Thanks Terry S and Wrench.

I'm done with umiami and ploki. If anyone wants further clarification on a point already discussed, or to discuss new points logically, I will be happy to resume discussion. Till then, take care and have fun!

I remain open to the possibility of being wrong in what I have learned and continue to see happening in the race world, but there has to be solid logic and proof opposing what I currently hold true, else I cannot take it seriously. Discussion has to be logical in order to progress. Let's all progress!

 

Well to attempt to pick up the original theme...

I believe that most "tuning groups" have been sticking with the theme of stroking an engine for track use and just keeping the 2.0 displacement but beefing up the internals for drag use. This fits inline with what you were saying as I read it.

A perfect example of this is AMS recent entry into the One Lap of America race where they took their drag car (beefed up 2.0 as I recall) and stroked it so they would have the instant boost responce needed for track events.

Terry S

 

Mayn!!! i left this thread for a good day, and all this flaming?? ANyway, its good for you guyz to argue bcuz ppl learn from it. But fighting over who's right or not and calling names is not cool . This thread was meant to be answered and hopefully benefit from it.

Guyz chill the fawk out!!! lol

i do appreciate the post here, dont get me wrong. But i want it civil please....heheh

Anyway....shaun...you mention to me about teh CROWER 2.3-2.4l KIT.....what makes this better than the jun 2.2l stroker kit. Jun is a respected manufacture as far as engine blocks and head modding goes. They have test lab that consist of test benches especially for teh 4g63. I have read articles on the kit and alot of import tuners has been recommending me to go this route. But i really dont want to go to any details, i am currently still reaseching abot the kit as far as specifications and history goes. The 4g63 has been around and its potential still exist as one of the best. So it is really obvious for me to see facts than fiction.
If you have time, i would really appreciate it if you could school me on the crower kit. Then i will compare it with jun kit.

Thanks

 

I too would like to hear as much about the Crower vs Jun debate.....

I really like the fact the the Crower crank can be ordered with a 102MM stroke...

If you are going for the most displacement wouldn't you go with Crower.....

 

I was talking about the crank actually - it having a large stroke. Being a billet piece, plus Crower having a history of building custom cranks, one would think the crank would be of sufficiently high quality.

I do not doubt that the Jun piece is just as good or better in terms of quality. It yields less displacement for a similar bore size though. Bore size should already be maximized no matter what stroke you pick, for valve area, unshrouding, and squish & quench, benefits.

If you find that both companies are about equal in terms of reputation for performance and have the factory or community support that you need, then all that is left is to select one based on pricing and availability.

Best of luck!

 

Remember the 2 FASTEST & QUICKEST DSMs (both using 4G63) in the world...woth run 8s @ 165+ BOTH have 2.0L. Since we're on an EVO forum, so does Dynoflash and I believe Turbotrix does too!

If I had the money and choice, yes Id build a stroker because for me its the best choice as I drive a lot and do roll-on racing... however for all out drag race car ... 2.0L is unbeatable.

Here is a dyno of Extreme's AWD Race Talon 2.0L - Can you say 10,250RPM!!!! This run is without the N20. They say their crank HP with the N20 is 1125HP. Now THATS impressive.

 

You have to look carefully at drag racing class rules and consider them when you want to try and decipher why the teams are running a certain combination that is not optimal. This is analogous to seeing inefficient aerodynamic designs in F1 and LMP cars, not because the teams don't know what they are doing, but because the rules force them into a compromise. I believe this is what you are seeing in some of the top forms of 4G63 drag racing.

In many of the NDRA Pro classes, you are forced to add weight based on engine displacement. Remember however, that power potential is determined not by displacement but mainly by valve area. With a turbocharged engine other main factors are fuel qualities, compressor and intercooler efficiency.

So we have..

1) Valve area
2) Compressor and intercooler efficiency
3) Fuel

The teams are more or less equal on 1 because they will run whichever block (bore) and head (valve area) combination allows them the best flow potential. NDRA specifies stock of aftermarket non-billet blocks, so the selection is quite limited. On 2 naturally they are at max efficiency given the rules. NDRA specifies maximum turbo size for a class. Fuel selection is limited by the NDRA and again the teams run the best. Because of all this near equality in all the main factors that determine power output, it follows that power output will be roughly the same no matter what the displacement, except for difference in efficiencies (mechanical, thermal, volumetric [1 and 2 relate heavily to this])

IF flow limit is reached for any reason (and there are a multitude of reasons), the engine is inducting an absolutely fixed air mass and so how much power it makes is dependent on how efficiently it can burn the fuel with this air mass. In such case, the stroker engine with its lower surface to volume ratio (thermal efficiency) and lower revving, lower friction (mechanical efficiency) WILL send more power to the wheels because it is not suffering as much friction loss. At the RPM, combustion pressures, components masses, and engine geometry these drag 4G63s run, the additional power should be in the 20hp range. We will name this flow limited scenario, scenario A.

On the other hand, if flow limit is not reached, then the 2.0 is free to turn even higher RPM to flow disproportionately more air mass in order to overcome the inefficiency and send equivalent power to the wheels. Wear is increased, BSFC (an average of all the efficiencies in an engine) is also increased (a negative thing). Thankfully, in drag racing, these two factors are not a concern since teardown intervals are miscroscopic and fuelling only needs to be for a 1/4 mile. The opposite is true in most forms of road racing - especially endurance road racing. We will name this NON flow limited scenario, scenario B.

We will use 1000hp as a nice round number in the following examples, especially since the top teams run roughly that much power. The rules are taken from the NDRA rulebook for the Pro RWD class which I understand some of the quickest and fastest 4G63s run in. Rules in other classes may be slightly different, but hopefully the explanation here allows you to see how teams are forced to evolve according to the rules, and not necessarily to what is actually the best.





Scenario A (Flow limited)

Based on the min weight rule of 1800lbs and 0.80lb for every cc of engine displacement, and using stock 2.0 and stroker 2.4 as examples, teams are faced with the choice...

1) Run a 2.0T 1800lb car with 1000hp
2) Run a 2.4T 1920lb car with 1020hp

By going stroker, you have gained 120lb, but only picked up 20hp. Not good at all. The harder a car can accelerate, the more gain mass reduction yields. Option 1 is selected.

The teams would like to run LESS displacement so they can drop more weight and increase power to weight ratio, but the min weight rule prevents that.



Scenario B (Non flow limited)

Based on the min weight rule of 1800lbs and 0.80lb for every cc of engine displacement, and using stock 2.0 and stroker 2.4 as examples, teams are faced with the choice...

1) Run a 2.0T 1800lb car with 1000hp
2) Run a 2.4T 1920lb car with 1000hp

By going stroker, you have gained weight, but not gained any power. This is even worse than scenario A. Option 1 is still better, and is selected. The engine is therefore required to rev high and sacrifice longevity and efficiency in order to get to the best power to weight ratio and WIN the drags.






So it can be seen that if the rules did not exist, the stroker engine would make more power, and last longer. Remeber that on our personal cars, of for cars joining open class competition, there are little to no rules. Don't handicap yourself unnecessarily just because you want to without understanding, ape what the fast drag racers are doing. Rules try to create equality be it to keep costs down, or to keep the racing close and exciting. Sometimes the rule makers lack understanding of engine dynamics and set up rules that do not accomplish much and only narrow the choices that racers have because it favors one combination so much. I'm not saying that is what has happened in the NDRA, just talking about rules in general. If you were to study the rulebooks of different forms of racing in different countries, different classes, you would see it all the time.


ElectricBlue.. as privateer road racer, you DO have concerns about longevity, about efficiency, and about price. You also are NOT limited by class rules (unless you intend to go racing in some restrictive class you haven't told me about). Look to air restricted application racing or endurance racing to see what is best for efficiency and longevity. Read up on why the BMW M3 GTR evolved to 4L V8, and how it right away started beating the cars that used to beat it, how the Corvette C5Rs evolved from 6L to 7L variants in order to stay competitive (and eventually win multiple times!), how restrictor plate Nextel Cup cars are always at the displacement limit set by the rules, etc. So many examples exist in the racing world, where ever you look with a discerning and earnest eye. Where are the examples to the contrary? Why can no good and official examples be produced? Why is it that those who produce these weak personal examples are always spiteful and angry, lacking logic?

 

According to this page.. http://www.dsmtimes.org/fastest.htm , the large majority of top 10 4G63 drag racers run nitrous. For this majority, this effectively removes the possibility of scenario A described in the post above (essentially an oxygen induction limit), because nitrous is so oxygen dense that you just spray more to flow the desired amount of oxygen that will meet combustion requirements of the power target.

This is stronger motivation to stay with a 2.0T powered car - one that suffers no weight penalty. Stress the small engine to the extreme (high RPM, high MEP), run the lightest car, yet make the same power as a 2.4T, win the race. Suffer the huge wear on the engine...pay to win really. The question is.. how many of you can afford to pay as much as a pro drag racing team? How many of you can deal with drag racing power delivery (narrow band monster power) on a road course or on the street?

 

check it out guy everone here has given you great advice but honestly call one of these shops up who has a reputation with the kind of drivng you wanna do and ask them. so if circuit time is in your future, AMS might not be the way to go. call around if there are as good as they advertize they should be able to tell you the basics of what they can do for you over the phone. and its just on you to go to the shop and spend your hard earned cash on makeing your evo how you want it


just my 2c's

 

"...friction does not go up with crankshaft speed in a straight line relationship. Inertia loads - rotating and reciprocating - are speed squared, and power loss with inertia is friction times speed. Speed squared times speed is speed cubed." - John Judd

There are some components of friction on an engine running with all its accesories that increase roughly linearly X^1, whilst some increase at X^2, still others like above subject to inertia load increase as a cube of engine speed X^3. I have heard from someone who has connections at Ilmor that the overall losses come out to just under X^2. This of course will vary between engine types and operating speeds. It is, however, consistently agreed upon by all the main engineering texts, that it is on the high side, far from linear.

Bottom line remains... to keep inertial load, frictional losses (and hence wear) down, keep crankshaft/engine speed low. For these reasons as well as surface area to volume ratios mentioned earlier, the most efficient reciprocating piston engines (50-55% energy converted to crankshaft power) in the world are the largest in displacement, lowest in RPM (100+RPM), and the lowest specific outputs (3-4hp/litre).

 

Sounds like Shaun knows what the hell he is talking about and umiami just likes to argue till he's blue in the face. Umiami, it sounds like you are trying to compare a daily driven (aggresively) Honda motor's reliability to an engine that is in races. No comparison. Shaun is correct 100%. This is very comical reading umiami's post.

Shaun, what is it you do for a living?

 

Hey look, you got the last post, well almost....

 

 

Stock 1997cc

Bore---------------------------------------------------- 3.346"
Stroke-------------------------------------------------- 3.464"
Redline------------------------------------------------- 8500 RPM
Volumetric flow at 100% VE*---------------------- 300 CFM

Mean piston speed---------------------------------- 4772 FPM
Peak piston speed----------------------------------- 8035 FPM

Peak piston acceleration [TDC (tension) ]------- 4597 G
Piston acceleration at BDC-------------------------- 2512 G



Stroker 2370cc

Bore---------------------------------------------------- 3.385"
Stroke-------------------------------------------------- 4.016"
Redline------------------------------------------------- 7168 RPM
Volumetric flow at 100% VE*---------------------- 300 CFM

Mean piston speed---------------------------------- 4664 FPM
Peak piston speed----------------------------------- 7996 FPM

Peak piston acceleration [TDC (tension) ]------- 3974 G
Piston acceleration at BDC-------------------------- 1884 G




*100% value for ease of calculation. Flowrate equalized between both examples, meaning same fuel mass burnt per unit time, so energy release in combustion chamber is equal. How much makes it to the crankshaft is dependent on the operational characteristics of the engines. It can be seen that for a similar mass burn rate, the 2.0 performs worse.

1) Mean piston speed on the 2.0 is higher by 2%
2) Peak piston acceleration on the 2.0 is higher by 16% at TDC, 34% at BDC.
3) Not only is the engine experiencing these higher loads, but it is experiencing them at a rate faster by 18% . Finite cycle life of all components is being used up quicker.

Power for power the stroker does not need to rev as high, experiences lower inertial loads at a lower rate, and so it lives longer.

 

Thats a nice argument but.... Your saying one engine is going to live longer on a basis of how much interia load it has at a given rate? A motor's life can depend on a million or more variables. This is only one of them. It makes complete sense, but I still dont completely understand why if what you say is true then how come the fastest 4G63 cars in the world all run the 2.0. Shep is over 2 years on the same block at insane boost levels and nitrous. I just feel that if the 2.4L was the better stroke to use (power AND reliability) that John Shepherd and Sean Glazer would both be running it in their 8 second awd 4G63s, but their not, and no one is making near the power they are on a 2.4. I'd like to hear one of them chime in or maybe even Dave Buschur?