How about staggered Cams? Manual exhaust, Race #400 intake? Would that have the desired effect? Just putting it out there.
hey Ron if you dont want to pull your engine out here is a plan ... run dual intakes ..run it on a dyno swap to manual cams (I have a set series 2 ).. run it on the dyno .. if still not happy .. change to ported manis and deck your heads and run E85
Lots of options And ideas, couple more by pm, keep them comming, giving me plenty of info to chase up
Antilag was used in turbo era F1 and the Group B rally days as an attempt to reduce the effects of horsepower limiting rules. It can be done right, or erm, not so right... limiting factor is how much heat the turbine wheel can handle before it melts So what is it? Antilag combines engine 'hardware' and ECU 'software' to harness fuel 'afterburn' between the exhaust valves, and turbine wheel (in the dump pipe) under conditions when turbo spool needs to be maintained. Basically fuelling is increased by around 15%, with limitations such as throttle position (less than 1/4 or <1.06 volt), and high revs. The ECU then retards timing to ~15 deg BTDC, and sequentially cuts spark to each cylinder (could probably pick up a signal off the CAS for this?) Then the smart thing happens: the EGR valve is used 'in reverse' to not put exhaust in the intake, but put AIR into the exhaust . The retarded timing, high fuelling and opening exhaust valves allow afterburn to travel down the dump and contiunue thru the turbine to maintain spool. This is similar in operation to a jet turbine engine. Whether you chose to go a off the shelf system, or rig something up yourself, you would be able to maintain boost through your corners, and achieve increased torque in what was outside of the powerband previously. Also, this reduces the time to get back on boost under periods of decelleration. It could be done, but not sure how hard the bugs would be to iron out... Here are some thoughts: -secondary injectors for 'antilag' condition, pulling a signal from the TPS voltage -Spark cut- perhaps rig it off the CAS, switching with a relay to trigger the cut by removing coilpack earths? -Retarded timing... probably the hardest part... but triggering safety boost would definatley pull a heap of timing out of the car. - Rig a air solenoid up to the Clutch vac assist. switch ON under antilag condition.Put other end on the EGR valve,which gets its feed from the intake manifold (under boost, with a one way valve) I could not guarantee that this would not kill turbos, melt exhaust valves, or create bigger problems with tuning.
Id love to see some facts there, My car makes 300rwkw with stock auto cams, at 17psi on high flow stock turbos which are way less efficient that GT28RS. How much more can you ask from cams?
you mean 295rwkw at 18psi stock cams can make a lot of power but at the expense of running heaps of boost.
yes i do, the only one ive got on here is this one , it shows 295kw . boost is not shown on this graph, i have the boost one on my garage wall, ill grab a phone pic of it tomoro. My engine has got probably 30hrs of porting and breathing mods, but the proof is there with dyno graphs and the lucky forum members that have had a spin. The dyno charts i have were in summer too on a basic tune, im looking forward to some new results next week, new tune in cold weather will still be less than 20psi though
to be honest i actually wasnt seeing that much more power gains vs psi increase, i think it had reached the volume efficiency of the turbo's if you know what i mean. Plus i still have stock pistons god dammit !!![TIS]
yeah depending on your wheel sizes some hit a brick wall at 20psi. stock pistons? what.. you dont have faith in your tuning no prob at that hp level. A one off run at 22psi ..
Personally think what you have there is really good ie; with 28rs turbos you have full boost @ 4400rpm , @ 40000rpm you have more power than most if not all std. TT's For mine your only real chance of an improvement if any would be 2.5" intake system including Throttle Bodies ... if not already done. Going to smaller cams and or exhaust will do nothing but ramp up the amount of boost you will need to run and decrease power, then you have other issues to deal with, one of them being reliability. My 2 cents ... NZD so not worth much
I'm sorry. It was a generalisation. From the figures I've seen, at around 350rwkw & stock cams there isn't much of an increase in power when boost is increased, just heat. Obviously this isn't the case with every build (mod dependent), but it is generally what I've seen/read/heard.
What about Karl/ 90TTZ's 405RWKW with manual cams & stock ported mani's & 28RS's? I wonder if his graph is similar to yours Ron, I think he had a dyno chart on his build thread. You should ask him
Yep. Also, stock S1 cam gears, only mild head porting and tuned stock ecu. ...although, it might pay to mention that he has no intercooler plumbing, which will no doubt help reduce lag.
yeah, but thats the whole point, ive done alot of breathing mods on my motor and it pays off, thats why i wont be doing cams any time soon
