Can you help please lads
09-04-2009, 07:48 AM
#45
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Trade off between best aero & getting to the bottom with everything working within Spec. If we run with all the Power available circa 1050bhp we have enough Power to exceed 220 at brunters, however thats dream land we have to compromise on that. We will try to run 215 but only one uk based car has ever run faster over 1.5miles (215.7) & that had 8 litres
.This is getting hard lads we know of only 3 uk based cars that have exceeded 210 (we have done it unofficially) in 1.5miles .
09-04-2009, 10:12 AM
#47
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shame i'm so far away i could have taken a mold off all the front end and made it in polyprop to whatever style you wanted i have done a few for the speedway boys over here to keep the original look or with twin h/lights. i make them out of soft plastic so they don't break when they crash but can do them in any strenth
09-04-2009, 01:47 PM
#48
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Well its under way, will take bumper to be modded over weekend, have a double shot on the morettes, have a new part set on order minus inner lens although i dont know how long they will take to arrive so as a backup will pick-up a secondhand set tomorrow. Thanks for your help lads the twins will be doing the bumper.
Cheers Rod
Cheers Rod
09-04-2009, 08:41 PM
#52
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12-04-2009, 11:10 AM
#53
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There is another way you can cut and move back crossmember will go back about 4 inches to rad and then intercooler will fit behind standard bumper but i like the bumper on the car how it is looks different now to when nick owned it i will post a picture later
15-04-2009, 10:56 PM
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Rod, if you can, its better to make provision for better venting to allow higher flow through the cooler/rad.
Most inlet openings only need to be 75% (from memory and todays brain level is only set for a 9year old doing Disney) of the area of the core face so no point going OTT especially at 200+ which would guarantee the inlet is completely full but having to spill excess air giving unnecessary drag.
Low speed (short circuit) cars (in general) require larger inlets.
Most of the air exiting the coolers goes out through the engine bay underneath the car.
Unfortunately the wheel arches become a high pressure area with the tyres/wheels at around 3000rpm so not helping in letting air escape from underneath.
A front bumper splitter helps feed air into the bumper opening and also creates lower pressure under the car.
If you reduced the air pressure in the engine bay by adding bonnet venting this could also make the car feel more stable as would allow more air to go over / around the car rather than underneath it.
15-04-2009, 11:23 PM
#56
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Yes as its not very efficient to just increase the inlet size (bumper / grill opening) without increasing the outlet size.
Rod, if you can, its better to make provision for better venting to allow higher flow through the cooler/rad.
Most inlet openings only need to be 75% (from memory and todays brain level is only set for a 9year old doing Disney) of the area of the core face so no point going OTT especially at 200+ which would guarantee the inlet is completely full but having to spill excess air giving unnecessary drag.
Low speed (short circuit) cars (in general) require larger inlets.
Most of the air exiting the coolers goes out through the engine bay underneath the car.
Unfortunately the wheel arches become a high pressure area with the tyres/wheels at around 3000rpm so not helping in letting air escape from underneath.
A front bumper splitter helps feed air into the bumper opening and also creates lower pressure under the car.
If you reduced the air pressure in the engine bay by adding bonnet venting this could also make the car feel more stable as would allow more air to go over / around the car rather than underneath it.
Rod, if you can, its better to make provision for better venting to allow higher flow through the cooler/rad.
Most inlet openings only need to be 75% (from memory and todays brain level is only set for a 9year old doing Disney) of the area of the core face so no point going OTT especially at 200+ which would guarantee the inlet is completely full but having to spill excess air giving unnecessary drag.
Low speed (short circuit) cars (in general) require larger inlets.
Most of the air exiting the coolers goes out through the engine bay underneath the car.
Unfortunately the wheel arches become a high pressure area with the tyres/wheels at around 3000rpm so not helping in letting air escape from underneath.
A front bumper splitter helps feed air into the bumper opening and also creates lower pressure under the car.
If you reduced the air pressure in the engine bay by adding bonnet venting this could also make the car feel more stable as would allow more air to go over / around the car rather than underneath it.
17-04-2009, 05:18 PM
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If you wanted to allow more air to flow through the rad/cooler then on top of the bumper mods I would suggest additional bonnet vents.
There is adequate room for the air to exit through the engine bay underneath the car (even with a 4x4 undertray inplace) but thats not ideal for the car.
Also a lower engine bay temperature will normally lower the intake temperature, there is less heat soak into aluminium components like the intercooler (outlet end) and inlet manifold.
At the base of the windscreen is a high pressure area hence why they have the cabin air inlet / fan mounted under the scuttle grill (used as an inlet not a vent) as gets a good supply of fresh & the coolest air.
If you don't have A/C and want cool air for a road car then the bonnet (exit) vents shouldn't be placed in the middle of the bonnet, small vents won't make much difference but then if they were small they'd be no point putting them in.
I'd suggest putting exit vent louvers >500cm2 (10"sq min') near each side of the bonnet.
There is a low pressure area (ideal for venting) near the front edge of the bonnet due to the steep face (nose) of the car but this would draw hot air near where the inlet air filter would normally be. If this is the case put the vents towards the rear or better still insulate the air filter and supply with cool air from outside of the engine bay (ducted airboxes are best). Air filter intake from inside the wheel arch is perfect for top speed runs (clean air permitting) being a high pressure area (only when the wheels are at high rpm) but not ideal for track cars with 600 DegC front brakes, turbulence from the spinning wheels/tyres mixes the hot/cold air so no cool air present plus thicker cast iron discs radiate heat long after use.
The most effective way to vent the engine bay is to remove the rear bulkhead panel but the trailing edge of the bonnet would need a considerable upward lip to help scavenge air out. Plus you'd need to duct the cabin air supply from a new location to the fan (easy job).
The minimum inlet size for an intercooler/rad can be as little as 20% of the core area!
This is only possible with a very well designed car at high speed, at lower speed a fan would probably be required to obtain adequate cooling.
A thicker intercooler core will not require a larger inlet opening but will not be as efficient as a larger area / thinner core to lower charge air temp!
There is adequate room for the air to exit through the engine bay underneath the car (even with a 4x4 undertray inplace) but thats not ideal for the car.
Also a lower engine bay temperature will normally lower the intake temperature, there is less heat soak into aluminium components like the intercooler (outlet end) and inlet manifold.
At the base of the windscreen is a high pressure area hence why they have the cabin air inlet / fan mounted under the scuttle grill (used as an inlet not a vent) as gets a good supply of fresh & the coolest air.
If you don't have A/C and want cool air for a road car then the bonnet (exit) vents shouldn't be placed in the middle of the bonnet, small vents won't make much difference but then if they were small they'd be no point putting them in.
I'd suggest putting exit vent louvers >500cm2 (10"sq min') near each side of the bonnet.
There is a low pressure area (ideal for venting) near the front edge of the bonnet due to the steep face (nose) of the car but this would draw hot air near where the inlet air filter would normally be. If this is the case put the vents towards the rear or better still insulate the air filter and supply with cool air from outside of the engine bay (ducted airboxes are best). Air filter intake from inside the wheel arch is perfect for top speed runs (clean air permitting) being a high pressure area (only when the wheels are at high rpm) but not ideal for track cars with 600 DegC front brakes, turbulence from the spinning wheels/tyres mixes the hot/cold air so no cool air present plus thicker cast iron discs radiate heat long after use.
The most effective way to vent the engine bay is to remove the rear bulkhead panel but the trailing edge of the bonnet would need a considerable upward lip to help scavenge air out. Plus you'd need to duct the cabin air supply from a new location to the fan (easy job).
The minimum inlet size for an intercooler/rad can be as little as 20% of the core area!
This is only possible with a very well designed car at high speed, at lower speed a fan would probably be required to obtain adequate cooling.
A thicker intercooler core will not require a larger inlet opening but will not be as efficient as a larger area / thinner core to lower charge air temp!
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