tooquicktostop Posted July 14, 2008 Share Posted July 14, 2008 Could be the Do-Luck one? They are a lot more subtle than the TS ones Exterior: TRD rear spoiler with carbon insert, do-luck front, stillen skirts, top secret rear spats, do-luck rear diffuser, clear indicators all round, HIDs x2 sets (mains+fogs), terra side light bulbs, led rear bulbs Yep, just took this from UKrich garage, Do-luck diffuser, I need one Quote Link to comment Share on other sites More sharing options...
Angarak Posted July 14, 2008 Share Posted July 14, 2008 I think they're mostly for bling rather than true effect. As mentioned previously, one was ripped off at a trackday as it was no doubt acting as an air brake at serious speed. On another note, I think you'll have some clearance issues on speed humps with some of the ones posted (like the 1st pic in this thread). Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 14, 2008 Share Posted July 14, 2008 One of the last two Race Car Engineering magazines had a good article on rear diffuser design, the maximum effective angle was 10 degrees for the roof of the tunnel, and it needs to start a lot further forward, on a much lower car to be really effective. I'd say these add ons are mainly styling additions. Tony? Quote Link to comment Share on other sites More sharing options...
TLicense Posted July 17, 2008 Share Posted July 17, 2008 Sorry Jay, only just got around to replying. In general I would say leave well alone. At best you're going to create a car that has variable downforce with ride height. Fine if you live on a race circuit, not so good on HM highways. Imagine going into a corner with say, 500kg of downforce. You turn in to the limit of grip then you hit a bump which raises the ride height of the car and you lose 300kg of that downforce. Your next stop will be the hedgerow. However, the chances of actually getting the thing to generate decent downforce to start with is going to be quite slim without a good deal of aero analysis. Fitting a splitter may well give you a low pressure region underneath it, but is that now killing flow to another area of the car? If you fit just a diffuser, you may be able to get additional rear downforce from it, but it's going to be pitch sensitive and will most likely stall when you brake into a corner (which is when you're going to want it). There's an almost endless opportunity to cock things up, and a very small window of becoming a aerodynamic superstar! Quote Link to comment Share on other sites More sharing options...
Gaz Walker Posted July 17, 2008 Share Posted July 17, 2008 There's an almost endless opportunity to cock things up, and a very small window of becoming a aerodynamic superstar! Lovely quote Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 17, 2008 Share Posted July 17, 2008 Sorry Jay, only just got around to replying. In general I would say leave well alone. At best you're going to create a car that has variable downforce with ride height. Fine if you live on a race circuit, not so good on HM highways. Imagine going into a corner with say, 500kg of downforce. You turn in to the limit of grip then you hit a bump which raises the ride height of the car and you lose 300kg of that downforce. Your next stop will be the hedgerow. However, the chances of actually getting the thing to generate decent downforce to start with is going to be quite slim without a good deal of aero analysis. Fitting a splitter may well give you a low pressure region underneath it, but is that now killing flow to another area of the car? If you fit just a diffuser, you may be able to get additional rear downforce from it, but it's going to be pitch sensitive and will most likely stall when you brake into a corner (which is when you're going to want it). There's an almost endless opportunity to cock things up, and a very small window of becoming a aerodynamic superstar! Super post that. I think the majority of Jay's runs are going to be straightline/drag runs, would something like a flat underside aid his aero and increase stability? Quote Link to comment Share on other sites More sharing options...
TLicense Posted July 17, 2008 Share Posted July 17, 2008 Potentially yes. But getting it right will be quite difficult. The other problem is that whenever you find downforce, you will find drag. For drag racuing I wouldn't want to sacrifice the amount of drag you would gain for the potential gain in stability. As you point out, it's not like he's got any approaching corners to worry about! Plus I should imagine the car is going to be reasonbly stable anyway unless you throw in some manic driver inputs. Quote Link to comment Share on other sites More sharing options...
jevansio Posted July 17, 2008 Author Share Posted July 17, 2008 Many thanks for the reply Tony I think for the minute I'll just get hold of some OEM undertrays to replace the ones I've lost for the front & maybe get a diffuser (but for nothing other than show ) Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 17, 2008 Share Posted July 17, 2008 Oooh it's excess weight Jay! Quote Link to comment Share on other sites More sharing options...
bolarbag Posted July 17, 2008 Share Posted July 17, 2008 Would sealing the underside flat be beneficial? If you could seal the proporation of the underbody from firewall back would that create less drag? I was thinkin of getting a custom one made to the underside of the car, but if it woud be of no benefit then its not really worth the money, the chosen material would either be cf or aluminium, with the costs being similar, obviously weight differences favouring the cf Quote Link to comment Share on other sites More sharing options...
johnny g Posted July 17, 2008 Share Posted July 17, 2008 I was thinkin of getting a custom one made to the underside of the car I've got one for my MR2 - I've not tried it out yet, but people over there who use the cars for trackdays are saying that's a vast improvement. But, the MR2 is quite poor at 100+mph really, in comparison. Would a completely flat underside in Al create more drag? My understanding was that it would allow the air to pass through, with less turbulence, creating a low pressure area - obviously, the quantity of the downforce is unknown, but it might help? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 17, 2008 Share Posted July 17, 2008 Sealing the underside, flat or knobbly, may well see hugely raised diff and gearbox temps, and an attempt by the exhaust to set things alight. It will certainly affect engine temps as a lot of rad air exits down the tunnel and merges with the under car slipstream. on a 1/4 mile run you'd probablt get away with it, on a track day you almost certainly wouldn't. Quote Link to comment Share on other sites More sharing options...
TLicense Posted July 17, 2008 Share Posted July 17, 2008 You wouldn't get turbulant drag from the air hitting the components, so you would see a drag reduction there. But then you would get parasitic drag due to the downforce you would be generating. The net result "could" be a drag reduction or it "could" be a drag gain. Where the cross over point of one outweighing the other is anyones guess. Another thing to think about is the rolling resistance you would be adding. If you're creating 500kg of downforce, it's like having 1/5 tonne in the car with you. OK it's only going to be there at higher speeds, but if it was a drag race, you wouldn't want it period. Quote Link to comment Share on other sites More sharing options...
jevansio Posted July 17, 2008 Author Share Posted July 17, 2008 Oooh it's excess weight Jay! yeah I know, but it's CF so should weigh next to nothing (and it's at the back where weight is the least of my worries). Quote Link to comment Share on other sites More sharing options...
Gazboy Posted July 17, 2008 Share Posted July 17, 2008 If you flat bottom the car you run the risk of turning the entire car into an aerofoil, if you get the balance wrong you can flip over backwards like an Ultima a few years ago, and the Merc CLK's at Le Mans. This is what happened to JUN at Bonneville in their RX7. They didn't flat bottom the Akira Supra when they went back a few years later. Jay, in regards to Brunters, Supras need extra drag like a hole in the head, perhaps remove the wing and take off the front active spoiler instead? Quote Link to comment Share on other sites More sharing options...
jevansio Posted July 17, 2008 Author Share Posted July 17, 2008 If you flat bottom the car you run the risk of turning the entire car into an aerofoil, if you get the balance wrong you can flip over backwards like an Ultima a few years ago, and the Merc CLK's at Le Mans. This is what happened to JUN at Bonneville in their RX7. They didn't flat bottom the Akira Supra when they went back a few years later. Jay, in regards to Brunters, Supras need extra drag like a hole in the head, perhaps remove the wing and take off the front active spoiler instead? Hey Gaz, The front active spoiler is going very shortly (although I'm not sure if the RMM style front lip will be any better), next time I would defo be removing the spoiler (although next time I'll have a 4-Row & T51R setup pushing me that bit harder ) Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted July 17, 2008 Share Posted July 17, 2008 The front active spoiler is going very shortly If you want to get rid of your whole bumper can you let me know please mate? I'm bored of ruining my do luck Quote Link to comment Share on other sites More sharing options...
jevansio Posted July 17, 2008 Author Share Posted July 17, 2008 If you want to get rid of your whole bumper can you let me know please mate? I'm bored of ruining my do luck Sorry Gaz, it's just the OEM lower lip & UK lip that's going, I haven't found a front yet that I prefer over stock front bumper Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted July 17, 2008 Share Posted July 17, 2008 Sorry Gaz, it's just the OEM lower lip & UK lip that's going, I haven't found a front yet that I prefer over stock front bumper TBH I haven't either mate. Quote Link to comment Share on other sites More sharing options...
jevansio Posted July 17, 2008 Author Share Posted July 17, 2008 TBH I haven't either mate. I'm sure I saw a black facelift front for sale not too long ago in classifieds? Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted July 17, 2008 Share Posted July 17, 2008 I'm sure I saw a black facelift front for sale not too long ago in classifieds? I've only just begun looking to be honest fella, it's been playing on my mind for ages but I hit the do luck HARD in a field at Goodwood Festival of Speed and it's now a lot more broken. I'll have a look. Quote Link to comment Share on other sites More sharing options...
Gazboy Posted July 17, 2008 Share Posted July 17, 2008 Jay what is a 'UK lip'? I think a Bomex lip blended into your OEM bumper would look ace. Quote Link to comment Share on other sites More sharing options...
Mike B Posted July 17, 2008 Share Posted July 17, 2008 On the 3 sups i have had I have run 4 different bumpers and at 140mph I can feel the difference in stability. Veilside and stock were ok, the current Stillen makes the car feel light and wandery, but by far the best was do-luck.. feels planted to the road. Interesting reading tony's posts. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted July 17, 2008 Share Posted July 17, 2008 On the 3 sups i have had I have run 4 different bumpers and at 140mph I can feel the difference in stability. Veilside and stock were ok, the current Stillen makes the car feel light and wandery, but by far the best was do-luck.. feels planted to the road. Interesting reading tony's posts. Have you tried the stock/active spoiler option? If so, does it have an effect? Quote Link to comment Share on other sites More sharing options...
Gazboy Posted July 17, 2008 Share Posted July 17, 2008 Jay what is a 'UK lip'? Hello? Quote Link to comment Share on other sites More sharing options...
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