Found the root of engine problem

[mavila1]

RUN ALCHOHOL. YOU NEED A HIGH VOLUME FUEL PUMP AND MORE INJECTORS OR REALLY BIG ONES. YOU  CAN RUN A RICH FUEL MIXTURE AND METHANOL WONT HURT ENGINE PARTS. ALCHOHOL HAS A VERY HIGH OCTANE RATING, YOU JUST RUN THE SAME INJECTOR AS YOU WOULD FOR PLAIN GAS.  THIS IS MUCH CHEAPER THAN RACE GAS OF 112 OCTANE AND 93. GALLON RUNS FOR .63 CENTS. NOT TO BAD. THAT IS HOW I PLAN TO RUN. 8)

[Tim_C.]

Chip: Joel is right about lean & rich. they both seem almost the same, so I would trust your AF gauge.

 

Mavila: Alcohol is fine, but if it EVER goes lean, major meltdown happens. You can not ever go lean with alcohol. So, an EGT, AF Meter, all gauges & meters numerical & very accurate, fuel system calculated to run 2 bars rich, with adjustment on the fly capability. (Boost Controller will work) With everything right, alcohol runs much cooler, but just make sure.......

 

Mike K: I really think it is the cam that has a lot to do with the RPM drop off. BTSG is running a Baker I think, and a degree wheel/gear. I must say that mine pulls so hard to 7K RPM, that the roller cam is the answer. My grinder told me that Schneider has big numbers for lift and duration to sell the cam, but they just don't perform to expectations. He guarantees me a better performing cam w/much less. He can even do a slip rocker regrind of the stock cam to out-perform the Schneider.  We are working on a very finely tuned grind for our cars. I told him it will need to out-perform the 284F Schneider. He said he can do it. He can grind a mechanical slip rocker cam too. (His preference) I want roller hydraulic because most guys don't want to have to adjust it, plus, there isn't an affordable option for a mechancal roller rocker? The roller advantage can't be disputed either.

I can't get out of first gear fast enough before the engine is at 7K. Second is the same way. It wants to just pull so fast that its all I can do to keep from over-revving. I've still only gone over 7K once, but Steve @ TEP said they take their motors to 7500 on road race tracks. My bottom end is as good or better than theirs I think. I finally got it right. I'm almost afraid to go MPI. My boost is still 10 PSI. I still have the fuel problem, so I've got a DVM on the O2 to keep a very close eye on it. I have to bump the FP to 70PSI to get enough to run 10 Lbs. boost? Time for an increase. You all know my options. I'm trying to decide which way to go? I'm so close to stoich now, so I may get this working right, and then sell a good working upgrade before going to MPI?

 

Bigger fuel line & pump will help for sure. You can always regulate volume down, but you can only regulate up so far.

 

Tim C.

[chiplee]

I'm trying to look at every aspect of this thing mike and I'm reading stuff that makes me think the 1:1 rise that FPR is giving is not enough  If my stock lines and CNM 125psi pump arent falling short then I'm not positive but I don't think you're flowing enough more air than me to make that combo fall short.  Well first I didn' think the magna FPR was enough so I mounted the CNM BCFPR behind it just like it was mounted on my stock set up.  Much of what I've read tonight says that people are using 2:1, 2.5:1, or even a 3:1 variable rate regulator.  I know the injectors will increase duty cycle to compensate but adding 1psi of fuel pressure per psi of manifold pressure is simply not enough IMO and in the opinion of about 3 articles I've read.  Now if your base pressure was hi enough you may not have noticed it but you should have been idling very rich if that was the case.  Of course just jacking up pressure is not the answer either you know better than I that injectors are designed to work in a certain pressure range.  setting idle pressure should of course be done with the vacuum line to the FPR disconnected because it will reduce fuel pressure 1:1 just like it raises it 1:1 so if you set 50psi at idle with 20in of vac you just set 70 psi at idle cause that's what you should have when the manifold pressure hits 0.  Pressure has effectively risen 20psi from -20 to 0.  Make that mistake and at 18 lbs of boost you're looking at nearly 90lbs of fuel pressure, which is enough to lock up some injectors.

[Joel]

Let us not forget that you will need more fuel volume on alcohol. It brings its own oxygen, so to keep the AFRs up you will need larger injection for the same air volume in the motor.

 

I keep asking myself the cam question too... I have a 284 Mechnical cam (for a mechnical drivetrain) and it will piss me off to see it drop at 4k on that cam.

 

I'm wondering if your machinist/cam grinder will be able to sell the cams at an economical price? Also, if they need a test dummy for the cam, I'll gladly swap cams and dyno on a mechanical setup to see what it'll do, I'll do it. Don't care if I get anything for free, I'll buy a good working powerful cam if the schnieder ends up to be s***. I did notice the cam Bill was running, and had questions about that myself (wondering how much better it is over a schnieder)

 

I would like to hurry up and get my parts all in and built to see what this thing does...

I will say I'll be disappointed if I run into that 4k drop even with only a 16G. I expect to see 240HP or so on pump gas, thats what I want out of this turbo.

 

Joel

[Shelby]

has  any one  realy  degree'd their  cam to see just  where it is opening, how close it may or may not be to the spec's set  for it

as for cam grinds , even a 284 isn't very agressive, most   hi po  v8's run a factory 276,  and  even the 292 isn't  much better in a v8,  i've use'd all of them  292's 300 310, 320 and  even a 336  crane 550 lift  roller with  rev kit,  any thing over a 310 requires a  standard tranny or  one heck of a hi stall  convertor  for street use, we had a 3500 stall on the  crane roller and  2k was as low as it would idle and stay running, at 2200 the slicks would  try to turn on  you  lol

so whats the   idea  of going to say 300 degrees , i  know the idle  quallity would suffer a lot ,  i have never been  fond of  high lift cams,  too many  valve spring problems seem to  always be arround, but it  sure  should  put the power band  up and into the 6k 6500  rpm range with the cam properly  degree'd in

[Shelby]

after degreeing  my cam on the rr i had to  change the timeing  chain and  grears  at 10k or less to maintain the proper cam specs, but it was  well worth it

 

also a few yr's a go  the boss had an 86  jag with a 400 cid  4bolt chev  v8 ,  nice  cam    carter carb and all,  well  we gain'd  50 hp   just from  degreeing the cam  , and that was new gm parts,  they were off by 24 degrees late brand new, and that chain is many times shorter then our's

[chiplee]

Ok still reading, I just read a post from 1999 with Scott lambson and JJG, Guess John really was tired, he hasn't been back.  anyway the bosch BCFPR I have is a 1:1 unit with an adjustable baseline.  So I'm thinking I need a RRFPR with a 2:1 rate(or more) so I can get out of the Green at idle and get a rise in fuel pressure that more closely matches the increase in airflow that happens when my engine gets on boost.  Any thoughts?  Those regulators are expensive but I think it might add some tunability.  Who has knowledge on the effects of fuel pressure on fuel delivery.  I mean when you change fuel pressure, exactly what changes about the amount of fuel going through and injector.  I know fuel flow varies as the square root of pressure but does that make sense if that's right then this must be right.  Please elaborate or correct as needed.

 

Let's say stock fuel pressure is 38psi

 

Stock supply at 15 psi boost is 38+15=53 psi

 

For 70 psi at 15 psi boost, pressure drop is 70-15=55 psi across injector.

 

Increased flow at 70 psi, vs stock, is sq-rt(55/38}=1.20 or 20%, if injector can handle pressure.

 

so rather than jacking up baseline pressure to say 50 so that a 1:1 gives you 65psi at 15 psi boost I want to maintain stock FP at baseline and increase at 2:1 or whatever it takes to get to the required FP at 15 or 20 psi without exceeding the limit of the injector.

[Shelby]

Chip for some unknow reason  my stock reg is giveing me 40 lbs at idle and 56 at  10 lbs of boost , now with the stock air mass that  gave me two some times slighlty more  green lights,  now with the  1g air mass i got 4 some time 5 leds  green under  10  lb boost , any  reason you can come up with for that

 

and  how does the volume of fuel available in you fuel line effect the pressure drop, like  the amount of fuel in the 8mm lines at x amount of   pressure and the same pressure in  3/8 's or larges lines, and all  turbo'd cars i have ever work'd on had at  least 3/8 fuel lines, these are the first i ever saw with 8mm lines , seems the 3/8's lines should have at least 200%  more fuel in them then the 8mm ones

 

i sure wish those  dyno runs had a fuel pressure   chart on them also, that'd  help

[chiplee]

A fuel pressure graphic would be sweet on dyno runs and very easy to incorporate but then it would just be too perfect a tuning tool and almost worth the $100/hour most of us have to pay so that would be completely out of the question.  Here's a good explaination but I'm not sure if it speaks specifically to your question about pressure drop related to volume of fuel in the lines.  Let me know if it doesn't answer your question. http://www.mcbrooms.com/volvo/injcalcs/injcalcs.htm.  I haven't taken time to sit down and go  through some examples with those formulas yet but they look very simple and very useful so maybe I'll elaborate a bit with some of my own numerical findings later.  I'm tired now.  As far as I know your extra green bars sound ok.  Perhaps the extra air isn't being perfectly metered because of some voltage difference in the MAS.  Never did that mod before the MPI so I have no real good idea man.

[Boosted_One]

More invaluable info from you guys!

 

I spoke with Ross at SDS when I was setting up my MPI and he said they don't recommend running additional regulators. In fact they revommend stock toyota or honda regulators. He said you need to make sure the fuel volume is adequete amd your injectors are large enough and you would increase your map values instead of increasing fuel.

 

http://www.sdsefi.com/techfpr.htm

 

Ross said using an additional regulator is something you would do more to a factory car in which you can;t adjust fuel maps, so you compensate with additional fuel pressure, like we do on the TBI set up.

 

here's another great message board that is SDS. They go thru a lot of tuning situations...

 

http://www.network54.com/Hide/Forum/150383?it=0

 

I am definetely getting a TEP adjustable cam gear this time around also.

 

From what Heffner said his 125psi pump didn't cut the mustard. That is concerning for me seeing his setup is very similar to mine.

 

Tha cam issue concerns me also. What IF the 284 really doesn't cut the mustard. Other than CNM I've never seen a 284F dyno run before. CNM had all day to tune that car so James did pull some tricks out of his hat.

 

Bill TSG lets get some of your input too...

[kev]

Mike,

 

Forgive me for my lack of info on the SDS system (mine is still in the box on my workbench).   How does the ECU change the mechanical timing?   You said you pulled all the weights off of the distributor, you have no vacuum advance, and you have no electronics hooked to the distrib right besides the boost of the MSD?   So what is advancing your spark when you accelerate?  I am not understanding something here.   I can't see how this computer can mechanically change the timing when still using a distributor.

 

Also if your valves start to float at high rpms, you could be getting the back pressure of the exhaust into the cylinders and cause detonation especially on the decent like you were describing.   It might be worth swapping your valve springs, aren't they a few years old by now?  

[chiplee]

Not positive on this Kev but I think Mike and I established that the Hawk and the SDS were similar in this regard.  Maybe not, but in the hawk the distributor works much like a crank trigger for a distributorless setup.  The magna distributor is a hall effect sensor (the hawk can use hall effect or reluctor type).  To time the motor you make two extra marks on the crank pulley.  One at 22deg BTDC and one at 60.  The one at 22 is simply the median of where most engines will run at idle, from 10 to 30 degrees BTDC.  This setting is honestly not very important, the mark could be at 20 degrees and work just as well.  The mark at 60 is so you can reference the position of the trigger in the distributor.   These marks are to the right of the TDC mark as you're looking into the engine bay or too the driver's left, (I know everything in the world rotates counterclockwise from the driver's perspective but hey, these little details help some times, hehe)  So again, to time the motor rotate it to your 22 degree mark, stab the distributor so it's pointing at number 1 and tighten the distributor bolt, you're done!  Now you can back the motor up to the 60 degree mark and make sure the pickup is in the Hall on the distributor,  the dizzy sends a signal to the computer at 60 degrees BTDC saying hey something's about to happen, this gives the computer time to look at the load site and make a decision about how long to wait before it sends a spark.  So if that load site requires 20 degrees advanced it will wait 80 degrees after the trigger and fire.  I don't know how it works if Mike has no electronics going to the distributor except MSD boost.  In fact that sounds impossible.  If the setups are different sorry I wasted your time.  But hey your an engineer so your used to reading endless useless information right.  On that note here's a little elaboration I found on the Hall effect sensor:  The Hall Effect sensor is a magnetic field sensor.  It measures directional magnetic fields and translates it in to a voltage, known as Hall voltage.  The effect is based on charges that move through a semiconductor but the charges are deflected by a magnetic field.  The deflection is caused by the Lorentz force.  The deflection is very small, however it is large enough to create a small voltage, or Hall voltage,  to form along the edge of the semiconductor.

[kev]

Ok so what you are saying is there still has to be some control in the distrib to advance and retard the timing when the computer tells it to do so?   There is no other way you can do it in my mind.   I have the same SDS computer as Mike but unfortunatly I have been too wrapped up in the body work on my blue car and trying to get my white car back on the road that I haven't even been able to think about the blue cars engine for some time.   I just remember Mike saying that everything needs to come out of the Distrib (vac advance, counter weights, etc etc) and I don't recall ever seeing some kind of electronic solenoid that needs to go in there to adv and retard timing.

 

Thanks for the detailed info and yes I am used to reading endless info, hehe.  I wouldn't call it useless though.

 

kev

[chiplee]

Well I didn't mean to make you think there was any thing in the distributor that controlled advance and retard.  The way I understand it the delay determination made by the computer after the 60 degree trigger is the only timing mechanism.  On a side note, I just got off the phone with Schneider Cams and they're going to send me a new 292 for the cost of the core.  about $60, he's also going to send me some single HD springs to try and let me return the dual coils if it works out with the singles.  Gotta advertise when a company stands behind their product like that.

[Joel]

What happens on a Hawk/SDS/Haltech etc is all about the triggers. Same as a stock ECU with timing control (or in our case stock ECU w/ ignition control knock box). The computer see's signals from a trigger (In Mikes case an F1 style trigger with 2 North pole magnets and a hall effect optical sensor). The sensor will report back each trigger.

 

You place a magnet X amount of degrees (On the F1 I believe between 50-70 degrees BTDC) and the other magnet is 180 degrees out. On mine, I will have 3 (one sync south pole magnet) which goes in between the last north pole and TDC. Just gives a tad more accuracy.

 

Now the computer sees the signal and knows the rpm. Based of those two figures, you have adjustability up to ~ 40-45D BTDC. All the computer needs to know is "Where am I" every once in awhile and "How fast am I" from the tach signal. The computer then mathematically "guesses" where to send an ignition spark, and generally is +/- 2-3Deg. of that mark. If you have 3 magnets like me, you more likely to be a TAD more accurate.. but the difference is still maybe 2hp on a good tuning session.

 

The Cam is my concern. I'm ready to not even install the 284H cam I have and go for something else if I'm gonna get pulls to 4k and drop like a rock. I don't care how much boost I was to run (just like Mike K here), your HP output SUCKS, torque is up, but theres still no go fast power (even with a margin of error of a dyno in general). I don't want to have to run REAL high boost to pull some numbers at the track. My goal here (like I'm sure alot of others here) is to indeed pull the most out of the lowest amount of boost possible. Based on Mike's numbers, if a Cam change is needed, to get that same HP we all should be able to change a cam on a pretty stock motor and get within 30HP of his numbers... So really, something is up.

 

As far are fuel pressure is concerned, Mike has his info right from SDS. Fuel pressure is NOT where you want to go. Get your base pressure between 30-45psi. Thats it, No RRFPR or BCFPR. Reason why: Try to tune a good map on variable flowing injectors. Your maps will be F'd. Your injectors flow X amount at 3000RPM, and flow MORE at 5000RPM, as much as a 10-30% difference in a 20psi raise in pressure. Try to make your maps gradiant right now? hehe, not gonna be real easy, so now you have to make a hopping map (goes up and down). Can be done, but almost impossible to get right.

 

I would however do a 1:1 BCFPR like the stock one. Reason: To match the pressures in the manifold. If you increase manifold pressure by 10psi (stock), but leave fuel pressure alone, the pressure differential between the two is going to be less. You will get less fuel flow. Matching pressure to pressure will keep flow even.

 

Joel

[chiplee]

Sounds good on the FP issue, that's why I bring my ideas here first so you guys can squash them before they become wasted money, lol

[kev]

I understand how the hall sensor enables the computer to know the timing and adv/retard it.  However I am running a distributor.  If I had seperate coil packs, the computer will just tell the coils to fire when it wants to and it fires.   However with a distributor, that rotor only contacts the plug wire in one specific spot if all the other mechanisms are gutting in the distributer.   So how can the computer tell it when to fire and when to not fire?  It has no choice, it only fires when that rotor hits the prong in the cap

 

kev

[Joel]

I understand how the hall sensor enables the computer to know the timing and adv/retard it.  However I am running a distributor.  If I had seperate coil packs, the computer will just tell the coils to fire when it wants to and it fires.   However with a distributor, that rotor only contacts the plug wire in one specific spot if all the other mechanisms are gutting in the distributer.   So how can the computer tell it when to fire and when to not fire?  It has no choice, it only fires when that rotor hits the prong in the cap

 

kev

 

I've asked that question many times of SDS and Haltech, both can't tell me how the mechanizm works inside to allow that, but they claim on a distributor you have the same adjustability. Maybe some day I'll find that answer. I still am wondering.

 

Irregardless, thats another reason I'm happy to move to DIS. I don't have to worry about a dist.

 

Joel

[kev]

I've asked that question many times of SDS and Haltech, both can't tell me how the mechanizm works inside to allow that, but they claim on a distributor you have the same adjustability. Maybe some day I'll find that answer. I still am wondering.

 

Irregardless, thats another reason I'm happy to move to DIS. I don't have to worry about a dist.

 

Joel

 

I just sent an email to SDS asking them to clarify this.   I  skimmed the SDS website and I couldn't find any info regarding this subject.   I will have to break out the owners manual for the computer tonight or this weekend and see what it says.   I kinda wish I would have spent the extra $100 for the F system actually.

 

kev

[kev]

Ok I think I figured it out and SDS got back to me and confirmed it.   The distributor is set at one particular spot (i.e. you want it to always fire at the same position (10BTDC, 5BTDC, or whatever).  The hall sensor reads the actual position of the engine, send the signal to the ECU, and the ECU makes sure that the coil provides spark to the distributor when that rotor hits the prong for the certain cylinder.    Thus there is no cheating by mechanically altering the rotor position in the cap, it is all done electrically.   Only drawback to the distributor is you need to initially set it exactly where it needs to spark.  

 

 

Sorry for going off on this subject.  I thought this might have been one of the problems but I guess not.   I think I do like the 'F' system better though.  

 

kev

[Boosted_One]

SDS just uses the distributor. The weights are removed and all you do is phase the rotor.

 

There are no electrical connections to the distributor other than the coil wire. The SDS fires the MSD6A and is triggered via the Hall sensor.

 

The entire timing curve is RPM driven. you set where you want your timing at what RPM level. Under boost you can retard the timing based on your MAP values. You can add a mock vacuum advance under your MAP values.

 

All the distributor is doing is turning with the cam and the rotor is spinning the spark. That's it.

[kev]

Yeah I know we have been through this before.   I thought about this long and hard in the beginning of the year and I proved it to myself that it worked but for some reason it didn't sound right to me this morning.   It takes some thinking to undo the tricks the car manufactures did in the past and to actually think about it the way it "should" be.  

[heefner]

Chip thanks alot for posting that info.  Even if it wasn't your words it's very helpful to all of us.  I would have cut and pasted as well.  I kinda missed my window to reply earlier so I apologize for screwing up the flow.  As for header and turbo exhaust housing affecting hp curve, I agree 100%.  Bill TSG has his TD05 ported as far as possible to allow max flow and is also running the SPF header with great success.  I think the tubo housing has a larger effect although the SPF header does have longer runners.  I have spoke with several people saying that the 20G will not make as much power as a comparable t3/t4 hybrid.  Reason being, flow of the t3/t4 is better on the exhaust side.  The mitsu exaust housing is just too restrictive.  EIP runs t-76, t-66 real big turbos so you can't really compare thier numbers but at the same time they are pushing 450+ with out the juice and shifting at 7200 with basically the same motor that I'm using!  If my turbo ever goes I'm spneding the extra duckets and going t-4 ballbearing and external wasgate.

 

On a side note, incase anyone is wondering, I'm running about 50lb base fuel pressure with a 1:1 increase with semins 72lb er's. I also replaced my supply line wiht a 3/8 line the last time I snaped the u-joint.  My drive shaft crushed the return line so I used the supply as the return and upgrade the new supply line.  

[Boosted_One]

I wonder if this lies in the turbine housing? Hmm

 

Is it time to jump on the Garret wagon?

 

Is it the cam?

 

The valvesprings I run are Schneider HD and were replaced last September with maybe 1500 miles on them

 

Those runs I have posted in this thread are the exact same shortblock, exact turbo, exact cam and head, but different intake and ECU.

 

I've always pointed towards the TBI. I know how to tune a car and it can't be coincidence that the 2 runs look so similar in peak and drop off ranges.

 

I've seen other dyno runs that look like similar to mine. Power drop off after 4-4500.

 

Scratching my head on this one right now.  ???

[Boosted_One]

Ok I think I figured it out and SDS got back to me and confirmed it.   The distributor is set at one particular spot (i.e. you want it to always fire at the same position (10BTDC, 5BTDC, or whatever).  The hall sensor reads the actual position of the engine, send the signal to the ECU, and the ECU makes sure that the coil provides spark to the distributor when that rotor hits the prong for the certain cylinder.    Thus there is no cheating by mechanically altering the rotor position in the cap, it is all done electrically.   Only drawback to the distributor is you need to initially set it exactly where it needs to spark.  

 

 

Sorry for going off on this subject.  I thought this might have been one of the problems but I guess not.   I think I do like the 'F' system better though.  

 

kev

 

You can send your ECU back and they can modify it to run distributor less.

 

The reason I stayed with a distributor is because coil packs can go. I've seen peoples cars that have had problems with that. I have also read some of this in the mags and on the net when the racer is out due to ignition or coil pack problems.

 

Not saying this will happen but look at how many hi-po cars run distributors and never miss a wink.

 

A distributor is mechanical (less mechanical in the SDS), the coil packs are electrical. Both have failures.