Performance

[waterhouses]

Owned the car for c.1 month now and thoroughly enjoy it (apart from the bonnet). My everyday car is a 335D BMW so I am used to plenty of 00mph. I appreciate we are talking light years between the BMW and the TR6 (and the Tr6 was brought for enjoyment not speed) however last weekend I decided to test my TR6's performance as I'm not convinced its performing as it should be. My car is the 125bhp PI CR model manufactured in 1973 and achieved the 0-60 benchmark run in 15.5 seconds. Is this a respectful time or am I missing something that needs further investigation.

Look forward to your responses.

[alan atkinson]

That's about 6 seconds shy of what it was tested at back in the day...

[waterhouses]

That's about 6 seconds shy of what it was tested at back in the day...

 

That's what I thought, although I guess that car was the 150bhp model.

[foster461]

Owned the car for c.1 month now and thoroughly enjoy it (apart from the bonnet). My everyday car is a 335D BMW so I am used to plenty of 00mph. I appreciate we are talking light years between the BMW and the TR6 (and the Tr6 was brought for enjoyment not speed) however last weekend I decided to test my TR6's performance as I'm not convinced its performing as it should be. My car is the 125bhp PI CR model manufactured in 1973 and achieved the 0-60 benchmark run in 15.5 seconds. Is this a respectful time or am I missing something that needs further investigation.

Look forward to your responses.

 

 

It is not an order of magnitude off but is seems a bit high. The US spec cars where good for 12 to 14 seconds zero to 60 but they were seriously lobotomized and I would have expected the later PI cars to be in the 10-12 second range.

 

Stan

 

[Alec Pringle]

If a PI 6, CP or CR, can't hit 60 in under 10 seconds then there's something wrong with it. Or with the driver.

 

End of discussion.

 

Cheers,

 

Alec

[Mk1PI]

Every half decent standard TR5 or 6 that I have seen do a true 1/4 mile test and been driven reasonably hard ie changing gear at +5500rpm and aggressive off the line has turned in a low 16sec time 16.1-16.4 normally being the range depending on technique. Well modified ones easily go into the 15's and my old saloon managed a 14.8.

 

A 16.2 1/4 mile corresponds to roughly a ~9sec 0-60 mph time but dirty plugs, retarded ignition, dodgy injector/s or lack of fuel pressure etc can easily add a second or two to the time.. I have seen it happen... a perfectly healthy car capable of 16.1secs do a 18.0sec run because of fouled plugs leading to very poor top end power.

Edited February 24, 2010 by Mk1PI

[waterhouses]

Every half decent standard TR5 or 6 that I have seen do a true 1/4 mile test and been driven reasonably hard ie changing gear at +5500rpm and aggressive off the line has turned in a low 16sec time 16.1-16.4 normally being the range depending on technique. Well modified ones easily go into the 15's and my old saloon managed a 14.8.

 

A 16.2 1/4 mile corresponds to roughly a ~9sec 0-60 mph time but dirty plugs, retarded ignition, dodgy injector/s or lack of fuel pressure etc can easily add a second or two to the time.. I have seen it happen... a perfectly healthy car capable of 16.1secs do a 18.0sec run because of fouled plugs leading to very poor top end power.

 

The plugs are all new as is 1 injector. All fuel lines pulse well. Maybe I need to check fuel pressure and timing. Can you suggest an appropriate pressure tester capable of reading up to 120psi? I have the twin sports box, one of the silencers sounds very rattly, suspect the baffles are shot, can this also affect performance drastically?

[88V8]

The plugs are all new as is 1 injector. All fuel lines pulse well. Maybe I need to check fuel pressure and timing. Can you suggest an appropriate pressure tester capable of reading up to 120psi? I have the twin sports box, one of the silencers sounds very rattly, suspect the baffles are shot, can this also affect performance drastically?

 

The twin rear boxes tend to suffer from ground contact, but unless the silencer is blocked it will have no effect. If its baffles have blown out that would affect back-pressure which can be detrimental, but you'd hear it.

 

Test kit from here:

 

http://www.hydrotech...co.uk/index.htm

 

Pressure gauge: 0-160psi, 63mm dia. #9801-160.

Test point Tee 3/8" BSP (goes permanently betwixt metering unit and input flexible) #SNA02

Hose assy microbore 1000mm long #S100-AC-FA-01.00

 

Malcolm at Prestige also does a test kit.

http://www.prestigeinjection.net/

even though he still hasn't got round to mentioning it on his website.

He's a mine of information, and it would do you no harm to make contact. He will have thoughts on your performance deficit, and as he has restored a number of TRs his knowledge is not confined to the injection setup. He won't try and flog you stuff you don't need.

 

Ivor

[waterhouses]

The twin rear boxes tend to suffer from ground contact, but unless the silencer is blocked it will have no effect. If its baffles have blown out that would affect back-pressure which can be detrimental, but you'd hear it.

 

Test kit from here:

 

http://www.hydrotech...co.uk/index.htm

 

Pressure gauge: 0-160psi, 63mm dia. #9801-160.

Test point Tee 3/8" BSP (goes permanently betwixt metering unit and input flexible) #SNA02

Hose assy microbore 1000mm long #S100-AC-FA-01.00

 

Malcolm at Prestige also does a test kit.

http://www.prestigeinjection.net/

even though he still hasn't got round to mentioning it on his website.

He's a mine of information, and it would do you no harm to make contact. He will have thoughts on your performance deficit, and as he has restored a number of TRs his knowledge is not confined to the injection setup. He won't try and flog you stuff you don't need.

 

Ivor

 

Thanks for your help here Ivor will make contact with both

[RobinTR6]

I've had a couple or CR TR6's both long in the tooth and original engines. Not sure of the figures but even the twin SU ran faster than youre suggesting.

 

If the injectors are ok and doing the circular spray, easy to check, timing is reasonable and plugs and points etc are ok then I would have thought it would run considerably better than youre suggesting. For me I'd do all the basic checks which can be done with a few spanners and a bit of cardboard (spray from injectors), timing is easily manually by turning the dizzy etc and only then start getting more technical. or example if the pump isnt up to the job I'd have thought that you see that the injectors didnt have a decent and timed spray. I know that when ione is on the way out it often doesnt fire the petrol consistently even tho the pulse may be discernable in the connecting hose. Taking them out one by one and testing takes a few mins and that will tell you quite a bit. If youre not comfortable doing some of this stuff the forum has trained me up so takes a bit longer but you become more independant. There may be another knowledgeable member nearby or one of the 'reputrable specialists' with a quick visit may diagnose the problem in minutes and then decide how to proceed. I have replaced numerous MU etc and never had the need for a pressure test meter, albeit they are handy you may find that you only use it once so not a great investment.

 

 

FWIW

 

regards

Robin

[harrytr5]

I think a pressure meter is must.I have diagnosed many TRs, with a problem of pressure to the metering unit.I now have a collection of diagnostic tools gathered over the years to fully service my TR.Now the modern family car---forget it.

Regards Harry TR5 Nutter

[alan atkinson]

That's what I thought, although I guess that car was the 150bhp model.

 

 

Well I was extrapolating a bit.

The 104hp 2xZS cars tested around 10.5s, and the 150hp PIs at about 8.5s 0-60 (Autocar got one to do it in 8.2 apparently).

I figured a 125 would be about halfway - I don't have numbers for that one!

[Bald Rick]

Performance figures for all four TR6 models are quoted on the Regiser main website.

 

Tony

[88V8]

One odd thing you might look at - remove the airbox and one of the tubes, look down the throttle body while someone presses the accelerator. Does the butterfly open fully ?

The throttle stop is a high-tech bolt and locknut on the underside of the accelerator pedal. It works by hitting the floor. If you have thick or rumpled carpets, or overmats, or the stop is simply misadjusted, the throttles could be far from fully opening. How do I know that...

 

Ivor

[slimone]

 

Have a 73 myself, found same results as your self, carried compression test average 150 psi, also using 1pt oil per 500mls. engine overhaul in progress, plus ME changed for unleaded/new injectors.Halfords for tester. Hope this helps. Slimone

[smizgals]

Thanks for your help here Ivor will make contact with both

 

 

I can recommend the Hydrotechnik kit. They are also near you in Nottingham. A good price, especially when excluding shipment.

 

Stan

Edited February 24, 2010 by smizgals

[Yorkkie]

One odd thing you might look at - remove the airbox and one of the tubes, look down the throttle body while someone presses the accelerator. Does the butterfly open fully ?

The throttle stop is a high-tech bolt and locknut on the underside of the accelerator pedal. It works by hitting the floor. If you have thick or rumpled carpets, or overmats, or the stop is simply misadjusted, the throttles could be far from fully opening. How do I know that...

 

Ivor

 

 

 

I had exactly the same issue, it was the throttle cable outer moving with respect to the bulkhead. Also adjusted stops and now a totally different car. (well still a TR6 really)

 

Andy

Edited February 25, 2010 by Yorkkie

[jean]

If I remember well the CP TR6PI was rated, when I bought it in 73, on the Continent at 143hp compared to the 125 of the CR There is more than one way to measure power, maybe only a question if you want to sell or buy

 

So there should not be a huge difference in accelleration between a CP and a CR