Replacing Automatic Choke with Manual Choke

[GeoSTI]

Ladies and Gentlemen,

My friend and I are prepping a 1979 Triumph TR7 for ITB racing and have come across an issue. The automatic choke fitted to the later TR7 model years is prone to failure and on our car has failed. Would it be permissible to replace the automatic choke with a manual choke? The GCR only touches on removal of the choke system, and I would expect the answer to be no based on the "all other components must remain stock" rule, but I'd like clarification.

Best,
GeoSTI

[CRallo]

Did any TR7's come with a manual choke?

[Streetwise guy]

I'm sure the early ones were manual choke, and failing that, How about leaving the components, but disabling the enrichment by locking it in the lean position?

[JeffYoung]

Woohoo, an ITB TR7!

I run a TR8 in ITS. Basically the same carbs (although I've now moved to injection).

FIrst off, ditch the carbs and go injection! No matter what any tells you about how "problematic" the Bosch L-Jet with the Lucas computer is, ditch it, go with the individual runner plenum and get a Megasquirt.

But I digress. To answer your specific question, all TR7s are on the same spec line. The 75 and 76 cars came with a manual choke (I actually had a 75) and thus putting on the manual is legal.

HOwever, you really don't need it and I'd just ditch it. The car will start in most ambient temps over 50 degress without it, and you can just use starting fluid below that.

[Russ Myers]

What he said. just remove the choke assembly. car will start without it. you will be warmed up enough just driving to the grid.

Russ

[CRallo]

What he said. just remove the choke assembly. car will start without it. you will be warmed up enough just driving to the grid.

Russ

Or that, it was late and I wasn't thinking outside the box...

[joeg]

Put a Weber on it.

[JeffYoung]

I don't think that is allowed on the 7 -- has dual carbs.

[jumbojimbo]

snip...

But I digress. To answer your specific question, all TR7s are on the same spec line. The 75 and 76 cars came with a manual choke (I actually had a 75) and thus putting on the manual is legal.

...snip

I think the question is answered, so I'm not really highjacking the thread I hope...at least not as badly as JoeG did.

Wait, doesn't this violate the rule about creating a model? I know this isn't a matter of using DX parts on an IX or coupe parts on a hatchback, but doesn't the same rule apply between years? IE, if he enters as a 77 TR7, doesn't it have to have all 77 parts and not some 77 and some 75?

[JeffYoung]

No, update backdate. All on the same spec line so if he takes the carbs from the 75 and puts them on the 78 or whatever, he is good to go.

BUT -- the rule specifically allows the removal of the chokes which is all he really needs to do.

[joeg]

...well put two Webers on it!