Hello, please go back and re-read the post along this thread about the rule structure and weight breaks.

Flow (power) potential is fixed by valve area.

 

https://www.evolutionm.net/forums/sh...7&postcount=68

If you take a look at his response to your previous question about this, he mentions that drag racing rules comes into play when these shops pick their displacement size. Also, please note that a drag car might be the "fastest 4G63 cars" in the 1/4 mile, but that is nowhere near being the same as the "fastest 4G63 track car in the world".

It's nice to see that you understand his perspective though since some still dont see the correlation between making the same power at 7000 rpm and 8500 rpm equates to less stress on the 7000rpm engine...

Terry S

 

Drag racing rules allow them to use a 2.4L, 2.3L, 2.2L etc. They CHOSE to use the stock block and crank (2.0L). I know Passante from Magnus runs a 2.4L in his 9 second 2G DSM, but he is only one example, and he is not in the top 5. However, its common knowledge that you can run whatever stroke you want. Im not talking about a track car, I never was, we were talking about power I thought. (road course I assume u meant), Im talking straight up drag race 1/4. Power is the name of the game and the big guys choose the 2.0L because of its high revving capabilities, that is how I understand it to be.

On the other note, I can understand obvoius things like the stress points and what not. However, if the limit of the stroker is 8000 and the 2.0 can go well over to 9000, it may be possible for the 2.0L to make more power at these high RPMs . Remember, Glazer's 2.0L is going to 10,250RPM!!!!!

Again this is just 1/4 drag racing. I know obvoiusly real-world driving and roll racing that the 2.4L is by far the best choice, and if my motor ever blows, it will become a stroker.

 

Well, the only reason why I was linking that to tracking a car is because the original poster had commented that he was "more into ciruct racing my car over drag racing". Revving high is great for huge power numbers and drag racing, but as it has been said over and over by all sides in this thread and others, faster spoolup of the turbo and a larger power band makes things much easier for road racing/auto-xing.

Also, since the original poster was concerned about longevity, Shaun was suggesting the stroker motor not only for the more track friendly powerband, but since the car will be making power quicker and with less revs, it should effectively last longer. (refer to his example for details)

Terry S

 

Ok well if thats the name of the game, Id also say stroker is the way to go 100%. However in the other argument over power potential, I believe the 2.0L is the best. POWER DRAG RACE- 2.0, everything else, stroker!!

 

The NDRA rules add weight based on displacement. Weight breaks have been discussed in the post that Terry S has brought up.

It is selected because the rules allow the 2.0 to run lighter. The power can be made up by revving it higher, but wear is exponential for a given RPM increase. An illustration has been made in the post Terry S has mentioned. It is called a weight break and is present in most classes of drag racing. Go look up the NDRA site.

As the numbers have shown, and as authoritative literature says, this is not so.

Free of rules, I would take a 2.4 on the road, AND I would take a 2.4 to the drag strip.

The professional drag racers want to race for class wins. Class wins bring sponsorship and advertizing revenue, reputation, hence business. But class rules also impose limitations on what you can or cannot do and the professional drag racers have to play by the rules. It is no use setting the world record for ET and MPH, when your setup is totally different (lone ranger running 2.5 litre, nitro fuelled, etc.) . The rules are to keep costs down and to level the field so the winner can rightly say "We all played by the same rules, but I came out on top and WON because I understand engine dynamics and know exactly how to optimize for any setup, even under any limitation imposed by the rules [which everyone plays by].

 

There are no minimum displacement limits in the NDRA Pro ranks. Why not destroke the engine to a 1.2 litre and rev it higher, and make more power? Since everyone is so in love with tiny strokes and high RPM and big power.. destroke it! By Umiami's logic, it will dominate the field. It is not weight penalized.

 

See, thats exactly the reason why there needs to be a racing league that has almost no rules. As long as it doesn't directly attack the other racers, the track, or the spectators, it should be allowed....

Terry S

 

That would be nice to see, especially in road racing.

 

lots of information in this thread, thanks.

 

i've learned a lot more about engines by reading this entire thread... the golden rule is: there's no replacement for displacement

 

Thank you Speedlimit.

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And now that we can proceed rationally at least for a couple days..

Does anyone know what the quickest (ET) or fastest (MPH) open class 4G63 in the world is? Or top 5 or 10? By open class I mean that it is not a car that competes in a drag class penalizes displacement by adding weight to the car. Ideally it would be a car that run without nitrous too since, as explained in post 68 of this thread, nitrous removes any oxygen flow limit in the heads.

I am asking because if it is found that there are no fast open class stroker 4G63s around, then it leads to other questions. These questions are definitely pertinent..

1) Are the stroker drag 4G63s slower because the engine is, counter to physics, inherently less powerful? OR is it because the teams that race in the most watched and contested classes (NDRA, NHRA, etc.), have the most sponsorship/advertizing money, and have the cashflow to run business, make more money off that, and then put it into development work on the 2.0s that they run? In other words, are the economic/business forces inherent in racing, and the rule structure of rule limited racing, overwhelming the advantages (that some, including I, see) in stroker 4G63s?

2) Is there any record of drag racing stroker 4G63s that have come, failed, and gone? Could it be that the average enthusiast who strokes the engine properly is interested mainly or only in road racing?

===========

Separately, what are the weaknesses of a properly built 2.3 or 2.4 stroker?

I have read a little of the tuner views on this issue, but there is nothing solid. Burschur criticizes the Toda kit saying it will not hold more than 7500RPM because of the stock 2.4 rods. This is understandable because looking at it, they are real thin. He also says there have been errors made in stroker kits in the past and that there have been redesigns and he is waiting to see how these new ones perform. AMS hints mysteriously at 2.4 strokers having a certain problem, but never really says what. RnR who sell 2.4 strokers voice displeasure with AMS's mysterious claim. Strangely enough, AMS sells 2.3 stroker kits, so are we supposed to understand that, according to AMS, up to 2.3 there is 0 problem, but crossing just 100c over into 2.4 territory suddenly problems pop up? Am I supposed to trust someone who has made glaring errors in fundamentals like the order of detonation leading to pre-ignition, or the definition of 'end-gas'?

Workshop politics is why I do not listen to anything they say unless the point purely by itself, carries logic. I also pay no attention to weak insinuations or hints at problems. I believe that people that have something to say should be forthright about it and say it straight.

So let's discuss about strokers and use our own observation and logic.




for the record and temporary holding I wish to say 260 vs 297 kgf. It makes no sense now but might come into discussion in the future. Also, 1.33

 

I believe the main reasons the big Evo drag racers stick with the 2.0 is due to gearing and the reliability of the 2.0 at high RPM's. With stock Evo gearing, a racer that is trapping 145mph+ needs around 9000rpm in 4th. Most stroker kits are not proven at these levels on Evo's. But....TRE is coming out w/ some taller ratio's which may turn most of these hardcore races to the stroker kits.

 

Hi JJ.. can't the stroker guys upshift to 5th? Or does it cost them too much time? I didn't look up the NDRA rules on transmissions, but what kind do they run? Thanks

 

I think that the taller gears offered by TRE will be a huge benifit to people running a stroker engine.

One of the reasons a 2.0 reving to 9500 RPM is a good drag setup is because of torque multiplication and it's effects on acceleration. In other words, the longer you stay in a lower gear the better you accelerate. The new TRE gear set will give better spacing for a car with a motor biased towards more torque. It will be able to take advantage of these taller gears better than a motor biased towards high RPM power. The new gear set will still work well with the 2.0 guys, but it will be even better for the stroked motor cars. They list speed in each gear at 7,500 RPM and 9,500 RPM.... advertising for both stroker and 2.0 guys

Keith