Its 1750mm wide which is the same width as the rear arches so it should fit down the drive fine, the only thing is because its a fair bit behind the car and high up i cant see it in my mirrors so since i can take the wing off in under 2mins i will probably take it off when pulling it out of drive for a while until i get used to it.
Also sorted out a trailer today which will be able to load the car on and off at race height(80-90mm) which is great news as i was a bit worried because of the front and rear overhangs
Yeh be great to catch up, been missing going up the cat and fiddle but didnt really want to go up in my volvo, not really the same thing!
Little update
Started making the brace for the turbo, there is 3 threaded holes on the block that we are going to bolt a plate to, off that will be a bar connected to the turbo, this will take some of the weight off the head as the manifold, turbo and downpipe add up to a fair bit of weight.
Finished the hangers for the exhaust, we are going to hang it off the wing uprights(the horizontal section is higher than the longeron) may aswell make use of them for something else.
Made an adapter plate for the throttlebody and ported the inlet out so its a better transition from round to rectangle
Bought and mocked my chargecooler, this seemed the simpliest solution, with the shortest pipework and gives me something to mount it off(again horizontal upright) It looks close to the tyre but is actually 10cm away so should be fine, especially when im running very hard springs.
This is a quick doodle of the layout so you can see how I have done it
Being happy with my design I started working out all the bracket components and silcone pipe lengths, some of you might be thinking about having a fixed chargecooler but a ‘rocking’ engine but i was going to add silcone inflated joiners to cover for that.
Anyway later one in the evening I sat and thought about Djwillmas car a bit more and what he had done mounting it underneath the inlet manifold, so I went back out there to see if I would do the same thing but have it standing upright(inlet/outlet pointing up) but due to the size of it, it wouldnt work, there would be noway I could get a pipe between the outlet and the throttle body without doing a massive load of angles and pipework.
So I placed the chargecooler ontop of the inlet manifold, and it seems the perfect solution, very very short pipe runs will help with throttle response, weight and keeping heat soak from the pipes, the engine cover fits and there will be no concerns about engine movement
Also in regards of my aero package, i contacted Simon Mcbeath to get his point of view on the car.
This was his response, the red font are his words
Hi Simon,
Im sure you get alot of messages everyday asking all sorts of questions so ill try and keep it relatively short, if you could add any thoughts to my aero package I would be most grateful.
I started reading info from yourself from Track Driver Magazine, then ive bought and read your book and started subscribing to Racecar Engineering, though I did start building the car before I bought your book so there might be a few bits that may not have followed the book.
Its a Series 1 Lotus Exige that I will be running in UK Time Attack Series next year.
Since I cannot afford a 500bhp audi/honda engine or the maintenance that will go with it, I decided to make up the laptime with higher apex speed and lateral G, so im running a 300bhp rover k series engine with a 700kg weight without driver, for reference im up against 600bhp/1000-1100kg cars.
The bit im stuck on is the rear diffuser and wing placement, now Time Attack is one of those rare motorsports where there are no aerodynamic limitations(like Pikes Peak), if you can dream it you can make it. I’m very familiar with TA, we have quite a few clients worldwide.
Your book mentions to run as steep an angle as you can get away with while keeping the air attached to maximise the flat floor area within the dimension restrictions…but what happens if you dont have the dimension restrictions, if we forget rear wing interaction is it better to run it longer and shallower to allow for the gradual air pressure dispertion.
Im running a fully flat underfloor the width of the rear tyres, with end plates and skirts the full length so most air that gets under the splitter should make it to the rear of the car.
My diffuser is actually about 1 metre long and full adjustable from 3* up to 10* will the length give me any advantage?
Am I best just keeping it at the usual limit of 7* or will I gain an aerodynamic advantage by running it at a steeper angle, just film from behind to check tuffs are still pointing up to check attachment?My personal view is that a diffuser can be steeper than this on your type of car but it should only extend a short distance out at the rear. The reason for this is that you also get low pressure acting on the roof a diffuser that juts into the wake area, which will create some positive lift. There’s no arguing that bigger diffuser volume drives the underfloor harder to get more downforce there, but there must be a trade off and I don’t advise going as far back as you have gone.
Also since the lotus chassis doesnt have much front overhang it makes it more difficult to create decent levels of front downforce so what I have done for the splitter is have it extend from the front of the car buy 200mm, but rather than following the shape of the front clam(curved) maintaining 200mm, I have made the front square to maximise surface area, added 60mm end plates and large canards with endplates(the plates arnt shown) I didnt go any higher on the end plates on the splitter for fear of it negatively interacting with the canards. The front end kit looks aggressive, as it needs to be to balance a dual element rear wing, but I can’t see any major flaws from the photos.
I am going to cut out a big rectangle on top of the front arch to let any high pressure out and try and I have some space carbon angle to glue infront of it to allow the high pressure air to escape which should help against lift, I was going to try and make multple louvres along the length of the hole but I notice the LMP1 cars just have an open rectangle, this might be regs but wasnt sure.Louvre the cutouts so air can’t get in from the front.
Would you agree that im going along the right path(front wise)?yes
And the final thing Im wondering about is, your book pretty much says to put the wing as high and as far back as possible to get cleaner air to maximise downforce or the need to run less wing to reduce drag while still maintaining the same level of downforce, when you put the rear wing further back from the rear axle it creates a leverage that also lifts the front end up.
Now if I cannot create enough frontal downforce to be able to make proper use of the wing, would moving the rear wing further forward towards the rear axle allow more downforce to be applied to the rear wheels without adding excessive front end lift, Ive made the uprights a very simple design so i can easily slide the wing forwards and rearwards to find the best solution, once its finalised ill make some better ones without the 90* angle.It’s all a trade off – yes, further forwards means less unloading at the front, and also less Df at the rear tyres for the same wing setting. But this is also about getting the wing off or high enough above the rear deck so it doesn’t suck upwards on that.By eyeballing your photos I suspect you will have too much rear wing to be able to get a balance as things stand.
ie say I get 100kg of front downforce at 100mph and 200kg of rear, but the rear wing lifts the front up by 50kg, then moving the rear wing forward 15cm and turning the wing up a little to maintain the 200kg of downforce and only have 20kg of front lift…or does it not work that way?
Sorry for all the questions and thanks in advance for taking the time to read this, any information you can provide and thoughts on my project would be most grateful as i can imagine your a busy man but I didnt know who else to turn to as to save wasting any of your time.
From what I can read into that is that I should shorten my diffuser and bring my wing further forward to stop the leaverage effect which was discussed in this thread in detail ,
But from what he says I think that the larger diffuser will drive the underbody harder, hence create more downforce at the throat so providing more front downforce at the expense of the rear because my throat is fairly forward with the rake im running, now that actually might be a good thing as my rear wing will give me more downforce than I will ever need and its the front that needs the work, so trying the longer diffuser and more wing instead would give more front downforce compared to shortening it and running less wing angle.
Moving the wing forward 15cm seems the best thing to do to stop leverage effect, though its important to make sure the full underside of the wing is either high enough to stop it pulling on the clam or back far enough to stop the same effect, at 15cm im a of centremetre from overlap.
Made a start on helping reduce high pressure area in the front clam, there are 3 things to do, the first is to remove the lower sill extensions as they are working like little parachutes not letting the air out and generally catching bricks.
You can see them as the little black panels on the bottom right hand side
So off they came but that meant I had nothing to hold the rear of the clam from flapping, so I made some carbon extension plates to bolt everything together.
Also we finished up the turbo setup today, bolted it all onto the jig to check over everything before its all bolted to the car tomorrow night.
Im pretty happy with it all, seems to do everything we want, only extra thing we need to make is a turbo brace which will bolt from the inlet manifold to the turbo to help take pressure off the head. We will bolt a couple of rose joints from the upper inlet with bars connecting to the side of the turbo.
We have looked at a lower manifold mount as below but havent made the final decision on this as it potentially can cause issues by the metal pipe expanding putting vertical pressure on the manifold rather than taking the weight of the manifold off the head
We have had to make a few amendments on the oil drain to clear the alternator as it was a bit tight, so once thats done we can start the engine, getting a little bit excited now, be interesting to hear what it will sound like, then I can get it out of my garage and over to dan websters to sort the gearbox and suspension out.
Heres how it looks at the moment
Now a famous person once said power is nothing without control so I knew I needed to get a wideband in there, now in the past ive always ran innovate gear but alot of people have been recommending AEM as a much better unit so since they are the same price I decided to give it a go.
Spent some time making a carbon plate so house my battery cut off, wideband gauge and also left room for a oil temp/pressure dual gauge ill stick in it next year. So im hoping tomorrow if we havent got galeforce winds again im going to run the wires from the lambda boss to the gauge.
Fingers crossed the next post will be the usual engine running youtube video and if its not raining/dark me getting it out onto the street.
As long as it doesnt happen to be on the same day as a Time Attack and I have the funds then I dont see why not.
The plan is to have the car on the dyno at the end of january though after chatting to TDI i might have 2 maps, say 8psi for trackdays and 15psi for time attack, though the final power output will determine the boost pressure I run.
well the original plan was to go to dave at emerald to map it since its his ecu and he knows k series really well, but randy suggested sam might be better has he has alot of experience with k series/emerald and alot more turbo experience that dave.
Now ill have a wideband in it ill probably do a bit of part throttle, idle and cruise bits myself so that its a bit more drivable for getting around, ill leave the WOT to him as he will have det cans and will be able to hear it alot better than I can, if the emerald had a reliable knock sensor input I would probably have a go at tuning it myself(was a bit spoilt withmy old apexi power fc I think)
to be honest you’ll be wasting your time with the mid range stuff, the TDI dyno is fantastic at being able to hold a hub speed whatever the throttle angle, so they can set it up quick
Oh and it’s likely he’ll rescale your rpm points anyway to better use the tables.
ah right, ill probably just do the idle and maybe a bit of the motorway cruise so im not running super rich while im driving down to him as its a fair drive.
Thats just reminded me, I need to order from Vauxhall VXR injectors when I get paid so I know ive got enough fueling capacity for when its on the dyno
One thing you might want to think about is fitting a brace on the exhaust, just after it leaves the turbo that rigidly holds this in place, braced to the engine block and / or head. Most of the issues I used to have was with trying to get the turbo to stay on and fitting this post turbo brace to the downpipe, basically took all of the strain off the turbo. If I had a pound for every stretched turbo bolt I had!!!
We had to modify the oil drain to clear the alternator as it was touching, so finished that tonight and got some heat wrap, put it around the drain just to help against the heat as it comes past the manifold
Also got some heat wrap to do my fuel lines and anything else close to the exhaust system and if theres any left ill put some on my bulkhead around the turbo area
Also my dash panels we looking a bit of a mess with bits where the paint had chipped away, its been like that since I had the vehicle and has been bugging me like mad, so I took the panels in and using boiling water peeled all it all away back to bare ali, took quite a while to do.
Then wrapped them in 3M carbon fibre wrap, the idea pinched from another member on here
At the end of next season ill probably strip down the enter dash and make real carbon pieces for everything to save weight and make the dash look more uniform as at the moment I have 3 different types of carbon weave on my dash.
And fitted them back on
Also plumbed everything back in engine wise, just need to put a new oil filter on and fill with oil and ill be starting it up tomorrow, very excited!
Surely its trailer time 
