Scruffythefirst

Ha ha, body is still in the moulds in harlow. I'll pick it up when I get back from holand, probably thursday morning. New chassis is getting there, as soon as I've got a few extra bits I'll whip the engine in temporarily and get all the bodywork on so I can measure up for a custom radiator and weld any appropriate brackets on.

Well finally got out of the hell that was sitting in the pub all day everyday getting paid and managed to get home. Unfortunaley 2 months of paperwork has caught up with me and I've not done much. A few of the shiny bits have turned up though. Steering column dismantled to fit better bearings and or bronze bushes to replace the standard Ford crap with something with less slop. Billet flywheel and hydraulic clutch slave have arrived Fitted the clutch cylinder which replaces the nose of the box, pretty easy, although I'm not sure if I need to shim the input shaft bearing, I had brief read of the workshop manual but didn't bother measure it. Might have to take it apart again... New chassis should be ready by the end of the week, but I'm running out of time (7 weeks and counting) and I've done nothing to get ready for its arrival. Oh well, I'll see how close I get and if I have to borrow dad's MX5 for the LWTLM european tour!

Which corner, I seem to remeber several :shock:

Its cheaper to buy a mainstream car like a westfield or dax ready built, but if you enjoy the build then yes I'd reccomend it. I've built 2 now, the dax was infinitley more complicated than the westfield XI but both were very rewarding and satisfying to see on the road. Only problem is they are never finished and there is always something to upgrade. I'd reccomend going for a quality kit though, some of the locosts are a bit ropey, where as Dax, Westfield, Fisher (fury) are pretty good.

Embarrasingly enough I was on my way to a high performance driver training day, probably the reason I wasn't driving it like I stole it.

Front left corner took most of it, it looks worse than it is but couple of chassis tubes are bent.

Bugger, a bit too Icy still even on the M11.

The ecu controlls the anti lag when you request it via a switch on the dash, but the ecu can turn it off if the EGT's get too high, a good saftey feature to have if the ecu supports it, stops you gettting carried away and melting stuff.

Looks like its got the right sort of bits in it. GT28 in a slightly bigger trim than the RS (disco potato) should see you right. If you just use the antilag occasionally (and launch control etc) then you can probably get away without too many mods, although having it locked out by an EGT probe would be good if your ecu can do it. Don't forget you can get the GT series turbo's with normal journal cores which means you get the faster spool from the improved housings and impellors in a core you can re-build for a very marginal increase in spool / lag. I'll see if i can dig out the exact trim i'll be going for when I upgrade.

What turbo do you currently have and whats the engine spec. What Ecu? Mountune do all the bits you'll need for ALS although they're very expensive. Alternatively, port your ISCV as much as possbile and see how much effect it has, you'll have to get the ecu set up as it can cause idle problems without using a seperate valve. If you want to use anti lag all the time, get a turbo designed to handle it. (bear in mind proper antilag gets expensive when you consider just a maram 247 shaft is £700) The bottom line is really, how much power do you want / can your bottom end handle and are you prepared to make other mods to suit the turbo. (these are ballpark figures, get someone who knows your engine to spec the exact turbo, trim and housings etc) GT40 external gate 500-stupid bhp no ALS GT30 internal /external gate for 400-550bhp but forget antilag T4 should do 500Bhp but will be laggy as hell. or if you want some sensible numbers, a maram shaft T34 for 300-400bhp GT28RS for 300-360ish other trim GT28's for a little more (forget antilag) Wouldn't hurt to get everything ceramic coated as anti lag will cook everything in your engine bay, although ceramic coating the manifold can lead to heat problems for the turbo and valves. Might not be a bad idea to lockwire all your turbo and manifold nuts as it has a habit of loosening them pretty quick.

Well the poeople who build my turbo's say no need. I'll stick with them as they're the ones upholding my warrenty.

What a load of rubbish, surge has nothing to do with dump valves. Surge occurs when the compressor is too big for the turbine, it generated a massive boost spike as it comes on boost, the ecu responds by opening the wastegate and boost drops off as the huge compressor stalls, ecu shuts wastegate turbo generates big boost spike and so on. Anti surge housings are a compromise as they slow the turbo's ability to spool by bleeding air from the edge of the compressor housing back into the inlet. Much better to get a properly specced turbo in the first place if you ask me. All the turbo manufacturers I've spoken to say no need to run a BOV unless running a turbo way off its compressor map and shaft speed, and in that case you might as well get a different turbo. The only damage its likely to do is to the shaft, and the experts seem to think a BOV can excacerbate the shaft loadings in some cases. OEM's fitted recirculating BOV purely to get rid of the noise.

The more air you flow, the more fuel you can burn, the more power you make. Pressure is just flow thats stacked up in front of a restriction (in this case the engine) not going anywhere, making no power. To be honest, I wouldn't bother with anti lag, just the launch control and full throttle gear shift - plenty of silly poping and banging, flames and broken gearboxes. If you drive smoothly and progressively, anticipating the road ahead with a correctly specced turbo it shouldn't be too bad on the road. Anti lag simply won't get through track day noise regs most of the time. A lot of people confuse spool with lag, anti lag won't make the turbo spool any faster. No real idea on what the internals of your engine can cope with, but its most definately torque (and revs) that will snap rods (torque is usually a direct product of boost pressure). If you intent on running anti lag, I'd get a maram shaft T34 in a suitable trim, but TBH, speak to an expert cos unless you've got an accurate idea of VE and mass air flow, all the compressor maps in the world won't help you. GT28RS is a popular turbo good for around 300ish, a slightly different trim version GT28 gets about 360ish. The more revs you can use, the bigger the engine and the better the VE will mean you can spool a bigger turbo in time to use the power.

As does french tunnels 8)

Ohhh My ears are burning :oops: :oops: Anti lag (ALS) is a way of keeping the exhaust turbine of a turbo spinning against the resistance of a closed throttle plate and lack of exhaust energy. There are several versions of anti lag but I'm not going to get into EGR anti lag as its complicated and mountune want £3K for it. The normal rally car ALS works by dumping fuel into the engine with air that is bypassed round the closed throttle plate, this would normally produce lots of power (simmilar to being at half throttle or therabouts) which is bloody dangerous if your trying to brake for a corner as the engine is pushing you forwards. The key to anti lag is that the ignition timing is retarded after TDC - (30deg ATDC rings a bell) so the piston is already on its downstroke so by the time combustion gets going the exhaust valve is opening and your not getting any effective work done into the crank. All this energy generated is blown out into the exhaust where it is rapidly expanding and very hot - ideal for keeping the turbine spinning. This unfortuately leads to very hot exhaust valves, turbine components and exhausts. As the turbine is spinning when the throttle is closed you are generating boost with the throttle closed, this means you will have boost available instantly you open the throttle again, plus the turbo is already at full speed, meaning no lag. This won't help so much if you drop below the boost threshold rpm of the engine though, as although you will have boost when you re-apply the throttle, the exhaust gas energy will be lower than it would be at high rpm and the turbine speed can drop. You can have various levels of anti lag, obviously the rally car boys run the maximum they can, meaning they produce full, if not more boost than they do at full throttle (air restrictors, lack of flow against a closed throttle etc). These need big air bypass valves, and generate massive temperatures. Maram 247 shafts are more heat resistant, ceramic coated turbine blades, turbo housings, exhausts and valves (often sodium filled) help manage the heat, but on a rally car it doesn't matter too much as turbo's get rebuilt after every event or changed during it. Milder anti lag is still a benifit, and still particularly antisocial and can be done with a modified idle valve (to produce more flow), but it needs suitable software in the ecu. Some tuners have managed to retro engineer it into standard cossie ECU's, but pukka ALS is usualy the preserve of high end aftermarket ecu's like pectel T6. There is another type of anti lag that works in the same way but doesn't require any modifcations to the idle valve, this is usually used for launch control and full throttle shift on turbo cars. If you hold down the clutch and the throttle fully open you'd normally just rev the car into the rev limiter and it would sit there banging its tits off. If the ecu retards the ignition so that fuel is ignited in the same way as anti lag you can produce boost without producing any torque on the crank. So if your accelerating and change gear with your right foot flat on the floor, a switch on the clutch kicks in the full throttle shift which retards the ignition enough to allow the engine to slow to meet the rpm for the next gear, while keeping the turbine spinning enough to maintain boost so you don't have to wait for the turbo to spin up again. This also works for launch control when properly mapped - you can sit in the line with the throttle fully down, the ignition strategy of the ecu keeping the engine at the desired rpm and boost level untill you drop the clutch at which point normal ecu functions kick in, albeit with you leaving your diff all over the start line as launching with full boost is hard on the car :shock: In these two strategies the throttle plate is acting as the ALS valve. Do not use proper full on rally car antilag with anything other than a proper turbo designed to take it, otherwise you will be fishing bits of it out of your exhasut, intercooler and pretty much everywhere. Normal Garrett T series are ok for occasional mild ALS, and the full throttle shift / launch control but it will reduce their lifespan. The GT series have a ballbearing core which means they have a much thinner shaft and a non re-buildable core. I wouldn't use any ALS stuff with them. I don't know anything about other manufacturers turbo's. On the subject of dump valves as its kind of related, they are normally only put in buy OEM manufacturers to keep noise down. Turbo's do not normally need them and are actually less laggy without them. This is because although the turbine will slow down quickly when the throttle is shut, the boost is maintained in the pipework so it takes less time to build tubine speed back up than re-charge the pipework with boost. Its especially noticable on quick gearchanges. The exception to this is T4's running very high boost as the shaft can snap due to the shock loading. Right, part 2. Bigger turbo's produce more power for the same boost pressure Forget about boost pressure - what matters to an engine is mass flow of air. A small turbo will have a small hotside leading to a resistance to the engine to pump air. This will give a good spool up but restrict the engines abilty to flow air and make power. A larger hotside will reduce this pumping inefficiency and allow the engine to make more power. The same goes for the compressor side - a larger compressor won't have to work so hard to produce the same boost pressure (in fact it should flow more air for the same pressure) leading to cooler intake temps and in turn creating less restiction to the hotside. The extra power will be at the expense of lag.