thehelix112

and here. Dave

AK-Z, Try this little program I wrote: http://www.ozdat.com/ozdatonline/enginedesign/ Lets you play with different configurations and what not. You could use the stroker crank with L28 rods and Z20S +1mm oversize pistons. As there are no shorter rods than the L28 ones you have to reduce pin height on the pistons to fit it in the block. Gives you 2893cc, 9.68:1 static compression. Dave

Call me crazy, but if you have boost, and you are going to be running methanol, why the hell are you interested in reducing the ability of your engine to absorb stresses by reducing the amount of metal in there? Gaining 200 odd cc of displacement is equivalent to adding exactly `sod all' boost. Assuming you aren't going to bore it much but instead are going to stroke it. This increases the rod-angle meaning greater wear, more losses, less hp for the same rpm, and less rpm available. What is good about it? If you are going to make 500rwhp you will want a big turbo which will come on late. Low rpm means small powerband (not an issue with an auto I suppose) LD28 stroker engines (without the LD28 block) are a complete waste of time if you have boost IMHO. What you could do is get pistons with a smaller pin height and longer rods (reduces rod angle and a few other things I can't remember). I completely agree with Simon (zbuild), don't bugger around with crap EMS, Motec are the best, and you get what you pay for. Even autronic (which I run at the moment) are a very poor second compatatively. Dave

Dennis, I'm using the RX7 460cc injectors at the moment too. Haven't seen them go much past 50%DC (and my engine is still running a tad rich), so I dare say they'll make the power you want happily enough. I also dare say you will want more than 350 soon enough. I don't know Steve personally, but have emailed back and forwards with him a few times. What are you chasing from him? Richard, You realise you could be making almost half as much power again if you hadn't accidentally misplaced two cylinders? Dave

I'm making around 270rwhp (australian spec hp I might add) on 10psi with an internally standard L28ET. There are many different ways to get the hp you want, and what on earth makes you think that anything over 14psi isn't reliable? Bobbycock. I plan on running around 20psi through the standard L28 (F54/P90) so we'll see how long that hangs together. I'd be interested to see the dyno graph for your engine once its done, I bet it'll be making some nice power down low, especially with a baby T3/T4 turbo. Dave

True. But you can work it out for a turbo engine based on boost pressure and average intake temps. Needless to say it will be much smaller for a FI application than a NA one. Dave

Garrett, let us know how you go at the dyno when you get a chance. Dave

http://www.jongbloedracing.com/jong_gt.html according to that the 214s are available in 15,16,17"? Dave

Could definitely be a turbo-timer, I'm not sure how sophisticated the SDS is but I'd try turning off all the `cuts' in it for the time being, either that or check its error history to see if it will tell you if its cutting anything on purpose. I just read the other thread on your problem, did you follow the advice there about checking decel fuel delivery? Basically it should go to zero. And about heat? Insulated the coils and as much of the other electrics as possible? Dave

Garrett, Nice results there mate. I'm going to have to get mine onto a dyno as soon as I've put a decent transmission under it. WRT your problem, I'm unsure about SDS systems, so lets see if we can't figure out some more stuff: 1. When you say backfire do you mean unburnt fuel in the exhaust? Or do you mean a backfire backfire as in through the intake? 2. If you are sitting there and you rev it up and down a few times (to simulate driving) does it die if you back off? 3. Where is the O2 sensor positioned for tuning? (please assure me thats its a wideband O2 sensor) 4. Have you hooked up a simple knock sensor to see if its pinging? 5. What AFRs are you tuning for under boost? Possible explanations assuming your wiring is correct. A. Your tuning is ridiculously rich under boost but you don't notice because it is burning in the exhaust before the O2 sensor (this is obviously more likely if the O2 sensor is in the exhaust tip). I suggest you put the O2 sensor around 30cm (12") from the turbo in the dump pipe. This gives you an accurate reading but still gives the gases a chance to cool and ensures you don't get O2 errors because of a pressurised exhaust charge. B. Your ignition is not up to the job of sparking the charge on boost. Check your wiring and change all your spark plugs and set the gap to 0.75mm (0.030") just in case. Also look at the plugs and see if any are discoloured? They should all be clean and a very slightly brown colour if things are working correctly. Actually, now that I remember you said its blowing fuses, forget all that and fix your wiring. Oh and I know what you mean about them giddying up on low boost. Even on my stock F54/P90 engine with a GT35R (equivalent to a T61 or thereabouts) 10psi is flying apparently around 270rwhp. Good luck and keep with it, you know its going to be fun. Oh and lemme know when you munch your first gearbox. Dave