What kind of timing advance are you guys running?

I believe the cause was a faulty vacuum line feeding both my boost gauge and my FPR. I will test again this weekend and i'll observe if the pressures stays consistent.

Here's what I posted on FB.

The logging feature on the HKS CAMP2 has come in pretty handy. It has been convenient in troubleshooting a wonky fuel pressure problem i've been having. The last time at the dyno we noticed my fuel pressure was fluctuating a bit and boost was going as high as 10psi (on a CTSC low boost 7psi pulley). This caused us to start chasing the tune. it wasn't that obvious so we thought the fuel pump was dying again. I wanted to shoot myself because I had just swapped fuel pumps last year. My tuner then suspected it could be a bad vacuum hose. I thought it was a bad fuel pressure 1:1 regulator or a weak alternator. (He ended up being correct. I had a vacuum line that rubbed against a pulley and got really thin). All were easy fixes so I went ahead order silicon vacuum hoses, bought a rebuild kit for my FPR and ordered a high output 130amp alternator. I did a few pulls tonight and it seems that may have fixed it. My AFR is solid (tuned rich temporarily for safety) and I ran my fuel pressure about 10psi higher than normal for load testing. Fuel pressure is solid at 64psi at full boost at 7.3psi boost. Back to the dyno I go... sigh.

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I've tuned at least twenty small displacement turbocharged engines, range from 1.6L to 3L, including the famous 2jz-gte and sr20det/rb26dett engines, also 4agze, 4sgte, 1zz.

The ideal way for finding optimal timing is by comparing an EGT vs torque output.

I made this to demonstrate how timing will affect EGT



Because of this relationship, if you can imagine, it is easy to over-time an engine. You will get a low EGT and nearly identical torque with anywhere from 12* to 20* of timing on the same engine (exemplified above). This rule always holds true, you will never add timing and see a rise in EGT at the same air fuel ratio. That is because the sooner you can burn up everything in the cylinder, whatever comes out of the exhaust valves is already cooling, as opposed to a retarded timing advance that allows a still-burning mixture to hit the exhaust manifold, raising EGT. The exception of course being large camshaft duration engines that always spill some of their burning mixture into the exhaust system at lower rpms (in which case you should watch the EGT drop as RPM increases at the same timing advance after 2500~ rpm) In fact, more timing almost always gives a little more torque, so it is easy to add a little extra timing thinking " the engine liked it and my knock sensor is not going off so it must be good ".

The "ideal" timing for a street application is one that is safe for varying road conditions, that leaves head room for going uphill with a bad tank of fuel one dry hot day. The balance of timing and octane with compression ratio and metal composition of the engine can make it difficult to derive exact numbers on paper, however, we have these tools to ensure the safety of our engines.

Another graph showing torque vs timing around peak VE, for the same engine:



What to take away from this
1. too much timing will run an engine "normally" while it eats up rod bearings and possibly takes bits and pieces out of the engine's deck and pistons
2. Set smoothing to "zero" on uncorrected dynojet graphs and look for jagged torque output, that indicates you might have too much timing
3. Ideally you will retard timing until, as the graph shows, EGT begins to climb significantly. At this point torque will also decrease similarly, re-affirming the relationship and letting you know to add a few degrees back and you are done.
4. notice engines with large camshafts can get away with more timing at peak torque areas, this is because cylinder filling is not as good as it was with the stock camshaft profile in that spot, and so Volumetric efficiency is lower, therefore dynamic compression ratio is lower, and more timing is acceptable.

Finally, here is an overlay


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Right now I am waiting for a customer to show up with their 2jz-gte single turbo 240sx for AEM tuning session, so I have another minute to talk about tuning.

I hope you are wondering how air fuel ratio fits into all of this. You can think of the air fuel ratio as a sort of thermostat. If you want everything to get hotter, you take away fuel. An engine will run fairly normally between 11:1 and 16:1 air fuel ratios. In fact I have experimentally run an engine at wide open throttle (22psi of boost) with a 17:1 Air fuel ratio in the past. It did not detonate, it did not stumble or falter. It made a less power than it should have, but only about 15% less. For the most part, you could not tell the engine was in any distress at 17:1. The engine's EGT surpassed the gauges ability to monitor, and the engine withstood SEVEN full WOT passes with this 17:1 before the excessive heat ruined the piston rings. The engine had fully forged internals, which is the only reason the piston itself did not give out on the second pass (an OEM cast piston would not have taken that abuse, this engine had low silicone forged CP brand pistons).

What I took away from the experiment was, the Air fuel ratio being lean by itself will not cause detonation. That engine came apart looking brand new, without a mark on it anywhere, the only thing wrong with it was the piston rings had lost their tension (I could tell initially because at the end of the 7th pass, it burped up a little oil due to blow-by for the first time). I replaced the rings and put it back together and its been running normal ever since (5+ years now, still own it). An engine will routinely burn a lean cylinder in many situations; consider a fuel cut to one cylinder at 7200rpm (factory engines typically incorporate a per-cylinder fuel cut to achieve a soft rev-limter as the engine speed approaches a maximum). On most engines there is a reservoir of fuel available, molecules of gasoline being a volatile liquid with a partial pressure are constantly entering and leaving the air as an engine breathes. A running engine typically has an established "wetness" on the ports/manifold that is available while the engine is running, even if the injector is cut off. Different engines have different designs, this is just an example that illustrates the frequency with which a cylinder is likely to burn "lean" without any damage as a result.

The repeated cycling, the constant frequency of lean burns, that rises temperature over time, is what may eventually lead to engine damage. Having a cylinder that fires 66 times per second, of which only one of those events is allowed to be 17:1 air fuel ratio, should not be a problem. With the increased temperature, you might induce such problems as detonation, however as you saw in my personal example, that an engine may have enough head room (a well designed combustion chamber) for temperature to rise that detonation is not a problem. This is the idea behind water injection and methanol injection, is to lower combustion temperatures (absorb some of the heat with water's high heat capacity) and prevent such situations from causing detonation. Each engine is likely to respond differently to high temperatures, so this is a per-application basis.

Good info. Thanks.

That's at a constant RPM though, which at 4k is, I assume, the peak torque for that particular engine.

From that 4k to redline, however, you could advance that another 2-3 degrees and still be very safe.

Low-load timing is another thing to tackle. Most tuners set this way too low from what I've seen.


My custom turbo'd C30 has a flat torque curve that mimics the OEM from 2750 to 8k RPM - except it is more than doubled. When I built the engine knowing I was going to have it put out 350 ft-lbs of torque to the wheels at 2750 RPM, I ditched the OEM aluminum rod bearings and went to a custom set to give me a bit more margin as I tuned it.

Frankly, I'm not an expert at engine building, and this is the first engine I've ever tuned, but I'm learning a lot and having fun! At least until I destroy it....

BUT, I purchased a used cylinder pressure measurement system so I could see and log the direct cylinder pressure results as a function of timing, AFR, intake manifold, and exhaust manifold design. Well, I haven't done anything yet on the intake manifold (running OEM for now), but I could see big differences in pressure from the exhaust manifold changes. I'm still working on optimizing that. I also only have the single transducer, so I introduce small variances in the ambient conditions when I move it cylinder-cylinder.

One of the neatest things was watching cylinder pressure rise when I went through the process of seating the rings after the rebuild.

Dave

to make a 2D graph like that, I had to hold some variable constant so the rest of the graph could hold true under those conditions.

Low-load tuning is more important in non-turbo applications where you need the engine to accelerate regardless of what is getting thrown into the exhaust manifold.
In a turbo application, I generally under-time the engine, both for safety, and to raise EGT quickly where I need it, it will help "spool" the turbocharger sooner. You can gain some torque at part throttle, just before boost, if you hold the throttle body open just right- but nobody ever does that when they actually drive the car. Usually you just put your foot all the way down and expect the car to get up and go. That is when the load cell zings to the highest pressure sustainable at that RPM by your turbo (if the turbo is large, this is 0PSI) so in a naturally aspirated application I might want 24-34* of timing in this region, but on a turbo application I would probably cut that in half and monitor EGT and compare torque outputs to be sure its helping.

Turbo applications should allow for the airflow to make the power, not try to squeeze it out of the timing advance. if you want more power you just increase boost pressure (is the turbo large enough? If not, upgrade it, do not add timing), no sense in adding timing which could be dangerous if your EGT is not showing any significant improvement after 2500rpm.

With your special pressure recording device, you should see it begin to spike long after optimal timing is attained. Those spikes are what initially cause blown head gaskets on engines that still carry the OEM HG. next is broken piston ring lands, on a stock cast piston engine. I am really curious what sort of numbers you are seeing, I have never had the opportunity to monitor such a device, would you mind posting up the exact details? What pressures, advances, egts, etc... have you recorded? Also, how long did it take to seat the rings? I have heard it happens within 5 miles / 30 minutes.

You've just convinced me to install my EGT probe. Unfortunately I only have one. Any suggestions on which cylinder (in a C30A) is best and how many inches after the heads?

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I've also implemented a Tuning-For-Dummies approach for tuning for driveability. WOT will be left for a dyno session again in the near future. Let me know if anyone finds any issue with this approach. You'll probably notice this is a rudimentary approach compared to an experts approach. I'm happy to admit i'm far from an expert.

I believe most stand-alone ECUs have a AFR compensation program in one way or another. The HKS F-Con VPro i'm using has a 32x32 main fuel map and several 16x16 submaps. I've setup the AF Feedback program to a target AFR anywhere from 14.7 to 11.5 at any given cell. It writes changes to the Submap1 table at increments of max 10% adjustments. I hope to work my way down to 5% and ultimately i'm considering leaving it on permanently at 2%. I then drop in those changes into the main fuel table. I smoothen out any high/low peaks and then zero out the submap1 table. The last step is to renew the Injector map tables... - Rinse and repeat. I suppose, in a way this acts like a Short term/Long term fuel trim adjustment. I can target AF Feedback adjustments on the Fuel tables, Throttle, and a few other ones I don't quite understand yet. The only thing I can imagine going wrong is if my WB O2 sensor goes to shit and sends false readings. However, at this point the changes would be limited to 10% at a time.

The HKS documentation isn't readily available to consumers so I have problems understanding what each feature on my EMS does. The book has got to be 5 inches thick. I'm left to researching the little available data online or asking my tuner (Jon, you are amazing, buddy. Thank you).

This process seems like a no-brainer. Does anyone use this? What are the pros/cons?

I have to admit.. i'm at 2 cycles of this so far and the driveability has improved noticeably. Especially in throttle response, smoothness, and seems a little quicker to boost. This could just be my imagination too.

the closer to the valve you can get, the more accurate the reading, since heat is emitted into the environment rapidly once it is released from the combustion chamber, you are lowering your reading the longer you wait to detect the temperature. If you take a reading at the turbine, for instance, cars that have ceramic coatings, wrappings, shielding, anything that helps to keep heat trapped in the exhaust stream, will help give you a better reading at your probe. I mention the turbine because if tapping the exhaust manifold is not an option, it is very easy to tap an O2 sensor plug for the EGT probe and add it temporarily for tuning. Speaking of which, Anything you can do to keep the heat in the exhaust system will generally improve performance, since hot exhaust moves faster because it takes up more space (there is more space between gas molecules as the temperature rises) which increases its velocity in the same diameter tube which will help FILL the cylinders (due to exhaust gas scavenging effects) on a naturally aspirated engine. On a turbocharged engine, however, the best thing is a wide open exhaust system, basically an open downpipe will give you the fastest "spool" characteristic in my experience, which is why I would recommend a cut-out on the OEM exhaust systems of many cars, to keep noise levels at non-existance until you hit the switch for best torque line all else being equal). I should mention, the only danger of trapping heat in the exhaust system is the risk of overheating the materials (some manifolds will not tolerate constant high EGT without warping) so be sure to use quality materials, and proper bracing to support the turbocharger.

Air fuel ratio is of course implemented in fuel economy during normal driving. Your ideal target is 14.7->15.2:1 while you drive on the highway and around town. Set your widebands analog output so that 15.2:1 is .002v and 14.7:1 is 1.002v and you will achieve 2-6% better fuel economy than if using the original narrowband sensor. Most engines shall generally only dip into the 13.5's once it is approaching 2" of Hg (almost to 0psi). and about 13.2 at 0psi for an engine sitting at 100%Volumetric efficiency and 9:1 static compression is a good starting point on 93 octane with modern combustion chamber designs. Some engines will even maintain a 14.5:1 in this region so these are just guidelines, but you will almost never see 12.9:1 or richer until 1psi or more (boost pressure) unless the engine is a 10:1 compression Naturally aspirated V8 then I would want to see 12.5:1 at 0psi.


For those of you less experienced with turbochargers, and attempting to grasp the effect temperature has, let me just be simple and clear. You want the compressor side to be as cold as possible. And you want the exhaust side to be receiving exhaust gas that is as close to as hot as it was when it left the exhaust valve as possible.

The "cold" side of the turbo is responsible for moving air molecules into the engine's throttle body, where colder, denser air is desired. When you take your car to the dyno, and you want to see its top performance, you cover the compressor side and intake pipe with bags of ice and let the engine off to cool for a while before starting it and making a pass. Turbo chargers can only move a volume of air, the calculations you see online in lb/min which correlate to horsepower (on a compressor map) are derived from formulas that assume air is maintaining a specific temperature, and not changing. As air going through the compressor gets hotter, it's potential for peak horsepower is diminished. More rapidly, the smaller the turbocharger.
The "hot" side of the turbocharger (the exhaust wheel) thrives on the hot, spacious exhaust gas (remember, as air gets hotter, the air molecules move farther apart) so wrap, coat, and shield it well.

Separate the two sides the best you can. Use a turbine blanket and wrapping and coatings as discussed on the exhaust side. On the cold side, fabricate a shiny aluminum shield that separates the two sides, and bring air from the coldest place you can, very well filtered air I should add. Always use an air filter, a large enough one. You can measure the effectiveness of an air filter by measuring the pressure in the turbocharger inlet plumbing before it reaches the compressor if you are ambitious, using a very sensitive gauge with small increments to compare to the atmosphere (MILJOCO LP2507L240 Pressure Gauge, 0 to 60H2O, 2-1/2In, 1/4In) The more vacuum signal you find in front of the compressor the more restrictive the air filter. Although some vacuum is desirable, because this is generally the only place to achieve a PCV during boost, so route this light vacuum signal to the valve cover to take advantage of the pressure drop here. Use a catch can if oil vapor products bother you (or you can be creative with the way you handle solidifying vapor product, by using bends or convolutions like the OEM does on some rubber inlets)

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Here is an actual example of an engine running, boosting, cruising at low speeds (no highway logging) with logged air fuel ratios that are acceptable.
key: LEFT SIDE:
1000 = -13.2psi (27" Hg)
10000 = 0psi
20000 = 14.5psi
TOP = RPM

Notice the engine touches 12:1 around 13psi of boost and I will have it at 11.5:1 from 15+psi on the log, the wideband at the tailpipe on the dynojet will read 11.8:1 In fact, here is a video
of the car running at the dyno
,

kingtal0n said:

to make a 2D graph like that, I had to hold some variable constant so the rest of the graph could hold true under those conditions.

Click to expand...

Right, I was trying to confirm for others that you chose the 4k to plot because it probably coincided with your torque peak on that particular engine. Timing effect is typically optimized at the engine torque peak (due to the combustion efficiency and intake/exhaust volumetric efficiency from that particular engine), and from there, advanced a few more degrees until engine redline.

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kingtal0n said:

Low-load tuning is more important in non-turbo applications where you need the engine to accelerate regardless of what is getting thrown into the exhaust manifold.

In a turbo application, I generally under-time the engine, both for safety, and to raise EGT quickly where I need it, it will help "spool" the turbocharger sooner.

Click to expand...

No, because low-load tuning is important for fuel economy and engine responsiveness. A lot of people like that kick-in-the-pants when they mash the gas... wait a second for the engine to acknowledge you want to accelerate, then wait another second or two for the boost to build... and then off you go. Or, they just don't know better and have been brainwashed into accepting this lousy driveability in exchange for greater peak output. Sure, you may have great peak dyno numbers, but that is no fun for a street vehicle.

I tuned my low-load timing according to efficiency and responsiveness. Sure, I might have a little detonation at times, but this mild detonation will not hurt my engine with forged, ceramic-coated internals. My EMS is set to quickly retard timing in this scenario. Off-boost responsiveness is important, that is also why I built my FI'd engine with the OEM 10.2:1 static CR instead of reducing it as might be done for typical big builds.

Significantly changing the combustion chamber and volume with the piston dome shape was not something I wanted to get into. I felt more comfortable keeping with the old-tech design and improving on it. Every engine build on here I saved the head pics and piston pics so I could analyze them for combustion patterns. They were consistent, so I used Mr. McFarlands ideas to improve them slightly with enhanced squish pads, piston and head dimpling, and mild head re-welding. Nothing major, but I feel these did allow me to reduce the timing and resulting negative torque a bit from an un-altered engine to give me a bit more power.

I can see on other builds where you reduce the piston dish or increase it how it will have major effects on the timing the engine wants, and the overall combustion efficiency. That's why I feel the high-compression pistons are not very good for these engines, and neither are the low-compression pistons, and why you should never decrease CR by increasing HG thickness. Of course, I don't have a dyno queen with big numbers to brag about.

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kingtal0n said:

Turbo applications should allow for the airflow to make the power, not try to squeeze it out of the timing advance. if you want more power you just increase boost pressure (is the turbo large enough? If not, upgrade it, do not add timing), no sense in adding timing which could be dangerous if your EGT is not showing any significant improvement after 2500rpm.

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It's all about balance, and is why I have a lot of respect for the OEM engineers. If I want big power, sure, I could just increase boost and accept more lag etc. That's not what I'm into... a combination of efficiency, responsiveness, and power.

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kingtal0n said:

With your special pressure recording device, you should see it begin to spike long after optimal timing is attained. Those spikes are what initially cause blown head gaskets on engines that still carry the OEM HG. next is broken piston ring lands, on a stock cast piston engine. I am really curious what sort of numbers you are seeing, I have never had the opportunity to monitor such a device, would you mind posting up the exact details? What pressures, advances, egts, etc... have you recorded? Also, how long did it take to seat the rings? I have heard it happens within 5 miles / 30 minutes.

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It sounds like you have the knowledge and capability to make something like this on your own. You can buy the sensors from Optrand and then set up a high-speed data acquisition system (I used to use the National Instruments when I was in the labs) with your CPS output. You can also log your EGT output and boost pressure, and whatever else has a 4-20mA or 0-5V output. I would also recommend tapping into your knock sensor(s) too so you can look at the actual output traces instead of relying on det cans. Here's an example of the NSX knock sensor traces:
http://webpages.charter.net/eddyanm/traces2.html

Or, you can do what I did and wait for a used single kit to come up for sale. Mine is a TFX kit. Very nice.

As far as seating the rings, after the first start and warmup to get rid of the assembly lube and 30wt non-detergent oil, I changed it with JG break-in oil and took it on the street. With successively harder and longer pulls and deceleration runs, it took a short time. It will vary of course since I was monitoring a lot of things (and traffic), but it took less than an hour. I have the "XX" ring package from Wiseco and forget what standard finish Dan Benson put on the sleeve walls.

I think when you wrote "low load" I was thinking "low RPM load". We want a full complement of timing advance at or around 2400~2800rpm to maximize fuel economy and part throttle drivability, 100% true. If you fight for your economy, you also gain part throttle performance, whether on or off boost, and it will help keep the plugs clean. However anything below 2400~rpm is per engine specific, so no general guidelines can be set. I personally watch all of my data, and depending how the engine is being used, and how long I have to sit and analyze that data, I make small adjustments that I can record (do not just plug numbers and watch the knock count). Engines will run "fine" with the wrong timing numbers, so you must be aware of all tuning instruments while making adjustments, and look for results. If you do not see only positive results from added timing, then you cannot be sure it was a healthy choice. I think that the occasional detonation you have is a warning sign you might be overdoing it. If I was in that situation, I would perform a few experiments.
Experiment recommended:

1. Reduce timing across the board by 8* btdc in your off-boost, part throttle, and cruise areas. Use a closed loop system for A/F control.
Drive the car for 150-300 miles and record average injector duty cycle while cruising at constant speeds in this areas.
2. Now add your original timing back, and repeat your 150-300 miles of similar driving.

Did your average injector duty cycles drop significantly when adding back the timing? If not, the additional timing is unnecessary.
To put it another way: If you can't tell the difference by SOTP "feeling", if you dont see any improvements to economy, if nothing seems to change (except perhaps your occasional knocking goes away), you probably do not need the extra timing.


As to "low RPM load", I stand behind my statement that safety is number one. When the engine rpm is 1200 and the user puts his foot down, you can bet there is only 9-16* btdc of timing in that region on most if not all of the engines I tune.
probably best to share a picture, a picture is worth more for this discussion,



So for my "low LOAD" you can see there is substantial advance where it counts for economy and drivability reasons.
But for "low RPM LOAD" meaning high load, low rpm, I have significantly reduced timing numbers. The engine doesn't need it, in this case, I can run an extra 15* everywhere and it still gives me back the same exact torque output and engine response. That is a sign the additional advance is unwanted, unnecessary.

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It's all about balance, and is why I have a lot of respect for the OEM engineers. If I want big power, sure, I could just increase boost and accept more lag etc. That's not what I'm into... a combination of efficiency, responsiveness, and power.

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So this is an interesting subject, because it is actually somewhat out of our control. To gain power, big power, you must increase the turbocharger size. You can fiddle around with advance and A/F ratio all day for +/- 50 horsepower, but if you want 600 horses from a 2L engine there is no way to maintain a "balance" of response, you simply need too much turbo. Its up to the owner to decide how they wish to utilize their engine's displacement, but that is what you really are saying, that you, as the owner, prefer a turbo sized small enough to maintain that balance. If you found yourself 150 horses short of a goal and your turbo is out of breath, you have no other option than to upgrade; adding advance and playing with fuel quality is not going to add 150 horses. (You could spray, though...) OEM Engineers hopefully give us something that will go 200,000 miles and is easy enough to maintain, and that everybody can enjoy driving, and I too respect that and read the FSM before making any physical changes to my engine to get "the right idea". If you want more response and power you generally need to increase displacement, or find a better turbocharger design.

Thanks for the information regarding the device you use, I will look into it, but I am pretty poor so it is out of my reach presently. Actually as of today a ham sandwich is out of reach... so yeah

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Right, I was trying to confirm for others that you chose the 4k to plot because it probably coincided with your torque peak on that particular engine. Timing effect is typically optimized at the engine torque peak (due to the combustion efficiency and intake/exhaust volumetric efficiency from that particular engine), and from there, advanced a few more degrees until engine redline.

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This is also interesting, I have read a few times that best brake specific fuel consumption occurs at peak torque, and I believe it.
This peak torque is your "max injector on-time" but not "max injector duty cycle" figuring out why is the first step to understanding fuelunits/time and how it correlates to peak horsepower later.

Also, you don't need to increase timing to redline on many engines, if they have a large camshaft and maintain a flat torque curve. Like this one,


Timing generally follows Volumetric efficiency once engine RPM is past 2500~ so if VE is falling after peak torque... you add timing. If VE remains constant, most of the time, leave the timing flat as well. You hear all the time that engines " need more because of engine speed and burn rates " but in my experience this has not been the case and I am starting to think it was just somebody's myth that "sounds right" and if you look at an OEM timing map you see the extra timing and think "they did it so it must be right". But take a step back and realize the OEM map accounts for failing VE as the stock camshaft robs the cylinder at higher rpm.

To put it another way, how much timing " would need to be added " from 4000 to 6000 rpm? What about 6000+? And is the additional timing added in a linear fashion or is there a differential involved with the rate of expanding gasses after a certain RPM, that depends on the shape and design of the combustion chamber? Or even the particular blend of fuel you are using (not all 93 is the same).

It sounds like a bunch of UN-solvable math to me, so instead, I might add a few *degrees on the dyno IF torque is falling off, just to see what happens. If torque is not falling off, (like above in my little picture), then why would you add timing? If anything I would be pulling it out to see if my torque stays the same, and re-confirm that was a smart move by watching the EGT stay put as well.

I appreciate the time and information you've put into your posts and i want to clarify that i am not trying to advocate advancing timing as much as possible.

Consistent to what you've written, i try to put my timing where it results in optimum cylinder pressure and timing relative to the power stroke. Too much timing results in the negative torque. In my previous post i described the combustion chamber mods i made specifically to reduce my timing yet optimize burn. Ive read a lot of Dave Vizard and Jim McFarlands works to help me understand the combustion process... I'm no expert but have tried to apply their balanced approach in my build.

Oh, and my FI build is a custom semi-sequential semi-compounded twin turbo setup. No lag, instant response, and flat torque from 2700 to 7500 rpm.

Mac Attack said:

Ive read a lot of Dave Vizard and Jim McFarlands works

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+1 David Vizard !

I was reading his works when I was 15, before I even owned a car. I had the entire exhaust system planned out on my imaginary Camaro before even owning one. I would put my foot down, shift, and imagine the exhaust gas scavenging in my head that would improve my Volumetric efficiency during overlap... I grew up around V8s, carb'd engines, I took apart at least ten different Holley 750s, I know there are 144~ adjustments but only ever found about 7 of them lol. I had a blowers on a small block chevy, twin turbo with home-made manifolds before they were available a dime a dozen from ebay. I was running the prototype commander 950 software engine management from Holley when it first came out, and made a few improvements, even implemented an auto-tuner for it by writing a small piece in Visual Basic. The only engine I ever destroyed was an 86' 2-piece rear main seal 355 chevy motor, I drilled the lifter valley for a roller lifter retainer plate, with the engine in the car, and got metal shavings in the oil (I was about 17 years old and did not understand the importance of keeping a clean engine yet). I spun every bearing in that engine, you know when you cut a piece of aluminum pipe with a chop saw, how all that mangled aluminum hangs off the side? Yeah.

<3 cars, keep it safe and simple, I do this to take a break from homework/study (I am a bioengineering student) thank you for sharing my main goal is to share what I've learned to make others lives better. Also I have no job, and soon I will need one to keep living, so if anybody is in the CIA or any Race car team I would like to work there. Or baseball

Good for you! Keep working hard in bioengineering and you'll get there.

Dave

You've got a bright future. Keep it up!