Racing TC on std carb?

Competition engines and 'live' projects only. Good photos to illustrate your post are expected.
Post Reply
nickp
Posts: 54
Joined: October 23rd, 2007, 8:42 pm
Location: Barnsley, South Yorks. UK (A)
Contact:

Racing TC on std carb?

Post by nickp »

Hi Guy,

Someone I know races a 2.0 TC equipped car in a race series where all the cars are currently limited by using their original fuel delivery system. Unfortunately, his car came equipped with a single twin choke down-draft weber. Other cars in this upto 2.0 class came equipped with multiple carb setups, so their tuning potential is much greater. Probably the quickest of which are the Lotus 907 engined cars. His engine's currently std and he's reluctant to spend any time / money on it as he think's it'll always be held back by the carb set-up, which he has a fair point. I know his TC is never going to hit the headline BHP figures of these other multi carb equipped engines but was wondering if he could build a high torque engine rather than a screamer? He may get away with changing to a bigger twin choke carb, like maybe a 38DGAS which should help matters. I was thinking a good raise in CR (maybe 10.5 or 11:1) some head work and some mild-ish cams. What sort of increase do you think could be theoretically achieved with the single carb still on there?

Thanks in advance,
Nick
nickp
Posts: 54
Joined: October 23rd, 2007, 8:42 pm
Location: Barnsley, South Yorks. UK (A)
Contact:

Re: Racing TC on std carb?

Post by nickp »

Well, there's a 38DGAS on its way now. I think he's going to get it on there and see how it goes on the std engine to start with. Then possibly look into some engine mods to see how far he can take it with this carb.
His current engine is 120bhp with 2 x 34mm chokes and the new carb will have 2 x 38mm chokes.

Any thoughts Guy?
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: Racing TC on std carb?

Post by Guy Croft »

Is this about HSCC 70s roadsports?

G
nickp
Posts: 54
Joined: October 23rd, 2007, 8:42 pm
Location: Barnsley, South Yorks. UK (A)
Contact:

Re: Racing TC on std carb?

Post by nickp »

Yes, that's the series he's been running in. Although he's considering a change due to this carb restriction and may even end up with twin DCNFs in another series.
So, theoretically, what do you think a 2 x 38mm choked downdraft weber could be capable of on a well sorted TC?

Nick
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: Racing TC on std carb?

Post by Guy Croft »

mmm, will comment substatively on that later on.

But as far as I know the Lotus cars are (literally) in a class of their own being glassfibre bodied. The only steel shell two liter class units I can think of with twin carbs are the Ford Escort RS2000 and the Fiat Strada 13TC. I would not personally leave that series over the carb type. I think I got my facts right, client Graham Hall was kindly briefing me on this last Saturday.

http://www.hscc.org.uk/resources/70s%20 ... 202012.pdf

The club have kindly relaxed the current 2012 regs at my request (on grounds of OE part availability), thanks to Ralph Harwood-Penn for taking it up at Committee level. The following over and above the regs (see link) are now legal:

1. Race rods
2. Race pistons (to standard CR I understand - though CR issue may change).
3. Non-original bearings.


G
nickp
Posts: 54
Joined: October 23rd, 2007, 8:42 pm
Location: Barnsley, South Yorks. UK (A)
Contact:

Re: Racing TC on std carb?

Post by nickp »

TBH Guy I'm not that familiar with the series as yet and only started dicussing it with him the other day, and yes you probably have got your facts right. I think I might go and take a look at the meeting in August when they come up north to Croft.

Surely the 130TC is an 80's car isn't it? And didn't the RS2000 only have its twin downdrafts (IDFs?) for homologation purposes? Is that valid also then?
WhizzMan
Posts: 459
Joined: August 13th, 2010, 8:05 pm
Location: Amsterdam, the Netherlands

Re: Racing TC on std carb?

Post by WhizzMan »

Guy Croft wrote: The only steel shell two liter class units I can think of with twin carbs are the Ford Escort RS2000 and the Fiat Strada 13TC.
After reading the regulations for this racing class, I believe that the RS2000 may actually be classified as a "special racing version" and not be allowed to race in this class, just like the BMW2002Tii. I'm not sure, I guess it has to be determined by the people that are sanctioning the cars. However, The Alfa Romeo Giulia Sprint GT Veloce 1750 and later 2000 could possibly apply for the class D? Those have 2 double barrel 40mm carbs and the GTa racing version would make certain that they are the "regular" version and not the racing super light non-regulatory car. If not that car, an Alfa Romeo Berlina 2000 would most certainly be a competitor in this class, with the same engine and two double barrel carbs. Looking at the regulations, you would probably be able to get a good BHP out of an Alfa 8V Nord engine with 34mm chokes for certain, possibly even over 160.
Book #348
nickp
Posts: 54
Joined: October 23rd, 2007, 8:42 pm
Location: Barnsley, South Yorks. UK (A)
Contact:

Re: Racing TC on std carb?

Post by nickp »

Seems the Jensen Healey is steel bodied, always thought these were fibreglass. So they're the thing to beat with their 2ltr 16v Lotus engine.

I think it's a bit strange that cars running a single carb aren't allowed to modify or upgrade to a similar setup when running in a class where many of the others are running multi carb setups. Surely other competitors running their twin 40 sidedrafts wouldn't complain if someone turned up with a slightly bigger single twin choke would they? yes probably I guess.
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: Racing TC on std carb?

Post by Guy Croft »

some good observations there members, well done,

G
WhizzMan
Posts: 459
Joined: August 13th, 2010, 8:05 pm
Location: Amsterdam, the Netherlands

Re: Racing TC on std carb?

Post by WhizzMan »

I believe that the object of this class is not close racing, but racing as close to unmodified cars as safety permits. If that would put some types of cars in a disadvantage, they would probably put them in their own category if enough showed up to warrant that. No matter what you do, if you are going to race different types of cars, regulations will always favor one or the other under certain circumstances.
Book #348
Post Reply

Who is online

Users browsing this forum: No registered users and 33 guests