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Triumph TR4 vs Super 7 battle - NJMP (USA)


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#1 hoffman900

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Posted 31 July 2018 - 12:59 AM

Thought you guys might enjoy this...

 

Saturday race:

https://youtu.be/THsHEiI1LzU

 

Drying conditions. TR4 fast lap: 1:36.560, Lotus fast lap: 1:35.632 

 

Sunday race:

https://youtu.be/-VgCi4kJJk0

 

Dry condtions. TR4 fast lap: 1:34:365 , Lotus fast lap: 1.34.175. Average speed ~86mph. Both turn their fastest lap on lap 4 (5:20 in) 

 

In-car from the Lotus..

 

 

Enjoy! 


Edited by hoffman900, 31 July 2018 - 01:09 AM.

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#2 Hamish

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Posted 31 July 2018 - 02:27 AM

Great filming.
Thanks for sharing.

Anyone know the specification of the TR4 ?
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#3 Motorsport Mickey

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Posted 31 July 2018 - 08:38 AM

Great filming.
Thanks for sharing.
Anyone know the specification of the TR4 ?

Great filming.
Thanks for sharing.
Anyone know the specification of the TR4 ?


Take note of the revs used and it's range, that's one seriously torquey engine, you can tell by the engine note it's not being extended into "starship" range for the power.

Mick Richards
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#4 Lebro

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Posted 31 July 2018 - 08:49 AM

Between 5k & 6.3K when the red light comes on.

 

Bob.


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#5 TR NIALL

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Posted 31 July 2018 - 11:00 AM

5sp Gearbox?
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#6 hoffman900

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Posted 31 July 2018 - 11:22 AM

Hey guys, he's shifting at 6500 (except the starts), but the shift light was creeping down. Makes power and will spin up to 7000, but well only do that in anger (and power typically isnt the problem).

Rules here in the States are based off old SCCA regs. So .040 overbore, no stroker cranks, no dry sumps, and no crank trigger ignition. Just about everything else is free and we can get 112 octane leaded race fuel here no problem, so compression ratios are higher than you see in Europe.

5spds are allowed in vehicles that came with overdrive stock, but has to be production based (internals are free). A close ratio dog box Triumph transmission with an overdrive would be just as fast, but less reliable.

Car has to weigh 2150lbs w/o driver. The Lotus is 1250lbs, but hes 150lbs over the rules allowed 1100lbs.

Pictures here: www.the71crowd.com

Edited by hoffman900, 31 July 2018 - 11:48 AM.

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#7 Motorsport Mickey

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Posted 31 July 2018 - 01:42 PM

Hi there Hoffy,

Is the +40 on 86mm or 87mm ?

if on 87mm +40 with an offset head it will breath like an 89mm anyway. Does the non stroked crank mean it has to have a standard Triumph crank non billet ? Or can you have a billet crank but to stand regs ? or can you stroke a standard crank ?

Regards
Mick Richards
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#8 hoffman900

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Posted 31 July 2018 - 02:02 PM

Hey Mick,

.040 on the 86mm, so 87mm is what everyone runs. I think most anyone serious is offsetting the head to at least some degree.

Standard stroke dimensions - all the serious racers are running ghost main billet cranks. Bearing sizes, etc. are all free.

Edited by hoffman900, 31 July 2018 - 02:02 PM.

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#9 jellison

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Posted 09 August 2018 - 08:55 PM

Car look like a well sorted and v.fast package.

Pity it has to be that heavy, thats 975kg!
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#10 hoffman900

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Posted 10 August 2018 - 11:21 AM

Hah. Rules are rules. Do you still have your TR4?
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#11 kevin bryant

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Posted 11 August 2018 - 07:37 AM

Not viewed sunday yet. but shouldn't the TR have held position and stayed behind the Lotus until after the waved flag?

kev


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#12 hoffman900

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Posted 11 August 2018 - 10:36 AM

At the start? The grids are set side-by-side. Green flag is out, passing is allowed. Pole only gets inside track position for turn 1, we were qualified on pole (up to 8s/lap at one point) and pulled in early. The Lotus set a time a little faster on the last lap of the session. It didnt matter as we knew (and told him - very friendly guy) that the TR was going to go sailing by at the start. The Lotus played the start better on Sunday, but a fast in a straight line Datsun (~225bhp from a 2L 510 engine) ran up the inside and foiled his plans.
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#13 jellison

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Posted 14 August 2018 - 11:40 AM

Hah. Rules are rules. Do you still have your TR4?

of course. Never sell a car.
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