ECMlink WISEMEN WANTED: I need help with my timing map and spool up.

[92nolatist]

I know theres a couple of these threads already, but none that have to do with my current situation. I have and "old school" fp red turbo with 8cm housing, and Im having some spooling issues. It wont start to spool until around 4-4.5k and full spool ~25lbs around 5.5k. Not to mention its slow as dog poop leading up to spool. I have GSC S2 cams in it as well. Im just wondering if its just my tune or a combination of things. (Ive read countless times that these turbos can have full spool around ~4.5k.)

The log I uploaded doesnt go all the way to redline due to knock and only gets to 21lbs, but is my most recent log, and it shows you the point of the thread, horrible spool and timing. Ive messed around with timing so many times and its quite aggravating because Ive loaded evo8 stock and modded maps, 2g maps, taken a stock 1g map and revamped it totally, and now im currently on the GSR Ralliart map with a little tweeking in the WOT section; and it still wont help with spool at all.
So Ive come to you lovely people for help and understanding, what am I doing wrong?
Thanks, Dave.

 

[Boostdriven]

Looking at your log I wonder if you have your base timing set correctly, you are getting knock in places where your timing map is lower than stock settings. If you installed cams in to your car and did not check your base timing that could be part of the problem why you’re getting so much knock.

How much vacuum do you see at idle (950rpms)? With those cams your vacuum should be around 11-13, if you see more then 15 and less than 9 then you may need to degree them, there is an easy way to do it. If that’s the case on your car let me know and ill explain how to do it.

Your slow spool up could be due to a boost leak. You may not have a boost leak on the pipes but your BOV could be leaking as well. I put together a timing map for you that you should be able to run if everything mechanically is set correct. It will probably need a little bit of fine tuning to your car but it should be close. Also take a look at the maxoctane table I put together and compare it for what you have. I have a similar map on my car and it works well for me. Just few ideas for you to look in to.

 

[92nolatist]

I was wondering the same thing but i havent gotten around to check it. When I put the cams in(6,000 miles ago), I set the base timing correctly; and the vacuum at 800 rpms is anywhere between 5 and 10 inhg mostly 8-9 tho. So I guess Ill have to degree them right?
Last I knew, I dont have any boost leaks, but there is a tiny leak between the o2 housing and turbo, but thats post turbo and wouldnt affect spool, or would it?
BOV is a forge 1g valve and I did have to put a little silicone on the flange and gasket to get it to seal but its still good. I do have to take it off tho to fix some full boost fluttering that Im getting around 25lbs. Probably just a shim or two should do.
The map looks good, Ill give them a go tomorrow on my day off, hopefully it wont rain.

 

[Boostdriven]

To low of a vacuum could mean to much over lap which could cause a slower spool up. 800 rpm idle is a little low for those cams, I try to keep my right around 950 but if it idles fine at 800 then don't worry about it. I would try to bring up the idle to about 1000 and then see how much vacuum you're seeing in your log, if its still less then 10 then you might want to try and advance exhaust cam few degrees. Remember thou, 1 degree on a cam gear is 2 degrees on the crank so if you advance your exhaust cam 2 degrees on the cam then it will be 4 degrees advanced on the crank, try that and see if your vacuum gets better at idle, it might help with a spool up as well. Also you might want to retard the intake cam like 2 degrees meaning only moving the cam gear 1 degree. Let me know if that helps any.

 

[92nolatist]

It idles perfect at all settings under a 1000 but ill bring it up to a thousand and ill see what's up. I don't have adjustable cam gears so thats a problem....

 

[Boostdriven]

Well at least check you're ignition timing, ground timing with ECMlink and set it to 5 degrees BTDC.

 

[92nolatist]

I was reading up on the use of adjustable gears and I think what you told me to do is backwards. I have a quote here from this thread http://www.dsmtuners.com/forums/newbie-forum/349312-adjustable-cam-gears-how-necessary.html and it says that retarding the exhaust and advancing the intake is better for mid range and lag. You said the exact opposite. Can you explain why?

........Generally, advancing a cam gear opens a valve sooner, and closes it sooner... retarding the cam gear, opens the valve later, and closes it later... since all you've done is "move" the fixed event.

Advancing Intake and Exhaust : This will provide the car with more bottom end power, and will decrease top end. Advancing both cam gears will move overlap earlier but will not increase it.

Retarding Intake and Exhaust : This will increase the cars top end, but will decrease low end. Retarding both cam gears will move the overlap later and but will not change the amount of overlap.

Advance Exhaust Only : This will help the cars top end, and it reduces overlap.

Retard Exhaust only : This will help the cars mid range power, very useful for cars with big turbos / big cams. By increasing overlap, It decreases lag significantly. Doing this will bring the boost on all at once. Very common DSM modification.

Advance Intake only : This will increase overlap and helps the cars bottom end and mid range power. This mod will bring the turbo on all at once, although isnt a very common mod for DSMS.


There is a ton of info on this topic if you need more, both here and all over the net."


Best of luck to ya!


PE

Oh and at 1000rpms, Im right a 9in of vacuum.

 

[Boostdriven]

The reason why I told you that was because you said you have low vacuum which is usually because of to much overlap. When you advance the exhaust cam it mean it will open sooner and close sooner and when it closes sooner it decreases overlap. With the intake cam its the opposite, when you retard the intake cam it opens later and closes later and when you open the intake cam later that also decreases overlap. So when you decrease overlap you will have more vacuum. If you do the opposite of what I told you, you will increase overlap and therefore have even less vacuum.

Another reason why I told you to do a little bit on each cams because with out actually using a dial indicator its hard to tell which cam is off and how much to cause low vacuum.

EDIT
Let me back up a little bit here I wish I would have done this before I started talking to you about cam degreeing. I just looked up the specs on your cams and I have to say that 9 inches of vacuum sounds about right. According to what I found it says that GSC S2 cams have 230* duration @ 1mm valve lift. 230* of duration is allot. Those cams should be a top end monster. I'm not surprised that you have such a slow spool. With these cams you should be running an HX52 and turning that engine at 9500 rpms

According to the specs the intake cam has a centerline of 107* ATDC so if you take 230*/2(centerline) = 115* each way of the centerline. Now if you take 107*-115*=-8*, meaning your intake cam will start to open and have 1mm lift at 8* BTDC. Now if you take 107*+115*=222* and 222*-180*=42* meaning the cam will be at 42* ABDC and have 1mm lift (closing) so 8*+180*+42*= 230* of duration @ 1mm lift.

According to specs the exhaust cam also has 230* of duration @ 1mm lift but it has a centerline of 113* BTDC. So again you take 230*/2(centerline) = 115* each was of the centerline. Now if you take 113*-115*=-2* meaning that your exhaust cam will be at 2* ATDC and have 1mm lift (closing) and if you take 113*+115*=228* then 228*-180*=48* which mean that the exhaust cam will start to open and have 1mm lift at 48* BBDC

So if you look at where the intake opens and exhaust closes in relation to TDC you end up with 10* of overlap @ 1mm valve lift, 8* BTDC + 2* ATDC = 10*
I run kelfords 272s and I have them degreed to have 6* of overlap, that's what the spec card calls for. At about a 1000 rpms I get about 11 inches if vacuum, maybe 12 so with 10* of overlap 9 inches of vacuum sound about right.

If you have a dial indicator you can check your cams to see how close they are to those specs just for piece of mind and to see if you need to spend money on cam gears or not. If you haven't read one of my posts on how to degree cams with out a degree wheel let me know and I'll explain it to you, its actually fairly simple.

Now for degreeing those cams to get more power or spool up out of them I don't think there is much you can do because due to their long duration they are pretty much maxed out on both end. You might be able to advance the exhaust cam 2* and retard intake cam 2* to reduce the overlap to 6* and get batter vacuum and maybe a little more spool up but now your moving the opposite end of the cam even further then it already is. There is a reason why they make those cams have more overlap and its because there isn't much gain from keeping the intake cam open past 45* ABDC and the exhaust cam open before 45* BBDC. I hope this clarifies it for you a little more.

Let me know how the tune comes along with those new maps I sent you.

 

[92nolatist]

Wow, that is a very informative post, thank you! I do want you to explain to me how to degree them without the wheel because I want this setup to be awesome. Unless what you said In your edit is how?

Base ignition timing is dead on 5* BTDC. I did a compression test on thursday to see how my engine is running 27,000 miles after i built it. The compression is 135 across the board :/ With a capful of oil, its 155. I definitely think its because of how the cams are degreed in the stock format with stock gears. Im kicking myself because I never did a compression test with my old FP2 cams to see if it was different. It should be higher because of the 8.5:1 pistons I have in there. Before I built the motor, in its stock form it was at 180 psi with engine fully warmed up. I read how with big cams, the compression can be lower due to overlap. Heres the article: How do cams affect compression? Whats your take on why my compression is so low? Due to the cams not being degreed properly? Let me know, please.

Im still knocking pretty badly with your maps, could it be because of the cams as well????? They do feel good though, and slightly better spool. Ill grab a log when i can.

I appreciate your help so much, you have no clue haha.

 

[Boostdriven]

I have kelfords 272s degreed to have 6* of overlap. Last time I checked the compression, with my 8.5 compression pistons I had 155 psi on a fully warmed up engine with about 20k miles behind the belt. Considering your cams suppose to have even more overlap (10*) I would say 155 psi is about right.

I've read through that article and that's some good information there but the article explains only one aspect of the cams which is the overlap and how that effects the engine throughout the rpm range. There is also the opposite side of the cam that effects the way the engine makes power as well.

When you take an intake cam that still has 1mm lift at 42* ABDC that means the crank is about a 1/4 way up on its compression stroke before the valve is actually closed. At high rpms that is beneficial because as the piston is traveling down on the intake stroke it creates a low pressure point inside the cylinder allowing the higher pressure in the intake manifold to fill the void. As the piston reaches the BDC you may think that it stops taking air in but that's actually not true. At high rpms when the piston is traveling very fast the void in the cylinder requires more time then the stroke itself to fully equalize the pressure between the cylinder and the manifold, that is why they make cams that hold the valve open well past the BDC. During the rotation cycle of the engine the piston reaches its maximum speed (up or down) when the crank is at 90* from TDC or BDC. As it passes that point of 90* it starts to slow down until it fully stops moving at the BDC or TDC then it starts picking up speed till the crank reaches 90* again. Here is the important part that comes in to play, when the piston starts to come up from BDC it moves only a short distance in the first 20*-25* from BDC so keeping the valves well open at that point allows the momentum of the air entering the cylinder to equalize the pressure.

Now at low rpms the long duration has a negative effect. At slow engine speed the valve does not have to stay open as long to equalize the pressure so keeping it open past that point where the pressure is equalized allows the piston to push some of the air out through the open valves back in to the intake manifold reducing the amount of air compressed which reduces power due to lost compression and due to lost compression you have weaker exhaust drive which essentially slows down the spool of a turbo.

Long duration on the exhaust cam has similar effect but in a way backwards. After the ignition on the down stroke the piston has the most leverage on the crank when its at 90* from TDC, and as it goes past 90* it starts to lose leverage. The further the crank moves past 90* the less drive the piston has on the crank and by the time it reaches BDC there is nothing moving that crank further except the momentum in the crank itself. So having said that, for any given rpm there is a sweep spot where you want the exhaust valve to open. At lower rpms you want to keep that exhaust valve closed as long as possible to get a little more drive from the piston on the crank but you also want it to open early enough so that when the piston reaches BDC and majority of the pressure in the cylinder escapes before the piston starts to travel up. So let's say for example at 4000 rpms the engine produces the best torque when the valve starts to open at 30* BBDC and by the time its at BDC most of the pressure is released in to the exhaust and the piston just pushes the rest of it out on its way up. Now at high rpms when the piston is moving faster it requires more open valve time BBDC to released the pressure, that's where you want the exhaust valve to open sooner. The side effect of that is lost torque in the lower rpms.

There are allot of different factors that come in to play when you start talking cam duration and how it effects the overall performance of the engine. Going with big cams on a stock intake manifold could cost you low end power while not gaining much at the top end as the intake manifold will become a restriction. The same goes for the turbo, if the turbo is to small to be able to support the air flow to the engine at high rpms efficiently then big cams are not going to help you there either, you will end up with higher drive pressure and boost dropping off towards the top of the rpm. Hope all that makes sense, its late and I'm tired

Now to answer your question about degreeing cams. First you want to check where the cams sit right now, for all you know they may be exactly where they need to be according to specs. You will need a dial indicator to do this. First start the engine and let it run for a minute or so just to get the lifters full of oil then pull your valve cover off. To check the intake cam turn the engine to where its about to go on the intake stroke on cylinder #1 Set your dial indicator on top of the intake valve retainer of cylinder #1 and set it to 0. Make sure its secure and nothing will touch it as you rotate the engines. When you do that, turn the engine forward by hand slowly and watch the needle on the dial indicator, as soon as you see that valve drop 1mm or .040 thousands then stop. Now look at the timing marks on the timing belt cover. If the cam is where it needs to be then the mark on the crank pulley should be about 8* BTDC. You can kind of guess where 8* is in relation to the 3 marks that are on the timing belt cover (-10....-5....0) if the mark on the pulley is before the 10* mark then you will need to get cam gears and degree the cams. I would say the same would go if the mark was past 5* closer to 0.

For the exhaust cam you want to do this backwards. Turn the engine forward till it fully completed the exhaust stroke and the cam lobe is completely of the rocker arm. Set your dial indicator on the exhaust valve retainer of cylinder #1 and set it to 0. Now rotate the engine backwards but this time you want to go a little bit past the point where the valve is open 1mm or .040 thousands, maybe to where it drops to 2-3 mms and then turn the engine forward till the valve comes back up to 1mm. The reason for doing the two step process is because there is always a little bit of slack in the timing belt. The engine does not spin backwards so when you turn it backwards the slack in the belt will give first before the cam moves and you will not get as accurate of a reading. So when the valve is at 1mm lift look at the timing cover marks again. If the cam is where it needs to be then the mark on the pulley should be right about 2* ATDC. Again you will have to kind of guess on where the 2* mark is judging by the space between the other 3 marks. If the pulley mark is before 0* (TDC) or much further then 2* ATDC then I would suggest getting cam gears so you can adjust the cam to where it needs to be.

About the knocking issue. What is your air/fuel ratio at the point where it starts to knock? When I pulled up your log on my laptop I couldn't see the wideband readings. What kind of plugs are you using and what are they gaped at? How old is your knock sensor and where is it located? There are 2 places it can be screwed in to. One is right at the top of the block deck and the other is towards the bottom of the cylinder. I have my right at the top of the block deck.

One way to tell if what you are seeing is true knock is to pull like 5* of timing out of the cells that are being used where you see knock as well as few cells around that and then do another pull. Basically you can highlight a section of your timing map and drop those cells 5*. If you still see the same amount of knock then it must be coming from vibration or other noises in the engine. If you get a chance post another log and I'll take a look at it again and we will go from there.

 

[92nolatist]

You are the MAN with all this info! Thank you! Funny thing is Im a mechanic and I know alot about cars, but this is going into depths that I never even thought of!

Its a lot to take in at once, but Ill just read it over and over so I get a true understanding of everything. Ill have to draw some pictures of all these different things to get an even better understanding, pictures make books better so why not with engines as well haha.

Alright, so compression is good then, whewwwww, thats a load off my shoulders haha.

I know exactly what youre talking about with the degreeing part, thats not a problem for me, I can easily do that. So then Ill just degree them that way and Ill go from there if anything needs to be adjusted. Sadly enough though, I am extremely tight on money at the moment and if I do do anything, it might not be for awhile

My AFRs are at 12.7 at 5K rpms and 15 psi right when it starts knocking (I took a log yesterday coming home from work), that seems a bit high actually. My SD table is no where near perfect either, so Ill have to adjust that lower. Im using BR7ES plugs at .022. My knock sensor is 27K miles old, bought oem new when I built the motor, and its in the lower hole which is right above the rear balance shaft. Should I move it to the upper one? Ive also heard that people put a nylon washer in between the block and the sensor as well to help combat engines noises that it picks up as "knock".

Heres the log from yesterday:

 

[Boostdriven]

I haven't had the chance to look through your log yet but if you say you have 12.7 air/fuel ratios at 5k rpms with boost as high as 15 psi I would say that's part of the reason why you are seeing knock. 12.7 is a bit to lean, it should be at least 12 or lower at that boost level. Keep in mind, your stock boost setting isn't as high but the air/fuel ratios are much richer at that rpm. Now that you have a good maxoctane table play with the VE table to get the air/fuel ratios a bit richer and see what happens. I found it easier if you set your maxoctane table to where you want your air/fuel ratios to be then all you have to do is watch your wideband reading in relation to air/fuel ratio estimate. In open loop under load your air/fuel ratio estimate will display the values that you have programmed in to your maxoctane table.

I haven't heard anything about using some kind of a washer under the knock sensor and I don't know if its a good idea. If it picks up less noise due to that washer I would think there is a chance that it might miss something important and it could cost you more money. For the knock sensor location honestly I'm not sure where it is from the factory, haven't seen a factory dsm for a while now I have my right at the top of the block deck, its been there for years. I've seen them in the bottom hole as well and they seem to work there too.

 

[Boostdriven]

Any updates on your situation?

 

[YZFR1]

Just thoight i'd mention that with GSC S2's i get anywhere between 12-15 in/hg depending on how i have the cam gears adjusted. My centerline was checked with a dial when the motor was built and it was on point, no adjusting was necessary to have them straight up.

I think having less than 10 inches of mercury is a little low.

 

[92nolatist]

^ I agree too, I just havent gotten around to checking that yet, Ill wait til after the shootout.

I havent touched my car in a week, but before that I was tweaking my SD table to get my air fuel in check, doing a pull and adjusting, doing a pull and adjusting.... Still getting some knock so I lowered my timing map a little in the area where its knocking and surrounding cells. This week Ill be doing more to it to get it ready for the shootout.