Thumper

The tune I put on jeremy's car was very very rich. On my car at 6-8psi my a/f ratio was at 12:1 and then I richened it up 10% for jeremy's car just to be on the safe side. The reason we think it went lean is because he was having problems with his injectors getting enough power. He accidently put a too small of a fuse inline. It finally blew and thats when he reliazed the injectors weren't get enough power. On the timing issue I double checked the timing was spot on with my advancing timing light so we are sure it wasn't that. It still could have been detonation but unfortantely we won't ever know what caused it. Good luck tom I should be over tom night.

Sorry to hear the headgasket blew. But the timing is not set at 50 degrees. That is what the trigger angle is set at. Your timing is 24 at idle then 39 degrees at full throttle. At 7psi I am unsure what timing is at but my guess is 33 degrees. When you go from a oem gasket to either a felpro or hks gasket you compression ratio is bumped up roughly .1-.2 So if you go from a felpro to a hks there is no difference. But if you go from a felpro to an oem then the compression ratio will go down .1-.2 If you are really at 8.7:1 you might want to do this or even go to a 2mm hks gasket. 8.3 would be alot better than 8.7 in my opinion but first see what compression ratio you have. My felpro gasket knock on wood has handled 20psi with no problem with stock head bolts so we better check everything else twice. Also your high rpm miss could be that we didn't have the trigger angle set big enough so your higher rpm timing didn't have enough time to get the signal and send it to the coil. Its a simple fix that we can do if thats the problem. How long after the fuse problem did this happen? If you were going lean then this might have caused your premature failure.

http://forums.hybridz.org/showthread.php?t=102244 Look at the second diagram if you still have problems im me.

Your right that the temps will be lower so there will be less volume. But since he has a higher compression ratio it will compress the air more increasing its velocity when the valves open. So I think the higher velocity will overcome the neglible decrease in egt's especially at lower rpms. This line of debate would not be off topic if I had asked what can I do for less turbo lag or what causes turbo lag, but I asked how can I TUNE for less turbo lag. And in my first post I clearly described my question as tune as in timing and fuel settings. Thanks for your input though I have learned alittle more about turbos but I felt the topic was becoming more of a debate than an answer to my question.

I'm not too sure but I know an easy way to find out. 73turbo240z just got his car driving and he is running my tune on his megasquirt. Only difference between us is that he has an aftermarket intercooler and custom pistons. They have thermal coatings and other stuff done to them. After we get his rings to seat in we will turn the boost up to 12psi and see when it spools. It should be lower since he is running slightly higher compression ratio then me so not exactly comparing apples to apples but close.

Most of this is interesting but has nothing to do with the topic. I've enjoyed reading about 6-7 posts that have actually come close to answering my quesiton but all the other posts were about non-topic related stuff. I would appreciate it if you want to discuss "WHAT makes a turbo spool" then start a new topic. This thread is how to TUNE for less turbo lag and lower the turbo threshold. Baastard- I had the same problem with my t3 when I ran it on my ghetto beast. It started when I put in the 370cc injectors and modified the afm. After doing lots of research and posting a question on hybridz I think it was timing. Since the afm was opening less the timing was different then if it was with a stock afm. I had an adjustable fpr and I raised it 10psi and lowered it 10psi with no effect on boost threshold or lag. I never played with timing since I was at the max I could with the amount of boost I wanted to run. I have now played alittle with my tuning and it seems that advancing the timing 2 degrees during non-boost and low-boost low-rpms areas have helped my spool time. I am running 39 degrees total timing now. I tried retarding the timing 5 degrees and there was a decrease in turbo response. A/f ratio I have not seen a big difference but I have kept it within 13:1-14:1 will spooling. I might try too give it more fuel or less fuel but as for now i'm happy. Any more input on the topic is greatly appreciated.

The turbo head is a p90 or p90a head. The p79 came off of the 280zx n/a engine. For a turbo application the p90 is the best because of the exhaust ports matching up with the stock exhaust manifold. For an n/a application the n42 head is better because it will raise the compression ratio and it has a better exhaust ports over the earlier e88 head. Here is more info good luck. http://geocities.com/zgarage2001/

On my old engine I ran my t3 at 20.5psi and 23psi. Yes I was trying to blow it up. I made 275hp and 369lb-tq at 20.5psi and 280hp and 404lb-tq at 23psi. The difference was only 5hp but the torque went up 35lb-tq. Sure it was only for 1500 hundred rpms but it did make a difference. Your right though not worth it past 15psi for hp but if you want more torque then you might want to up the boost. Oh after running a month at that boost with a starion intercooler I still hadn't blown the turbo or junkyard engine. Although when I pulled the head the pistons had lots of detonation damage on 5 & 6cyl. My dyno graphs are in my gallery. Nice numbers though. I would like to see your timing graphs cause I'm trying to figure out mine right now. Fuel its easier just hook up wideband and move numbers intill you get what you want. But timing for me is more like educated quessing. Thanks

On the driving comparision its kindof difficult because with the stock t3 I was running the stock ecu with 370cc injectors. My lag in first gear was 3900, 2nd, 3300, 3rd 2700, 4th 2500. I believe it had to do with me having to turn the afm to get it to run right with the bigger injectors. But the difference is the turbo spools up slower and hits softer than the t3. But it holds the boost perfectly intill redline the power never drops off. In a couple of weeks when I can get all the little quirks out I will dyno this and see how big a difference it is. Throttle response is better but once again I can adjust my timing settings to help this. I am not sure what the ar size of the turbo is. I do know the compressor housing is 9cm. On the hx35w model the compressor housing is 12cm and is very similar, but inorder to run the bigger one you need to have a spacer between the turbo and exhaust manifold. I have done a few runs with this monster at 18psi and i just flys. I have only done 3rd and 4th gear pulls though. 1st and 2nd just spins my 225/60 bfgoodrich g-force sports. From my point of view switching from the stock ecu and t3, and going to the megasquirt and holset was a win win no loss in driviability, but great loads of power. With 370cc injectors they will be maxed out around 11-12psi so you will need to upgrade to 440's at least to get into the efficiency of this turbo. And I wouldn't even waste my time putting this on if you had stock injectors. Unless you had 12 of them:twisted:

Ok I took out some fuel while building boost and now the car gets 13psi by 2900rpms. I really like this turbo. I would recommend it to anyone who is on a budget. Good luck

I haven't figured out the datalogging yet on it. But will try today. I have an msd6al and a blaster 2 coil, and magnecore wires. The spark plugs were gapped at .030" and I just moved them up to .043" but have only done one run with it as this setting so I am not sure if it helped or hurt. I did over 50+ runs with the gap at .030" and it happened right around 4600 everytime. And then at 5100rpms it would be ok again and run to redline. I am running bpr7es at .030" The missing will first start to manifest it self at 12-13psi and become more and more of a problem all the way up to 18psi. Below 12psi no problems. The other sympton besides the stumble I'm worried about is the pinging. My car should not ping at all at 13psi with 60degree weather and the timing I am running. Also why would advancing the timing get ride of the stumble if it was blowing the spark out. I'm just trying to see all angles. With my t3 setup I could run the spark plugs at .050" at 18psi with the t3 with no problems. I am going to try new spark plugs anyway just incase. Keep em coming. Thanks

I went to tune the car tonight and found that I have an rpm stumble between 4600-5100rpms. It is more pronouced in the 3rd, 4th, and 5th gears. Before and after the rpms it runs perfectly. At the same time as the stumble I also get pinging. Now for the fun part I am tunning with a wideband o2 and it stays at 12.2:1-11.8:1 during full throttle. I have tried less fuel and more fuel. The stumble will go away if I advance the timing in that area by +4 degrees but then it majorly pings. If I retard the timing the pinging is alot better although still there but the stumble is much worse. My IAT's are 75-85 on a 64 degree night. Cylinder temps are 180-210. Also at lower boost I can run more timing so it is not there but the more boost I run the worst it gets because of how much timing I retard. I have also played around with my spark plug gap and it has had little to no effect. Any suggestions? Thanks

The exit on the turbo is 2.5" inside diameter and 2.75" outside diameter. So I used 2.5".

You are right I am quite happy with 12psi at 3100rpms but if I could tune it so it was at 2700 that would be even greater. Also because of my bad piston skirts and soft hydraulic lifters I don't want to go above 6000rpms so every little bit will help. If I can't then I can't but if I can I can. Thanks for the advice but I am not interested in NOS and I know that tuning will help turbo lag that is the reason for my question. Thanks

Well I'm starting to tune my motor and my main concern is turbo lag. My turbo is more than capable of outflowing my injectors so my limiting factory will be them then the stock bottom end. My signature has my specs and i'm running msns-extra 25v2. I have read that in some cases lower timing during boost build up helps since this increases egt's. I have read increasing timing helps because it gives the car more power = more energy = more exhaust gases to spool the turbo. Another theory I've read is during boost build up run engine slightly leaner which in turn increases egt's as well. I have my initial timing at 24, then during vacuum it slowly ramps up to 39 by 3000rpms. Then I retard timing roughly 1.2 degrees per psi. So what do you suggest trying more timing, less timing, more fuel, less fuel, etc...? Thanks

Well a few people have been asking me about how to put this turbo on a z engine, and as far as I know I am first. I got the idea from 73turbo240z and beat him by about a week. The turbo is off of a dodge cummings diesel and runs 18psi stock. They have been known to be pushed up to 28psi on a 5.9l v8. Alot of volvo's and 4cyl mustang owners run these on there engines. With a very rough tune on my megasquirt I get 12psi of boost in 3rd gear at 3100-3150rpms. I can run the stock 7psi, but at 5500rpms+ I have alittle bit of boost creep but it is mostly due to me running the stock 280zx t3 wastegate at a bad angle to the flapper so it does not open all the way. The modifications that are needed to make this turbo work in a z are a different wastegate mounted on turbo since the stock one opens up at 18psi, retap thread holes in turbo for stock oil line or get custom oil lines, new downpipe, new hot side intercooler pipe, and you need to drill the threads out two out of the four mounting holes. The other two bolt holes are already a perfect match for the stock manifold. I have also bored out the wastegate hole to help control the boost level. My butt dyno says at 12psi I have roughly 260-280hp. The car feels just as fast as it use to be at 18psi with the stock t3. I believe I can tune the engine better and get better boost response. I will post up when I have an update. I was able to buy this turbo with shipping for $250.00 So it is a good turbo for a good price.

What are you trying to do? Just set the stock timing on your ecu? Or are you installing an aftermarket ecu? Also what kind of timing light do you have just a static one or do you have one that can be adjusted or advanced? Are you installing the distributor for the first time or just redoing the timing.

One of the easier things to change would be tire pressure. In solo II tire pressure can make a big difference. In my z I would run my front tires at 38psi and my rear at 37psi. Upto roughly 40psi the higher you go the better grip you have. So if your car likes to push then higher pressure in front and lower pressure in rear. Also you can tighten or loosen your sway bar endlinks. To get rid of push loosen the front or tighten the rear. Also you might want to look into getting a strut bar. A good tri-angular bar will help wonders. Good luck.

I did what moby suggested in his write up but still ended up so high. As long as there is no ill side effects then I won't worry. But if you can think of any I will be happy to redo it again. Only takes a minute or two. Also just an update the car does not like 38 degrees at 5k rpms. I had to turn it down to 30degree so that it wouldn't miss. This sounds like I didn't have enough time to set it but if i'm 112 total trigger then I should have had plenty of time? Any suggestions are welcome. Thanks

I have verified that my spark timing is dead on. When I put it too fixed 20 degrees then its at 20 degress the only problem is I have to run the trigger angle at 67 with a trigger addition of 45. So a total of 112! I also have the distributor fully retarded. Why do I have to have it so high? Does it effect anything being this high? I have verified that at tdc my rotor is lined up perfectly at #1 cylinder, I can put a string through the cap and rotor. So its not off a gear cog. Any suggestions? Thanks for your time

Yes I was the first to get it running so therefore MY COMBO:twisted: Actually it was 73turbo240z's idea that made me go with the hy35 in first place. BUT I was first running although in the next week he should be also. Look for an update within a few days.

Well it started early this morning. I forgot to check if the engine was on the compression stroke when I put the oil pump back in so that was my problem. Fixed it and now everything seems to be ok. I can't drive it because I haven't made my intercooler pipe yet and no air filter. The only problem I have is I have to have my trigger angle at 23 degrees in order for my timing to be at 5 degrees during cranking. Also I have no trigger angle addition. I think the oil pump shaft might be off a tooth? I am not sure if there could be anything wrong in megasquirt that could cause this? Other than that the it starts right away and idles fine. Thanks for great right up Moby, and for Olie for letting me borrow his box into mine is repaired.

I tried to start it last night with a low battery and kept on getting back fires. I had to replace my oil pump and I forgot to check if I installed it on the compression stroke. So I am going to check that install the turbo and finish a few more things before I start it. Thanks for looking.

Here is zipped version of the megatune I run. Should be able to just uninstall and open my file. http://www.msefi.com/download.php?id=2607

I found someone to upload my settings for me. Here they are. I am running extra 25v2 and megatune b656. Thanks http://home.earthlink.net/~thtazman/data/extra25v2.msq