crcain

Seriously you and the people tuning don't have much experience then. There is not much to it... turn up the boost... pull the timing. Yes the parts matter a lot... but once they are installed just turn up the boost, map the timing curve, and have a proper way for listening to det.

It's you who needs to show us the technical data... show me a GT35R Evo with good parts, on 93 pump, that you raised the boost from 23 to 25 psi and didnt make more power. You are the one that is lacking in technical info.

Ted B

iTrader: (6)

Mike,

Says whom? We would have all said the same things as you only a year ago, because we did (https://www.evolutionm.net/forums/sh...d.php?t=250559).

Like the rest of us, you've been conditioned to be so intimidated by higher boost pressure that you've neglected to remember that ignition advance/retard is what makes it practical or not. I agree with your suggestion for a technical discussion, but that's best done in a new thread. I'm afraid it's simpler than what you're assuming. There's no magic pixie dust involved.

David Buschur

iTrader: (53)

Ted B., I have heard crcain speak of him. You said that everyone here on these boards, including the professional tuners owe a thanks to him and the UK tuners for being able to do this. I am simply pointing out that I didn't know anyone was tuning for this kind of boost on pump gas, meaning I "stumbled" on it myself. From the posts I have made the the comments/following of them I'd say most of the guys here on EVOm have had their eyes opened by the work we have turned out on pump gas and not what's happened in the UK.

crcain, I understand completely what you are saying and don't feel you I saw what the guys in the UK were doing. From what I had seen on MLR I always assumed the 98 oct they were using was much better than anything we had here from the pump so I never paid any attention to their numbers. Add to that everyone of them uses a different dyno, a different type of HP rating and I was never even curious. I see a lot of "slow" cars (they don't concentrate on 1/4 mile) and never thought they were making any power.

We are behind what the UK has been doing with pump gas and I do agree with Ted B. it was a "mind limitation".

Basically we kept pushing the boost another pound or two as I did good builds and pretty soon we found that 28-30 psi was no problem.

Mellon Racing

iTrader: (38)

exactly...with the right combination of parts you'll be amazed at how EASY it is to make big power on pump gas.

I was ~ 400awhp on 93 octane, I literally pulled the 20g turbo off, installed bigger injectors and the HTA 35R kit...nothing else was changed. At 6psi less made the same power. I upped the boost 3-5psi and picked up 60awhp, raised it another 2-3 psi and picked up 40awhp more. All said and done I'm up 135awhp over the evogreen on 93 octane within 30 minutes of installing the turbo.

there's no magic, just the best parts for the job and a good tune makes all the difference in the world.

crcain

Bottom line... I want U2SLO's car

I'm waiting to see what changing from Magnus Race intake mani to HKS does for me. Can't wait to tinker with that and watch my AFR's go super lean once installed. (hoping )

David Buschur

iTrader: (53)

Ted B., give Mike one of those long very technical explanations for me, I can't do it as I don't have the book knowledge. I just know what I see that makes it all work, simple minded is what I am.

gamebred26. The margin of error depends on the build. NOT every car we do can run 30 psi on 93, no way in hell. Some can, some can't. Depends on the build and it depends on the fuel quality. Sorry Mellon, but I do not agree, atleast here in the northern states there is a HUGE difference in pump gas quality. Valero for example is HORRIBLE fuel and will knock like mad. So back to the margin of error. Peter's car for example has quite a bit of timing in it at 30 psi. The knock control is set up aggresively if it does hear any knock, the fuel cut is set to 32 psi, the timing over 31 psi instantly retards very quickly and heavily. So there are many safety features. As a matter of fact I have warned Peter if he races someone or goes to a dyno for a number he CAN NOT run anything over 31 psi or he is going to lose power very fast. The car has been running at 30 psi for a year or so, no problem. Trent's car (our welder at the shop) has gone 10.6 at 134 mph on 93 octane at 30 psi. Same story, no problems. He drives his car 62 miles ONE WAY to work each day.

I am not tuning cars on the edge and waiting for them to blow up, that will NOT bring me more business. It would bring me warranty work, bad press and pissed off customers.

David Buschur

iTrader: (53)

Mellon, we actually put a stock turbo back on Trent's car this week. So we went from our 35r kit to stock turbo. We lost exactly 200 whp just changing turbo kits on pump gas. I was actually going to make a post about it and forgot.

His car ended up at 26 psi when we were done on the stock turbo.

Tracy

iTrader: (1)

I like Ted B whoever that is. Ill read that entire thread later when i have more time.

Ill respond later

gamebred26

iTrader: (19)

no you're not ...you are right....but if you are making 600whp on 93 and 600whp on c16 or meth which same set ups .which one is safer?

i think a good tune for a dd not a race car should leave room for error.

DTM

iTrader: (4)

Your quest for knowledge is downright expected! You have the right to question and ponder how or why something that may not be mainstream is accepted by a group of individual tuner(s), customers or forum members.
With that said, for every exaggerated or legitimate claim, there still needs to be factual and theoretical basis for truth without hype as its main driving source.
The "general" consensus you mention; "20-22 psi is dangerous on pump gas" is not only incorrect but not common practice. Maybe in the honda world or 240 community but not here. But, let me say this, it is not your fault that you were told or taught that theory. In practice we can see that it is a variable that many people do not understand.

The ability to run xx boost pressure has to do with many controlled and dynamic variables. The key point to remember is that airflow and boost pressure are not the same thing. It is a very common misconception. If not the greatest myth in this industry second to exhaust "backpressure."


The ability to run a specific boost pressure is dictated by and not limited to the following:

Turbo (compressor) inlet pressure and temperature
Discharge pressure, velocity and temperature
IC design, flow rate, heat exchange efficiency and outlet velocity
Differential pressure between the throttle blade and the intake plenum.
Charge temperature after the IC and in the engine bay
Type of material used to transfer this charge to the engine components named above
Head: port velocity, valve face and bowl geometry, inlet and exhaust port geometry, flow rate, coolant temp, combustion chamber shape, size and cc.
Cam profile: lift and duration for a given piston speed and engine displacement
Quench area, piston design, static and dynamic compression, rpm, combustion chamber turbulence, flame speed and propagation, injection angle and atomization, fuel droplet size vs air molecule density and how the fuel and air molecules attach to each other.

Ignition lead, quality of the spark, plug gap, cylinder temp, charge temp and air fuel ratio.
Valve overlap and scavenging properties based on the rpm band and the design of the exhaust header.
Turbine nozzle area, exhaust gas velocity, port taper and flow rate, differential pressure between the inlet of the turbo chargers hot side and the discharge area.

And of course the type, design and efficiency of the entire turbocharger.
EDIT I guess I should a competent Tuner!

DB and many other have obviously figured out how to use a combination of parts that make this equation work for them. It really isn't that hard to see.
What many will question, is the reliability associated with the type of fuel being used. Again no one has tested these limits or extremes before so it seems a bit "strange" For those who have seen or tested it it is becoming quite common.

Keep some things in mind here, if you look at the specific vehicles that claim this type of power level, what are the common combination of parts being utilized?
And no the answer (I'm sorry dave) is not ALL BUSCHUR products. It is the right combination of parts as stated many times BY Dave. That is the key. Most of, if not all 4-5 vehicles I have seen and researched have very similar setups. Dave can claim that his parts and his tuning produce those results because they are IN FACT his combination, that he assembled, whether he made them or not, they are producing said results. BUT that does not mean that others have not done the same. He is just smart enough to be different and provide a product that works for him and his customers are happy with the results.

Since 06 when we sponsored a cylinder head for one of our local customers we immediately saw amazing gains with pump gas and one of our hybrid 35's What we were making on pump gas, a blueprinted and ported cylinder head, stock block, and 18 psi of boost was more than previous versions with NO cylinder head work at all. Actually over 55 WHP. At that time 18 psi and 420 WHP on our MD dyno was outstanding. We would not see that number unless we ran alky and 25-26 psi on the same turbo before. Knock was almost extinct. I remember trying to get to the knock threshold of the engine, but instead reached a power loss over any signs of detonation.

Bottom line is that it takes quite a bit of trial and error to get to that point. Maybe Dave finally got there? It seems so.










Mellon, "technical theory" is what a human yearns to have validation. It is a good thing.
Dismissing it is ignorant.

Ted B

iTrader: (6)

By all means, I enjoy reading the results of your testing, and I certainly give credit where it is due. Perhaps the most important point for those who remain skeptical is the results are very real, and this isn't an isolated case.

DTM did it for me, but it need not be so complicated.

Well, one thing to keep in mind is that 600hp is 600hp is 600hp, no matter how you slice it.

LilRico

iTrader: (21)

I would like to see those results so that I can compair it to my car...

Ted B

iTrader: (6)

The simple version . . .

The piston is moving faster than the flame front. The position of the piston (after it crosses TDC) has a direct bearing on what we get in the way of power and EGT, all else being relatively equal. This is important to remember when we think how ignition timing relates to the position of the piston in the bore when max cyl pressure is reached. Max cyl pressure is a factor of static pressure (piston position) and air density (boost pressure) when the charge is ignited.

If our turbo is plenty efficient and of ample size, and we set our boost pressure to let's say 20 psi across the board, we tune to the detonation threshold and record a certain amount of power. At that point, if we advance the timing any further, the limits of pump fuel octane will prevent the piston from being any higher in the bore when max cyl pressure occurs, simply because the fuel becomes unstable when subjected to greater static pressure.

If we raise the boost pressure to 25 psi, we have to retard the timing to adjust to the new detonation threshold, which means that when max cyl pressure is reached, the piston will be a little further down the bore (static pressure slightly reduced). The difference is that at 25 psi, we make more power because the same volume of air in the cylinder is more dense (more O2 molecules), and this offsets the fact that the static cyl pressure is not as great, simply because the piston is a little further from TDC.

As we keep increasing the boost pressure, we will reach a point where the increased air density cannot compensate for the reduction in static pressure, simply because the detonation threshold sets our piston too far down the bore when max cyl pressure is reached. When we get to this point, increasing the boost further and resetting the timing gives no more power, and we see an increase in EGT, because the fuel charge is burning so late in piston travel, that it is still burning when the exhaust valve is opened. We don't want this, so monitoring EGT is a good idea when tuning like this. The unknown here is that where this point occurs will be different according to a variety of physical and mechanical factors. Differences in cams, headwork, intake, exhaust, piston design, turbo particulars etc., will all play a role. For example, if we reduce our static compression ratio (SCR) slightly, we can get away with a bit more boost pressure until we hit this point.

Please understand that this explanation omits numerous variables and aggravating factors. It serves as a simple explanation - an explanation that also illustrates why increasing air density trumps static compression . . . until a practical limit anyway.

I'm on the beach at the present, so no more car talk for me today.

reactionevo8

iTrader: (18)

this thread seems to be causing a little bit of a stir in the other forum i frequent....
http://www.honda-tech.com/zerothread?id=2232979

DTM

iTrader: (4)

I think "Joseph Davis" may need some recalibration ......