So results from the dyno (will post chart later) not as good but still nothing to cry about. 338Kw flat as a pancake from 5000RPM to 6500RPM, actually down on power by ~25Kws Why? two reasons: suspected bad batch of fuel as we had to pull two degrees of timing out of the ign. Two: valve springs are to soft for higher boost settings. Neither of these things are a big problem as I have a brand new set of valve springs on the shelf for the engine & will get a mild grind done on the cams & fit them at the same time. The springs that are in there have done at least 250000kms & have had one hell of a beating at times, they have an extra lower valve spring seat but other than that are stock. Absolutely no surprise at all that they became a weak link about now but interesting that they were happy last time but showed poor health today ~1000Kms later. Boost control issue is 100% resolved as far as I am concerned but the tuner is fussy so wants to run it through the Link, it needs to go back for a re tune with the new cams so will sort it out then. None of this will be done next week as I simply don't have the time so Superlap will be run at 18PSI as all was well and good there with ~340KW = nothing to complain about
So new valve springs & cams, retune with higher boost & 400KW+ before Superlap? should I try? I have five working days :rofl: Maaaaybe I had better just wait until AFTER Superlap ... But I will send some cams up nth for a quick tickle up ASAP Monday morn just in case I get all silly & start the job.
I "think" you might be wise to........................... fit them NOW!!!!!!!!!! LMAO You want to dont you.................? E
Tempted but I have some other things to do, mind you there are 24hrs in a day ... What a dyno chart looks like when the engine is not happy: Not the weird unexplained dip in boost part way through one of the runs (the red one) never did it before or again - I think it got tired of giving us subtle hints about not being happy so just chucked in something more obvious LOL!
So I created some spare time this afternoon and have replaced all the valve springs with brand new Z1 items, there will be better options out there and people will say I should have used xxx yyy brand but they are in there now and should do the trick! Spare cams are at Franklin cams in Auckland and should have had their surgery by now & might even be on the way back down (will check in the morning), I've asked for just a very mild grind as I'm not interested in specing the cams to high for the turbos, clutch, injectors, head work etc etc etc. Possibly will have it running and ready for tune again by mid day tomorrow
BDE gears from Mikes car are sitting on the bench waiting for me to send them back to Brett for his opinion on them, I'm not sure he will find anything as I had one apart and attempted to improve its performance by freeing it up a little (Brett is aware I was attempting this). I'm actually tempted to try them in my car to see if they will work fine in another engine but with the schedule for this week being so tight it wouldn't be a smart move.
New cams arrived at 4.30pm today and had the engine ready to start by 6PM, Still need to fit boost hoses and radiator etc but it should start if I were to try. New cams are 272 degrees duration and 8.8mm lift as compared to stock at 248 with 8.5mm lift. Will finish bolting it all together in the morning then dyno in the arvo, should be an excellent opportunity to demonstrate what can be gained out of cams alone (aside from the spring issue interfering).
Right so I get the car back together and running then headed to Tauranga to see if there was time to sort the tune. The car ran fine on the way over but did need some adjustment due to the new cams. RESULTS: cheating using old (Mike C knows how old I'm not sure) AVGAS mmmm avgas We got 366KW at the wheels on 17PSI boost there was more to be had except we have now found an ignition issue that needs sorting, the spark was not strong enough it seems. NEVER had a problem with this before so something must be on the way out after 20yrs & probably 3-400 dyno runs. Genuine 98 pump gas netted 366kws at the wheels at 23PSI but a much fatter power curve at the top end, anything over 4500RPM was a long way better off than previous runs. Not bad results for VERY mild cams 8) We did some other testing as well while we were there and removed both rear mufflers to test for extra power - nothing! no real gains to be had! Heaps louder but only a couple of insignificant little bumps of extra power, less than 5Kw & only in a couple of spots. I know for a fact my down pipes I made years ago (2006) are now most likely a restriction as they were never made for anything more than ~300KWs This is an EASY fix and should get instant results if I want to go further. That's enough for now though
When we get a decent batch of 98 that is what it is meant to be there isn't a lot of difference between 98 and Avgas but at the moment we've got crap it seems. I'm looking at making/buying a better set of downpipes to test for any gains, it should open it right up but I'm all for proving results with reliable test equipment. Would like to try a set of 2.5" boost pipes but unless they make huge gains they wont stay in the car as I'm trying to keep things looking tidy and uncluttered while not straying to far from stock if possible.
Hey Glenn how are you finding the big duration small lift in regards to spool? I prefer a smaller duration and bigger lift . but I know with regrinds you are limited with base circle.
We found the spool to be almost identical to stock cams, just ever so slightly earlier, once past 4500RPM things were way better. I'm with you in thinking bigger lift and less duration is probably better with having less overlap etc but these seem to have worked well for what they are and it's probable that with more duration and less lift it's easier on the cam gears. I do have the charts here on the table next to me but I've been to lazy to take a pic and host it etc, it's hard to see exactly what's going on in any case as we left to many previous runs on there - looks like a plate of spaghetti :rofl: There was the potential to get the cams built up etc but I really only tweaked them because they had to come out, I wouldn't have pulled them out to do anything to them specifically at this point. It was funny taking the mufflers off and testing for gains, I had two people there thinking we would see good gains, we got stuff all :rofl: It WILL be different without the bigger restriction at the front but still it made me chuckle.
Avgas is just that, Aviation gasoline. Its designed for large displacement, low revving, low specific output engines at high altitude where its difficult to control flame front propogation. Large amounts of TEL and other gooligum in Avgas give it its properties are not conducive to a high performance turbo car engines which are(relatively) small displacement, high rpm/specific output operated at low altitudes. The bang is too slow basically and requires weird amounts of timing advance and so-on to get maximum cylinder pressure at the ideal crank angle!!!!! So, at the end of the day using Avgas in a performance engine actually results in lower power outputs than using a specific automotive race fuel. What it does do is successfully mask fundamental tuning stuffups that would otherwise occurr using automotive fuels and save the bacon of many a race engine tuner!!!! Try some specific turbo engine race fuels, Elf LMS comes to mind suitable for a turbo engine, to get your bigger horsepower numbers!!!!!! The onlky cool thing about Avgas is its nice smell!!!!!!! L8r E
Yeah C16 or similar would have done better but that shite is EXPENSIVE as hell here, the best you can do is over $4 per litre so not really worth the $ just for bragging rights IMO. No doubt the car would make more power but not my thing (looks at tittle of thread ??) I mean tweaking the car just for the sake of a big number on the dyno that can't be reproduced on any other day is not my thing We know that if I choose to I can crank the car up on shity ole 98 and make ~360KWs any time I like. Tomorrow is Superlap and it's going to be raining - this should be fun LOL!!
Holly pile of swear words Batman!! I think I will leave that to the guys with deeper pockets - especially given the one litre per Km fuel consumption I get at the track :rofl: (something like that anyway - maybe 500mls per KM)
So I had to kill a little time today down at the shop so I chucked the car on the hoist and pulled off the passenger side downpipe, this was built in early 2006 and my power goals at that point were fairly sedate - around 300Kws. The pipes did the job at the time well but we think they are now causing a restriction, to test this I gave the passenger side one a slight tweak. As it was: Two inch main pipe from the turbo down to the rest of the system that is 2.5" not a very nice transition from 2" to 2.5". Removed the offending section of pipe as per: Installed a tapered 2" to 2.5" section of pipe and tidied up the dogleg at the bottom: Much nicer than what it was so once I have given the drivers side a similar treatment I will be off to the dyno to test for results, IF there is an improvement then we will try 3" expansion pipes and see how we go.
