Cerbera - Initial Assessment
Discussion
Well my baby is in for her 1st service since I acquired her.
Andy Bennett is giving her a good look over, and so far:
De-catted already - however, apparently the AJP8s do not need decatting as they were shipped with metallic catalytic convertors (not ceramic), and there is no loss of performance with these cats. This is not widely known it seems. Looks like I may have to get some cats refitted to get it through the MOT in October. Bugger. Makes me wonder how she's passed MOT for the last few years as it seems the cats were removed in 2007 according to the list of receipts.....hmmmm....
Someone has installed an exhaust cross-over which isn't requiredand apparently will rob the engine of power. Interesting as it seems that a "Race Specialist" garage installed it on behalf of one of the previous owners.
Small crack in intake manifold which may be causing a small amount of excess oxygen to be detected, thereby causing overfuelling - hence the slight sniff of fuel from the engine.
Poorly fitted rubber hose pipe between filler cap & tank - causing fuel vapour to leak and therefore contributing the stronger fuel smell, and if overfilled will cause seepage into the boot.
And now I'm waiting for the full list tomorrow......fingers' crossed that there isn't anything else too serious.
Mike
Andy Bennett is giving her a good look over, and so far:
De-catted already - however, apparently the AJP8s do not need decatting as they were shipped with metallic catalytic convertors (not ceramic), and there is no loss of performance with these cats. This is not widely known it seems. Looks like I may have to get some cats refitted to get it through the MOT in October. Bugger. Makes me wonder how she's passed MOT for the last few years as it seems the cats were removed in 2007 according to the list of receipts.....hmmmm....
Someone has installed an exhaust cross-over which isn't requiredand apparently will rob the engine of power. Interesting as it seems that a "Race Specialist" garage installed it on behalf of one of the previous owners.
Small crack in intake manifold which may be causing a small amount of excess oxygen to be detected, thereby causing overfuelling - hence the slight sniff of fuel from the engine.
Poorly fitted rubber hose pipe between filler cap & tank - causing fuel vapour to leak and therefore contributing the stronger fuel smell, and if overfilled will cause seepage into the boot.
And now I'm waiting for the full list tomorrow......fingers' crossed that there isn't anything else too serious.
Mike
mickydoo said:
Well my baby is in for her 1st service since I acquired her.
Andy Bennett is giving her a good look over, and so far:
De-catted already - however, apparently the AJP8s do not need decatting as they were shipped with metallic catalytic convertors (not ceramic), and there is no loss of performance with these cats. This is not widely known it seems. Looks like I may have to get some cats refitted to get it through the MOT in October. Bugger. Makes me wonder how she's passed MOT for the last few years as it seems the cats were removed in 2007 according to the list of receipts.....hmmmm....
Mike
I will be taking my Cats out, main reason is to bring the in Cabin Temp down in the summer when in heavy traffic as they get very hot under your bum lol.Andy Bennett is giving her a good look over, and so far:
De-catted already - however, apparently the AJP8s do not need decatting as they were shipped with metallic catalytic convertors (not ceramic), and there is no loss of performance with these cats. This is not widely known it seems. Looks like I may have to get some cats refitted to get it through the MOT in October. Bugger. Makes me wonder how she's passed MOT for the last few years as it seems the cats were removed in 2007 according to the list of receipts.....hmmmm....
Mike
I don't think they make any odds to help getting it through a Mot, Better to find a TVR friendly Tester.
If you want some 'Cat' info I may be able to find out some details of mine.
Apparently they were made by a firm local to me as a prototype to ensure you don't need to keep swapping them in and out come MOT time. They give a really good sound with straight through pipes and given enough of a warm up may help pass an MOT.
This is all circumstantial but apparently the originals are 400 cell ceramic and mine are 200 cell metallic, no idea what all that means BTW.
Apparently they were made by a firm local to me as a prototype to ensure you don't need to keep swapping them in and out come MOT time. They give a really good sound with straight through pipes and given enough of a warm up may help pass an MOT.
This is all circumstantial but apparently the originals are 400 cell ceramic and mine are 200 cell metallic, no idea what all that means BTW.
Andy was one of the original TVR engineers from Westover sports cars years and years ago. He allegedly knew John Ravenscroft very well & he picked up a lot of knowledge transfer from him over the years, and was involved with the TVR team that was at Le Mans in 2003. I was incorrect in my previous post where I stated 1993. (The chap that collected my car today was very enthusiastic about Andy's in depth knowledge)
In conversations we've had he seems extremely knowledgeable about the engine and states that a lot of the so-called experts do not actually know the engine not worked with it in terms of race modifications etc
I'd trust his experience over someone less obviously qualified....
In conversations we've had he seems extremely knowledgeable about the engine and states that a lot of the so-called experts do not actually know the engine not worked with it in terms of race modifications etc
I'd trust his experience over someone less obviously qualified....
Even metallic foil cats, even though they are less restrictive than ceramic honeycomb, will still reduce exhaust gas flow. Removing them will reduce back pressure and improve power. Mid range torque may reduce due to the removal of the pressure wave reflections in the system but this isn't huge due to the distance they are from the ports.
Try asking him about the poor manifold design or the mapping? See what his views are on that.
Catalyst removal on these cars is proven to increase power.
Try asking him about the poor manifold design or the mapping? See what his views are on that.
Catalyst removal on these cars is proven to increase power.
The so-called experts on here have been proven correct so I'm sure his comments were more specific...?
A poor factory map plus cats isn't getting the best from a cerb. Remove the cats and you'll see little or no improvement to power afaik. A decent map will get the most power without cats, bizarrely the linked decats are even better.
Do you work in marketing ;-)
A poor factory map plus cats isn't getting the best from a cerb. Remove the cats and you'll see little or no improvement to power afaik. A decent map will get the most power without cats, bizarrely the linked decats are even better.
Do you work in marketing ;-)
Gazzab said:
The so-called experts on here have been proven correct so I'm sure his comments were more specific...?
A poor factory map plus cats isn't getting the best from a cerb. Remove the cats and you'll see little or no improvement to power afaik. A decent map will get the most power without cats, bizarrely the linked decats are even better.
Do you work in marketing ;-)
A poor factory map plus cats isn't getting the best from a cerb. Remove the cats and you'll see little or no improvement to power afaik. A decent map will get the most power without cats, bizarrely the linked decats are even better.
Do you work in marketing ;-)
Talk is cheap.
A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
julian64 said:
Talk is cheap.
A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
Because it was a business trying to make money. Same could be said why are the chassis utter crap on them as well why did they not galvanize them to stop the rot. And use stainless steel bolt where they could. A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
I guess they have to draw a line on spending some where to be able to sell them for what they did.
scotty_d said:
julian64 said:
Talk is cheap.
A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
Because it was a business trying to make money. Same could be said why are the chassis utter crap on them as well why did they not galvanize them to stop the rot. And use stainless steel bolt where they could. A TVR engineer has a lot to answer for in terms of in what state the AJP8 came out of the factory.
A few times we have had them on this forum, and when the more glaring problems with the AJP8 have been pointed out the answer is always the same. The factory restricted the money.
In truth a number of indies have vastly improved the power, driveability and reliability of the engine for not a lot of money.
You have to ask yourself why they couldn't have done that in the first place.
I guess they have to draw a line on spending some where to be able to sell them for what they did.
But even forgeting the engine, the general build quality was dire, and for the want of some cheap as chips alterations the car improves. Blaming the budget tends to ring a bit hollow when I'm staring at a cable tie holding a water thermostat banging on the frame for the want of a 10p bracket. Examples like that are legion on this particular car.
Julian,
I cannot disagree with you - but with eng dev it's not just money, it's time as well.
I suspect those designing & rolling the car out had none of both - that's when corners need to be cut.
If you have many years to sit back and mull over certain aspects of the car, you'll find 'cheap' ways of sorting things that, in retrospect, should have been done vastly differently. Corners get cut and bodges get bodged when you've got to have the car out next tuesday. That's when I reach for the zip tie and to hell with the 10p custom bracket!
(These views to not represent those of my employer!)
I cannot disagree with you - but with eng dev it's not just money, it's time as well.
I suspect those designing & rolling the car out had none of both - that's when corners need to be cut.
If you have many years to sit back and mull over certain aspects of the car, you'll find 'cheap' ways of sorting things that, in retrospect, should have been done vastly differently. Corners get cut and bodges get bodged when you've got to have the car out next tuesday. That's when I reach for the zip tie and to hell with the 10p custom bracket!
(These views to not represent those of my employer!)
Some interesting reading here on exhaust tuning on the 4.5
http://2009.tvrspeedchampionship.co.uk/index.php?o...
http://2009.tvrspeedchampionship.co.uk/index.php?o...
TVdinneR said:
Some interesting reading here on exhaust tuning on the 4.5
http://2009.tvrspeedchampionship.co.uk/index.php?o...
I have a nice Julian exhaust. So called expert that he is ;-) http://2009.tvrspeedchampionship.co.uk/index.php?o...
Byker28i said:
I took my cats out to stop the cabin/gearbox/clutch heating up. The other thing they add is 8-10db of noise reduction, without them pops and bangs on backfire are more pronounced as well. I put mine back in for the mot.
Do you just run straight pipes in place of the cats?I am going to see how loud my new exhaust is first before i remove them. I want it a little louder than standard. I might have to get 2 small sports silencers made up instead of straight through pipes.
As it was far to loud with the old system great for pops and bangs but it drones at all the wrong speeds 30 50 and 70 lol
Gazzab said:
TVdinneR said:
Some interesting reading here on exhaust tuning on the 4.5
http://2009.tvrspeedchampionship.co.uk/index.php?o...
I have a nice Julian exhaust. So called expert that he is ;-) http://2009.tvrspeedchampionship.co.uk/index.php?o...
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