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Front intake & rear spoiler

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paulheritage
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Front intake & rear spoiler

Postby paulheritage » 13 Nov 2013 23:04

Not seen much mention of this on the forum but been thinking about it for a while.

<b><u>Front intake</u></b>
It is important to get cold air into the air filters, and hot air out. I've got a TR7V8 FHC and looking at options to get the airflow through. Already cut out some of the front bumper and have a rally front spoiler fitted, but also want to add a bonnet scoop. Should this be forward facing (forced) or rear facing (by pressure) ? Notice the TR7 Le Mans seems to use rear facing?

Also read about the MGRV8 having inner front wing grills to inner wing and allowing the air pressure to pull hot air out of the engine bay. This seems interesting .

<u><b>Rear down force</b></u>
Again, looking at best options for medium speed sprints/hill climbs. I've read about the Group44 in America regarding the poor dynamics of the standard TR7 FHC and they added a huge rear lip with big down force and drag. The Le Mans cars seems to have a completely different wing (more aesthetically pleasing) but perhaps different body mods.

Anybody got any thoughts on adding stability/down force etc. to the TR7 FHC?

Cheers Paul,

1976 TR7 2.0 FHC, ACG 3115 - Java Green (on the road)
1976 TR7 2.0 FHC, ACG 2367 - Carmine Red (on the road)
1980 TR7V8 3.9 DHC, Orient Blue (on the road)
1977 TR7V8 4.0 FHC rally car, ACG 35005 - Tahiti Blue (complete, no MOT)

www.TR7.co.uk

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Maxwell
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Postby Maxwell » 13 Nov 2013 23:17

A topic covered in part on Bullet-Reloaded....

Maxwell


2.0 TR7 FHC \ Current
1.8 Mazda MX5 \ Current

FI Spyder
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Postby FI Spyder » 13 Nov 2013 23:43

By having your exhaust manifold/headers ceramic coated, it will cut the heat by 30% or more. The heat passes out (further back) the exhaust pipe rather than radiating into the engine bay. That will go a long way to keeping engine bay cool.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT
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paulheritage
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Postby paulheritage » 13 Nov 2013 23:49

The headers are wrapped (not coated), but due to the crowded engine bay looking at options, as well is rear spoilers.

Cheers Paul,

1976 TR7 2.0 FHC, ACG 3115 - Java Green (on the road)
1976 TR7 2.0 FHC, ACG 2367 - Carmine Red (on the road)
1980 TR7V8 3.9 DHC, Orient Blue (on the road)
1977 TR7V8 4.0 FHC rally car, ACG 35005 - Tahiti Blue (complete, no MOT)

www.TR7.co.uk

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Hasbeen
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Postby Hasbeen » 14 Nov 2013 01:17

Paul I'm not sure if much of this works, except at higher speeds. How fast are your hill climbs?

We put a front spoiler, [a copy of a UK rally one], & added a sheet of tin from it to the bottom of the radiator. We had a much wider 4 core radiator, then closed off the sides & top of it pretty well. It had 2 by 16" fans, 1 front & 1 back of the radiator.

The car was virtually unusable in city traffic in our 30+C summers, but could handle country runs, in similar heat, driven hard, even with the air conditioning running. I spent a fortune in 5 years just trying to get it able to drive into town.

We discussed with the owner a 4.6L tuned TR8 in Darwin, [hot northern Oz]. He has twin scoops let into the nose/headlight panel. We liked this idea, [& they looked OK in photos], as it adds air to the top of the radiator, which is a dead area. Like our spoiler, this worked well at 80Km/H & above, but did not do much in town.

I did think about rear facing bonnet scoops, but more to allow hot air to escape. I figured a large part of the problem is getting rid of hot engine bay air. There is not much space for it to flow out.

I also thought about inner guard vents, but as I could not decide what the air Patten might be in the wheel arch, was not sure if they would be a help or hindrance.

My son then went mad. He fitted a much bigger inlet system & throttle bodies, a new Haltech computer controlling injection & a new ignition system, & much bigger injectors. With an extra 70 odd BHP I expected it to cook itself as we drove out the gate. It tried, but we beat it.

This time we went driving with the laptop connected. Rather than tuning the top end, the boy started richening the mixture at small throttle openings, low revs, [around 1200 to 1600 RPM] where the things runs in traffic.

This worked wonders. By the end of an hour we could cruise around the city, cool in air conditioned comfort, with a cool engine as well. It really was amazing when opening the bonnet stopped in town. Previously the hot air almost took your breath away. Now it was not much different to some nice little Mazda or such.

We decided all our overheating was due to running very lean at low revs, small throttle openings, & nothing to do with high end output.

Give it some thought, it worked for us.

Hasbeen

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Postby FI Spyder » 14 Nov 2013 13:49

I can't see venting the inner fenders doing anything. There are scoops from the front of the car that direct air from that high pressure area up over the wheel well (between the inner and outer fender) and down to the bottom rear of the front wheel well. I realized this when I sprayed a 50/50 mixture of waxoil and turpentine into the front scoops and you could see the mist coming out of the bottom holes (just ahead of the doors). This air circulation path is to dry out that area so the inner and outer fenders don't rust out (assuming the bottom holes aren't blocked with crude and it helps if you still have the angled plastic blocks that create a vacuum at speed to help suck the air out (see picture). As this area is under high (relatively) pressure you wouldn't gain anything by venting to this area.

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- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT
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