most noticeable.

I have a stainless steel exhaust pipe system but it is as per original set up with the 2 pipes coming out together on the passenger side of the car. Mine protrude about 2 to 2.5 inches beyond the rear bumper, so I don’t think pipe extensions are the answer.

It looks to me as if getting the engine tuned right is a key factor. Mine isn’t bad but I think it runs a bit rich. I’ve done all I know to do, with timing, tappets even injectors, etc. But I don’t feel confident making adjustments to the MU so I might get that done by someone who knows what they’re doing. It would be great to solve this issue, because, whilst my wife will still come out in the car, it does take the edge off the enjoyment.

Cheers, Rob.

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Hi Rob,

I'm sure you are right and getting the MU sorted and matched to the cam would be a good start. However, like you I don't feel confident messing with the MU. I have never touched the MU myself in 43 years of ownership and I am going to have to take a deep breath before I lift the lid to see what springs I have fitted.

I am rather disppointed to hear you think tail pipe extensions would make no difference. If yours protrude 2.5 inches beyond the bumper and mine stop short of the bumper by over 3 inches, yours end 6 inches further back than mine. My Phoenix system also has two pipes coming out together on the passenger side so it looks almost standard but with larger bore pipes and, as I am now finding, set much further forward.

I think I have found a supplier of 57mm i/d stainless steel pipe and for the few quid it costs I am very tempted to buy a metre and extend my pipes by say 6 or 7 inches and see if I notice a difference.

I will also take a look under the car and see how my back box is mounted in case my restorer cut down my central pipe (or used the wrong one) and welded a new lug on the back box thus taking it further forward than it should be. Anything is possible.

Best wishes

Les

 

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14 hours ago, Mike C said:

Sorting out the MU and injectors is best done on an original Lucas calibration bench or similar. I don't have one so I send the equipment to someone that does rather than fiddle with it myself.

Hi Mike,

Just curious as to where you find someone with a Lucas calibration bench ( and requisite skills ... ) in Melbourne ?

I had my MU rebuilt and calibrated about 30 yrs ago by a guy in Perth, but I don't believe he any longer has the equipment.

Cheers, Robin C 

   

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Hi All,

Just thought I would show you the position of my exhaust. As you can see it ends before the bumper starts although the strap appears to be in the correct place.

As Moss sell these I have asked them if they have come across the fume problem before with it.

There is quite a difference between my exhaust end position and those on the pictures Stuart posted.

Regards

Les

Exhaust position.JPG

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9 hours ago, RobinC said:

Hi Mike,

Just curious as to where you find someone with a Lucas calibration bench ( and requisite skills ... ) in Melbourne ?

I had my MU rebuilt and calibrated about 30 yrs ago by a guy in Perth, but I don't believe he any longer has the equipment.

Cheers, Robin C 

   

I don't know of any in Melbourne. I've had some high priced disasters with the Melbourne experts in  the past. I used Peter Bower in Sydney:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwi46dumparzAhXcyjgGHdTKC5EQjBB6BAgKEAE&url=https%3A%2F%2Fbowerpower.com.au%2F%3Fpage_id%3D247&usg=AOvVaw1lrerKhjKZhW-7pbMCU0cp

He has the original Lucas Australia calibration & test gear. The problem is ,in the past few years his source of viton TR6 MU elastomers has dried up so he's reluctant to work on TR6 MU's. Next time I need him I'll have to source my own components and give them to Peter with the MU. It's his test equipment & expertise  I really need.

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Hi fat jon

i don t know if it can help but i had the same problem with exhaust fumes in the car in any circonstances. I could not cope with it any more (btw i have the same 2 pipes exhaust). So After reading all threads on the subject i isolated the trunk by sticking thick gommet all around the lid and isolated trunk from cockpit by sticking very carefully a shower curtain at the place where some implement a firewall

 

said like that it looks like dirty DIY but nobody can see :-) and the result is really acceptable for me

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I have had this problem and like some my clothes smelled of exhaust fumes after a relatively short drive. I fitted a new boot seal and improved the contact by putting a small rope cord in the seal before fitting. Checked the seals around rear lights all good. I tried tail pipe extensions on a standard exhaust system (they finished about 2" past the bumper as standard ), they certainly made a difference but I kept catching my ankles as I walked past the car in the garage so they came off, also not sure they look right ! I then tried a mesh windbreak, again this improved the situation so when I fitted a roll bar I put a perspex wind break inside, and at the same time installed an aluminium fire wall... issue 90% sorted. Will probably look at having the MU looked at this winter.

I think it's a process of trying all the recommendations provided by the members as I have and hopefully you will get there.

 

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Edited by Phil H 4
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I massively reduced the fumes smell in the boot by putting a plastic seal where some put the firewall…..just plastic sheet but well sealed, as mentioned earlier in this post by Jctr6EFI72. I think a low pressure zone forms in the cabin which pulls the air from the back of the car through the boot. If you can seal the boot of course this will stop it I guess but it’s pretty hard to do practically. 
I was really happy with this, but now with my polycarbonate  windbreaker and windows up I am back to fumes in the cabin.

Keith I think you can reduce the smell in the boot by either improving the seals to the boot or between the boot and the cabin or both.

Cheers, Rob

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3 hours ago, Rob Y said:

I massively reduced the fumes smell in the boot by putting a plastic seal where some put the firewall…..just plastic sheet but well sealed, as mentioned earlier in this post by Jctr6EFI72. I think a low pressure zone forms in the cabin which pulls the air from the back of the car through the boot. If you can seal the boot of course this will stop it I guess but it’s pretty hard to do practically. 
I was really happy with this, but now with my polycarbonate  windbreaker and windows up I am back to fumes in the cabin.

Keith I think you can reduce the smell in the boot by either improving the seals to the boot or between the boot and the cabin or both.

Cheers, Rob

Looking back at my diary, I installed a steel firewall between the cockpit and the boot in the same winter I had the MU rebuilt. The firewall was fully sealed with Sikaseal 670 Fire so it's pretty airtight. Maybe that was what cured my fume problem.

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On 9/30/2021 at 10:04 AM, Tim D. said:

I use tailpipe extensions on a standard exhaust and it made a big difference when I was on PI.

Tim

When I fitted a s/s exhaust years ago I made the mistake of entering the exhaust pipe tubes too far into each other which meant that the exhaust pipers did not protrude beyond the bumper and I had to rehang them. This cured the problem of exhaust fumes.

Bruce.

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Unless you have efi I would urge caution with leaning off the mixture on the PI cars.

The fuelling is a compromise. Lean it off low down in the rev range and you risk it going lean higher up impairing performance with potential damage in the long run.

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Hi All,

Thanks for all your thoughts.

Keith, do you have a single pipe going into your silencer (ie do you have the super sport cross box system like me)? My pipes are less than 500mm from the rear of the box.

I don't see how I could move the box backwards as the lugs it hangs on look to be in the right place. How did you get over this Bruce?

I think I need to try a few things. Move the boot seal so the join is at the front by the fuel cap and not at the back above the lock and tape over the joint. Plug the holes in the spare wheel well, plug the holes were the original fuel filter went. Look at the holes for the tank drains and seal if necessary.

Install a firewall either plastic or ali.

Try pipe extensions but this doesn't seem to be a cure all.

Get my metering unit looked at. I still think there is a mismatch between my supposed CP150 cam and probably a stock CR MU.

The chap from Moss told me his son has the exact same exhaust as me and it is in the same place and he gets no fumes. He suggested the boot seal as the culprit.

I'll let you know when I find the cure which I will have to do as my wife has asthma and is very sensitive to fumes, dust etc.

Thanks again everyone.

Regards

Les

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45 minutes ago, Les Pettitt said:

Hi All,

Thanks for all your thoughts.

Keith, do you have a single pipe going into your silencer (ie do you have the super sport cross box system like me)? My pipes are less than 500mm from the rear of the box.

I don't see how I could move the box backwards as the lugs it hangs on look to be in the right place. How did you get over this Bruce?

I think I need to try a few things. Move the boot seal so the join is at the front by the fuel cap and not at the back above the lock and tape over the joint. Plug the holes in the spare wheel well, plug the holes were the original fuel filter went. Look at the holes for the tank drains and seal if necessary.

Install a firewall either plastic or ali.

Try pipe extensions but this doesn't seem to be a cure all.

Get my metering unit looked at. I still think there is a mismatch between my supposed CP150 cam and probably a stock CR MU.

The chap from Moss told me his son has the exact same exhaust as me and it is in the same place and he gets no fumes. He suggested the boot seal as the culprit.

I'll let you know when I find the cure which I will have to do as my wife has asthma and is very sensitive to fumes, dust etc.

Thanks again everyone.

Regards

Les

Dont forget rear lamp seals and number plate lamps too.

Stuart.

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I recently bought a new boot seal from TRGB which was about 50% taller than the one I fitted 5 years ago following a paint job. I now have to push the boot down compressing the seal, before the catch engages. With the old one the boot rattled on the catch, so clearly had an air gap. A significant reduction of smell in the boot, her in doors is much happier. Happy wife, happy life.

Mick

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The point about a possible mismatch between a CP cam and a CR MU, you need to check your Hg level, put a vacuum gauge on the intake side (servo pipe), and that'll tell you whether you have the vacuum level of a CP or CR, then take the top off the MU and see what colour springs it has and if it's incorrect, see about getting it set up for your application. 

Gareth

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Hi All,

Stuart, good points. As my car has just been fully rebuilt you would hope new seals had been used but I wouldn't bet on it. I'll check.

Mike, my boot is quite hard to shut (it needs a good push) so I am hoping that moving the seal around so the split is behind the fuel filler cap and then taping over the joint will sort out that part of the problem. Any rags etc left in the boot stink so well worth me sorting out all ways of fumes getting into the boot.

Gareth, yes, I need a vacuum gauge. Any recommendations? What scale is needed? A vacuum gauge like the two I put in the dash of my Vitesse 2 litre mk 2 because I liked watching the needles move? I am still trying to summon the courage to take the top off the MU (never fiddled with this before) to check the springs. It would be good to know for sure if I have a cam/MU incompatibility sooner rather than later so I can look for other problems if necessary.

My intention is to take it to Revington to let them put it on their rolling road and sort out my lack of power but I need to do a few hundred more miles of running in before I go.

Thanks everyone, I have plenty to get on with now.

Regards

Les

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14 minutes ago, Les Pettitt said:

Hi All,

Stuart, good points. As my car has just been fully rebuilt you would hope new seals had been used but I wouldn't bet on it. I'll check.

 

Thanks everyone, I have plenty to get on with now.

Regards

Les

The new rear light seals are soft sponge and sometimes come in two pieces, they arent a very good seal and when I fit them I use non setting windscreen sealer on both sides and make sure the lamps are clamped up tight. You need to be careful how you tighten them in as they have fixings on both sides so need doing up bit by bit going round to get them to pull in correctly

Stuart.

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Hi Les

Mine is not the Super Sports type and is a six into two manifold then a single pipe going back into two at the rear box, sticks out beyond the bumper my shins can prove that!

Mine is on EFI so engine should be running as it should so will go for a new boot seal the one fitted has been on a good twenty years.

Keith

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I suffer with cabin fumes - most noticeable on the overrun - and long runs leave the boot and my clothes with a eau d'petrol.  My PI is set up correctly btw and was again looked at by Carl (TR Trader) in July so I know that's not teh issue.  

Windbreaker made little difference so I bought one of these https://www.amazon.co.uk/gp/product/B0842W36SR/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

Looks terrible fitted but it makes a very noticeable difference.  I just need to find a solution now which is better on the eye. My exhaust tip otherwise sits pretty much flush with the end of the bumper as pic below

 

 

roof down.jpg

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