Wez Posted August 23, 2010 Share Posted August 23, 2010 There is a thread here on Ryans BW 91/79 as he uses one on his track car http://www.mkivsupra.net/vbb/showthread.php?p=2573292 Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 23, 2010 Share Posted August 23, 2010 Very similar curve to what Ryan got. Very sudden, violent power rise, very sudden torque fall off. I like curves like this: Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted August 24, 2010 Share Posted August 24, 2010 Good to hear Jules! Sorry i couldn't get to all your calls but sometimes when you rang at 3am i just didn't hear it after working in a dyno all day!!! Dave is a great guy and why i put Chris onto him in the first place. Wierd i have been working in his country though! but can see why its all boring V8's over here! Im back thursday after my massive 28 hour flight! Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted August 24, 2010 Share Posted August 24, 2010 Thanks for the kind words Julian. You know me and electrics. Sorting the cam clearances and the VVTi is no biggie to me, but an ecu with no instruction manual and an interface that looks like pre GUI Linux is not something I go into confidently In my spare time over here while sun bathing Chris i have wrote a manual just for you But dont worry mate i have seen some of the best mappers around need help with all the stuff on it! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 24, 2010 Share Posted August 24, 2010 Has anyone got a flow chart for this turbo? Just driven it, laggy as hell and it sure doesn't feel like a near 600 BHP engine, either Thanks. Quote Link to comment Share on other sites More sharing options...
David Reid Posted August 24, 2010 Share Posted August 24, 2010 It was on an open wastegate, he's had it plumbed back into the downpipe now, but I don't believe Julian saw any difference. Anyone know what exhaust housings are available for it? It didn't sound like it was leaking when it was on an open pipe. Can't remember what make the WG is, Julian may see this later. Its available in 0.88 undivided and 0.91 divided, I am guessing he has the devided one as its one of Pauls manifolds. AET can rebuild these and hold the parts in stock. Quote Link to comment Share on other sites More sharing options...
David Reid Posted August 24, 2010 Share Posted August 24, 2010 Flow maps quoted from Full race http://www.full-race.com/catalog_images/Borg%20Warner%20Turbochargers/S300SX%2091-79%2066mm%20compmap.jpg http://www.full-race.com/catalog_images/Borg%20Warner%20Turbochargers/KGsec-LBmin.jpg Quote Link to comment Share on other sites More sharing options...
David Reid Posted August 24, 2010 Share Posted August 24, 2010 Are you sure the wastegate isn't leaking? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 24, 2010 Share Posted August 24, 2010 I don't know, it may be, but if it was leaking when the wastegate vented to atmo it would / should have been audible. Julian has now had it piped back into a very well silenced and civilised exhaust system, but it is apparently easy to vent the gate to atmo again. He's going to try that, as well as look at the diaphragm. It has a seven pound spring in it, apparently, I am wondering if the boost control solenoid is being overwhelmed by flow volume and it needs a pill in the hose? I only had a quick drive in it. Thanks for the chart David! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 24, 2010 Share Posted August 24, 2010 Its available in 0.88 undivided and 0.91 divided, I am guessing he has the devided one as its one of Pauls manifolds. AET can rebuild these and hold the parts in stock. If the turbo and wastegate checks out OK and the solenoid isn't being overwhelmed I would suggest he tries the smaller housing. Not ideal on a divided flange, but a fairly cheap experiment I would think? Quote Link to comment Share on other sites More sharing options...
J_Boulton Posted August 24, 2010 Author Share Posted August 24, 2010 It should spool much quicker on that turbo Chris, its 67mm iirc, i cant see it being cam related either, 272's would not make that much difference to lag time imo. My money is on the turbo is knackered, was it ever inspected Jules? It hasn't been checked yet Jamie, I'm planning on having a look tomorrow. I've got a horrible feeling you may be onto something because as Chris says, it just doesn't feel anything like 650+ but more like my previous setup with the GT4088R which had about 500 at the flywheel... I'm going to have a look at the wastegate as well like Chris suggested to me earlier today. To be honest, if the turbo is knackered I'll be relieved, in a strange way, because at least that explains something. But I'd also be looking for some answers as to why it has after only a few months, particularly as it hasn't really been used much in that time. Could it be that these turbos are simply not spooling early or is it generally the opinion that they should, and do on other peoples setups, but mine is the odd one out and clearly indicates something is wrong? God, what I'd do to get a nice early spooling setup that I can just enjoy. I'll report back with findings when I've checked the turbo and wastegate. And thanks to everyone for their input and help so far on trying to get to the bottom of this issue. Quote Link to comment Share on other sites More sharing options...
J_Boulton Posted August 27, 2010 Author Share Posted August 27, 2010 (edited) Right, the turbine blades are fine, I took everything apart on Wednesday morning and found no indication of damage. Wastegate is fine too. So, I got in touch with AET about trying the smaller .88 housing. They'd got one and could adapt it to the 3" v-band fitting. Then, yesterday morning Ryan called me to catch up on the latest with the car and I told him the turbo was fine. Ryan then seemed pretty damn sure it was the cams causing the problem, and suggested we get standard cams back in to see if the spool improves. Since then the .88 housing arrived and I fitted it yesterday afternoon out of desperation. The result? Bugger all difference. Certainly none that I can notice anyway, spool is just as bad. So It certainly looks like Ryan is right, the cams are the bad guys in all this. So now I have to organise a cam swap and then get everything re-shimmed - yet again. Anybody got a VVTi inlet cam available? (my original one had it's head chopped off when the new ones were fitted) Edited August 27, 2010 by J_Boulton (see edit history) Quote Link to comment Share on other sites More sharing options...
Wez Posted August 27, 2010 Share Posted August 27, 2010 So you have Titan 272 9.9mm lift cams at the moment, how does the VVTi work with them, I guess its disabled at the moment. The stock VVTi setup being controlled by the Syvecs would prob work much better for this setup, improving low to midrange power. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 27, 2010 Share Posted August 27, 2010 The ecu is controlling the VVTi. I think Julian is trying to find a stock VVTi inlet cam, I have a stock exhaust cam, or he may try the HKS Valcon, or whatever they call it, inlet cam, which he tells me is 264 degrees duration, with an HKS 264 degree exhaust cam. I have now been told it has a 1.2mm head gasket, so the already low standard 8.5 to 1 compression is even lower, which won't help his soggy response. Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted August 27, 2010 Share Posted August 27, 2010 Just change the exhaust cam Jules first Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted August 27, 2010 Share Posted August 27, 2010 Hi Julian, Have you got your dyno sheet from SRR to compare to the tests I've done http://www.mkivsupra.net/vbb/showthread.php?t=181671&page=15 I still think its the cams as its the only unknown part of your setup, everything else is proven. Quote Link to comment Share on other sites More sharing options...
J_Boulton Posted October 15, 2010 Author Share Posted October 15, 2010 Right, changed the exhaust cam yesterday and, cutting a long story short, there's virtually no difference. It does now begin to pull at about 4.5k, but nothing of any real consequence and then still only really goes at about 5k. It still has nothing low down and remains like an asthmatic old man. I took a trip down to see LeeP yesterday to get the swap done with the plan of then seeing Ryan is morning to get some tweaks and niggles ironed out on the map, but he couldn't make it so will have to get that sorted next week. Thanks for everything yesterday Lee, it was great to finally meet you. Lee checked the timing of the Titan cams first and everything seemed fine so then went onto swapping out the exhaust cam. During the swap his eagle-eye spotted an issue with the cam caps. On the exhaust side, one was on the wrong way round and on the intake side there were two in the wrong place Apart fom the disappointment of the cam change not working we did get a couple of other issues sorted, the main one being a slack throttle cable which Lee did a nifty job on. The throttle pedal is now much better. Something that Lee did mention was compression ratio and how it might be affecting things. Paul, could you remind me what compression ratio it's running and what gasket you put on? I have got a couple of little jobs to do which may or may not have some influence on things. One is to replace the wastegate spring with a stiffer one. There's a 7psi in there now and I'll replace it with a 14psi one. There's also a slight blow from the turbo gasket so I'll replace that today as well. So, the end result is still no real progress towards getting this issue sorted. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted October 15, 2010 Share Posted October 15, 2010 Right, changed the exhaust cam yesterday and, cutting a long story short, there's virtually no difference. It does now begin to pull at about 4.5k, but nothing of any real consequence and then still only really goes at about 5k. It still has nothing low down and remains like an asthmatic old man. I took a trip down to see LeeP yesterday to get the swap done with the plan of then seeing Ryan is morning to get some tweaks and niggles ironed out on the map, but he couldn't make it so will have to get that sorted next week. Thanks for everything yesterday Lee, it was great to finally meet you. Lee checked the timing of the Titan cams first and everything seemed fine so then went onto swapping out the exhaust cam. During the swap his eagle-eye spotted an issue with the cam caps. On the exhaust side, one was on the wrong way round and on the intake side there were two in the wrong place Apart fom the disappointment of the cam change not working we did get a couple of other issues sorted, the main one being a slack throttle cable which Lee did a nifty job on. The throttle pedal is now much better. Something that Lee did mention was compression ratio and how it might be affecting things. Paul, could you remind me what compression ratio it's running and what gasket you put on? I have got a couple of little jobs to do which may or may not have some influence on things. One is to replace the wastegate spring with a stiffer one. There's a 7psi in there now and I'll replace it with a 14psi one. There's also a slight blow from the turbo gasket so I'll replace that today as well. So, the end result is still no real progress towards getting this issue sorted. I cant see this being a compression ratio problem, unless you have some low compression pistons in there that you dont know about. Do you know what pistons were fitted when you had the engine built? Gasket we fitted was an HKS 1.2mm. Wastegate spring wont make any difference to your problem. I run a 7psi spring on mine. Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 15, 2010 Share Posted October 15, 2010 Could the turbo bearings be shot? If they had high friction that'd really hit the spool time. Are these turbo's DBB? If so a simple test would be idling the car, switching off, and timing how long it takes for the turbo to spin down. Compare that to a similar turbo that's known to be good. Quote Link to comment Share on other sites More sharing options...
J_Boulton Posted October 15, 2010 Author Share Posted October 15, 2010 The pistons are the same ones that were in when I was running the GT4088R, and there was plenty of low down grunt with that setup. Could something with the new head/springs/valves be causing a lower compression? Lee mentioned his car use to have the same trait as mine, nothing low down and then a sudden surge of power. He found out it was due to low compression and once he sorted that it was fine. Quote Link to comment Share on other sites More sharing options...
bondango Posted October 15, 2010 Share Posted October 15, 2010 272 9.9mm lift cams - have they been timed up? Quote Link to comment Share on other sites More sharing options...
Steve Posted October 15, 2010 Share Posted October 15, 2010 Could the turbo bearings be shot? If they had high friction that'd really hit the spool time. Are these turbo's DBB? If so a simple test would be idling the car, switching off, and timing how long it takes for the turbo to spin down. Compare that to a similar turbo that's known to be good. Ian, they are not DBB. Quote Link to comment Share on other sites More sharing options...
JamieP Posted October 15, 2010 Share Posted October 15, 2010 My money is still on a turbo problem, must be driving you insane trying to get to the bottom of this. Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 15, 2010 Share Posted October 15, 2010 (edited) Well the only easy test I can think of is swapping the turbo for another similar one Lag is either a boost leak, exhaust gas not being produced, exhaust gas leaking before it gets to the turbo, or the turbo is hard work to turn for some reason. You've eliminated the first three, so... Edited October 15, 2010 by Ian C (see edit history) Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted October 15, 2010 Share Posted October 15, 2010 The pistons are the same ones that were in when I was running the GT4088R, and there was plenty of low down grunt with that setup. Could something with the new head/springs/valves be causing a lower compression? Lee mentioned his car use to have the same trait as mine, nothing low down and then a sudden surge of power. He found out it was due to low compression and once he sorted that it was fine. I thought you said it was laggy before? Unless that was someone else. We only changed the springs didn't we? If so then no. Quote Link to comment Share on other sites More sharing options...
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