What has greater power range

[TT_NS]

What set up do you think has a greater power range? a 2.3 Stroker with a FP3575 or a 2.0 with a FP3575. I was thinken about it because you cant rev as high with the 2.3L yet you spool up quicker but with the 2.0 you acan get higher revs and but take longer to spool.

 

[andymoraitis]

While the stroker has less high RPM capability, the amount of torque that you pick up is massive at the onset of boost. Having driven and owned both motors, the 2.3 is something I highly prefer over the 2.0, and even with a small turbo like mine it makes for an exceptionally fun street car. With the right turbo (like the FP you're looking at) it would make for an absolute beast.

Being able to rev high has it's advantages, but torque is the grunt that gets you moving and I wouldn't trade it for anything.

Just my .02,

Andy

 

[crunchymilk]

not to mention with the right equipment, strokers can still rev decently high.

but the added airflow by the 2.3 makes it almost always better than a 2.0

 

[TSisleeper]

hope this helps... 2.4L

(www.hahnracecraft.com) HRC super 25G turbo (like FP3575)
RC Engineering 720 cc injectors
VRS 3" s/s o2 elim turbo back
no cat
HRC electric boost controler
(11:1 on w/b o2 @ 26 psi on 100 oct. GT RACE fuel @ sunoco)
4gcs 2.4L block
4g63 head (no port work)
Forrester intake man.
3" bbk throttle body
brp9es ngk plugs
B/R coil on plug with MSD dis 2
arp studs and ralli art gasket
victory performance street fmic with 2.5" pipes
tial 50mm bov
pacesetter tubular turbo manifold
aeromotive fpr with walbro 255 high press pump
koyo rad. with twin electric fans
AEM EMS w/ zeitronics w/b o2
act 2900 with fidanza 8lb flywheel
shep stage 2 FWD trans

341 fwhp / 358 fw trq with 330+ trq from 3900-7100 (7100 redline)

my buddies set up on his 91 laser rs FWD, I'm sure with some port work and a better tune his car would hit 400 whp, or am I mistaken ?

 

[Slippi84]

not to mention with the right equipment, strokers can still rev decently high.

but the added airflow by the 2.3 makes it almost always better than a 2.0

They're both right but this isn't a good comparison unless you knwo where you would rev to with each like if you plan on staying at stock rev limiter with both of course it's gonna be the stroker but if your reving to 8500 with the 2.0l and 7500max with the stroker then you have your self a descision to make.

 

[TT_NS]

They're both right but this isn't a good comparison unless you knwo where you would rev to with each like if you plan on staying at stock rev limiter with both of course it's gonna be the stroker but if your reving to 8500 with the 2.0l and 7500max with the stroker then you have your self a descision to make.

that is exactly what im saying. What do you think creates the best power range? to me it seems that the 2.3 would be better since it gets you off the line a whole lot quicker. My favorit saying "its not how fast you go its how fast you get there".

 

[snox135]

They are both good power ranges. But you have to decide if you want more low end torque and shift at a lower rpm or give up some torque and shift higher.

Just remember that spining a 2.3/2.4 at 7800 has a higher piston speed than any production car made right now (including the new RS4). A F1 motor averages ~25 mps during a race, max is ~ 40 mps at redline. A 2.4 at 7800 is 26 mps. Piston speeds that high do have a great effect on reliablity.

 

[Turbocharged]

341 fwhp / 358 fw trq with 330+ trq from 3900-7100 (7100 redline)

my buddies set up on his 91 laser rs FWD, I'm sure with some port work and a better tune his car would hit 400 whp, or am I mistaken ?

Is he on stock cams? Cams and some water injection would get him there no problem.


Your "power range" will depend on many variables. A 2.3/2.4 really shines when its supported with the correct mods.

 

[Slippi84]

Is he on stock cams? Cams and some water injection would get him there no problem.


Your "power range" will depend on many variables. A 2.3/2.4 really shines when its supported with the correct mods.

Is this a street car ? If so I wouldn't run a 2.0l with it cause no matter what spool will suck ass.

 

[Turbocharged]

Is this a street car ? If so I wouldn't run a 2.0l with it cause no matter what spool will suck ass.

Can you explain what you are talking about?

 

[Slippi84]

Can you explain what you are talking about?

Well withou a buil engine with higher compression you won't see full boost in a 2.0l with full supporting mods and cams till 4500+ and i just won't be fun. In a word LAG which is the enemey of all dd's

 

[Turbocharged]

Well withou a buil engine with higher compression you won't see full boost in a 2.0l with full supporting mods and cams till 4500+ and i just won't be fun. In a word LAG which is the enemey of all dd's

I get 21psi by 3,300 rpm running a 2.4L, 50 trim, and comp 101200's (fp2). Im confident I could run a much larger turbo and still see full boost near 4,000 rpms. Cams really dont hurt lag as much as people think. People who have problems with cams usually dont have them degreed correctly.

 

[MrPikolo]

What set up do you think has a greater power range? a 2.3 Stroker with a FP3575 or a 2.0 with a FP3575. I was thinken about it because you cant rev as high with the 2.3L yet you spool up quicker but with the 2.0 you acan get higher revs and but take longer to spool.

What kind of power are you looking for? This would probably help us best.

 

[Slippi84]

I get 21psi by 3,300 rpm running a 2.4L, 50 trim, and comp 101200's (fp2). Im confident I could run a much larger turbo and still see full boost near 4,000 rpms. Cams really dont hurt lag as much as people think. People who have problems with cams usually dont have them degreed correctly.

One comps cams don't give up that much low end compared to ther cams. I was gonna pick up a pair of comp's from Percision and he said he actually spooled fast with the

ANyway you have a stroker the spool I was talkin about liek I said is with a 2.0l. A stroker is suposed to decrease spool 20% or so. In a nut shell add 3-400 and that's the average diffrence between the two in spool. If you already have a stroker and it's not broke why change just get the fp3575 and be happy



Edit: Nvm your not the original poster. WHy what do you think he shoudl do then????

 

[TT_NS]

the goal for the engine would be around 600hp

 

[TT_NS]

I found this http://www.dsmtuners.com/forums/showthread.php?t=203475 this guy talks about the fp3575. this is obviously on a 2.0. would it be more useful to keep it as a 2.0 instead of the 2.3 Im thinking of it this way. with a 2.0 the power range is 4800-9500RPM's with a 2.3 4000-7500 what do you guys think? (give or take 500RPM's)

 

[TSisleeper]

what's up guys just leaving some more helpful (hopefully) information. my personal street car is a 2.0 with a 20G, I know this isn't near a 3575 by any means but just wanted to add to the conversation in regaurds to the cam selection. I just had the comp cams race grind # 101300 put into the car and holy sh*t they are amazing. Not just like I see a nice improvement like in 3rd gear at 45-50 mph I stand on it and litterally roast the front tires easily, I mean VERY easily. just saying the comps are awsome for less then 500. wish I would have done it sooner

 

[Turbocharged]

I found this http://www.dsmtuners.com/forums/showthread.php?t=203475 this guy talks about the fp3575. this is obviously on a 2.0. would it be more useful to keep it as a 2.0 instead of the 2.3 Im thinking of it this way. with a 2.0 the power range is 4800-9500RPM's with a 2.3 4000-7500 what do you guys think? (give or take 500RPM's)

If you are trying to build a car similar to evil eagle's, you may want to talk to him about it. I believe he was initially running a 2.3L but was having issues with crankshafts breaking. If 600 hp is your goal, either get the eagle racing 100mm crankshaft for a 2.3/2.4 build or go with a 2.0.

And again, if you use the right parts, both engines will have nice "power ranges". A 2.3/2.4 will be more fun to drive on the street.

The only reason I brought up the cam issue is that larger displacement motors tend to respond better to aggressive cams and can increase the power band through a wide range of rpms. My car starts to die off around 7,300 rpms but there is plenty of power at lower rpms.

 

[steel_3d]

Would it be more useful to keep it as a 2.0 instead of the 2.3 Im thinking of it this way. with a 2.0 the power range is 4800-9500RPM's with a 2.3 4000-7500 what do you guys think? (give or take 500RPM's)

This 7500rpm magic number everyone throws around is not what you think it is. It's a safe number, not a ceiling.

A 2.0 spinning at 9500 has the same piston speed as a stroker spinning at 88/100*9500 = 8360rpm. (At least average piston speed, I can't calculate max acceleration right now, I'm at work ).

[EDIT] I did in fact calculate the difference in redline based on piston acceleration in <a href="http://www.dsmtuners.com/forums/showpost.php?p=50445180&postcount=105">Post #105</a>. There's only about a 3.3% difference in redline if you only look at acceleration. At this time I can't think of other quantifyable factors. The difference in the structural integrity of the two cranks is probably one.

So don't think that at 7500 a stroker is hurting as much as a 2.0 at 9500. If you're willing to spin your 2.0 to 9500 you should be willing to spin your stroker past 8000. There's a few other issues besides piston speed, but it's a decent indicator.

There's this little issue of a crappier rod ratio, but it doesn't seem to be a huge deal since there's people who have been spinning strokers to 9000-9500. There's tweaks to the bottom end necessary to do it reliably. Read some of Kiggly's posts here and on nabr. Doesn't seem to have much to do with rod/stroke ratio, just keeping the bearings alive.

Assuming you're willing to go to the same piston speed with either combination, the two setups should have about the same area under the curve = same time down the track.

Think of the area under your power curve as a rectangle. Horizontal length is rpm's and height is power. We know that the area of a rectangle is its length times height.

[2.0] (L*1.15)*H = L*(H*1.15) [stroker]

The rpm band of the 2.0 is ~15 percent longer (lower piston speed) but the power curve of the 2.3 is about 15% higher (larger displacement). It doesn't matter where you put that 15%, it's all multipication.

[edit] I've realized that this oversimplification only works with a flat power curve. For example, if you had a flat torque curve, your power would be steadily rising to redline. In that case you would gain more than 15% of the area under the power curve by extending the rpm band by 15%. In most cases though the torque curve is dwindling by that point, so the flat power curve approximation I think applies.

Actually I believe the torque increase of a stroker at a given rpm might actually be more than just the displacement difference (~15%). Not only are you burning 15% more air/fuel mixture, but the lever arm on the crank is also ~15% longer, increasing torque by 15% on top of that ! (The actual lever arm difference is 50mm/44mm = 13.6%). Of course 15% more mixture assumes that your head/intake/turbo can keep up and deliver 15% more mixture when the stroker piston is trying to suck 15% more, which is not always true, but close enough.

[EDIT] Actually this is wrong, and I'm double counting. To find out why, read <a href="http://www.dsmtuners.com/forums/showpost.php?p=50419543&postcount=83">post #83</a>.

I think I have to say this again. Do NOT confuse the length of the lever arm and equate it to the larger displacement. Its effect comes in addition to the displacement.

If you had a normal 2.0 motor with an 88mm stroke and crammed 15% more mixture in it (higher boost and/or better VE), you would get ~15% more torque.

Now take the stroker, which has a 100mm stroke. Since you still have that 15% more mixture burning, but that same force is now pushing on a longer lever arm, you get more leverage = more torque. Same airflow as the beefed up 2.0, but more torque.

End of rant.


In short, there's 3 main issues:

1. Because of issues other than piston speed, you might not be willing to spin a stroker to quite the same piston speed as a 2.0. On the other hand you can also go higher with the right setup.
2. Because of intake and exhaust restrictions, a stroker might not consume exactly 15% more mixture than a 2.0 at a given rpm. Stroker cams might help.
3. But you get a definite increase in torque from the longer lever arm of the stroker, on top of all that. Of course, 15% more torque at a given rpm = 15% more hp at that rpm.

So a stroker might or might not lose a bit of area under the curve on 1 and 2 (depends on your setup), but it definitely gains on 3.

How you're gonna handle all that torque, I don't know. But you asked about area under the curve, and in my opinion the stroker wins there.

 

[Tom N]

If you are having a problem with lag then learn to down shift.
I dont care what anyone says. High reving 2.0ltrs are still the fastest out there.
I will stick with high compression 2.0ltrs myself.

 

[TT_NS]

This 7500rpm magic number everyone throws around is not what you think it is. It's a safe number, not a ceiling...

you leave allot to think about. I get the oppression that the 2.3L will be more beneficiary to us since it will create more torque off the line but yet has a tendency to not last so long.

 

[bwhughey]

So the "7500" number is "magic" because that's what the stock ECU rev limit is set to.

Again, HP is all about airflow. Increasing stroke gives you the same flow at lower RPM. As was mentioned, stroking also gives you higher piston momentums, as well as higher energies (the latter being of some consequence). It's really the energy that's the problem at higher RPM, because at the bottom of the stroke, you don't have any compression chamber dynamics in which to dissipate, and energy is half the mass times the velocity SQUARED. Yeah, it's rough on bearings.

So the compromise, and there's always a compromise to any mod, is that stroking does place far more strain on the crank and everything attached to it. The question is, is it better to have a 2.4 running at 7000 RPM or a 2.0 stroke at 8400? They both would provide (roughly) the same airflow. My guess is that the stroker is going to have to have beefier everything, or lighter everything, or both, for the same power. Which is why when the old V8 guys talk about a "stroker" motor, they're referring to a SHORTER stroke that they can rev higher.

Can you go fast with a longer stroke? Sure. Is it more "streetable"? Maybe. Like the previous poster pointed out, however, the guys who chase 9's tend not to go that direction because a piston-sized hole in your oil pan can ruin your whole day.

Regards,

Brad

 

[steel_3d]

Again, HP is all about airflow.

I disagree. Higher compression will give you more power for the same airflow than low compression. Also, the longer lever arm effect of the stroker will give you more power per airflow (which is what I was trying to explain in my previous post, maybe I still wasn't clear enough...).

The question is, is it better to have a 2.4 running at 7000 RPM or a 2.0 stroke at 8400? They both would provide (roughly) the same airflow. My guess is that the stroker is going to have to have beefier everything, or lighter everything, or both, for the same power.

Yes they would provide (rougly) the same airflow.
No, the stroker won't need beefy anything at 7k. If you meant well over that, then yes.
No, the stroker will make more power under the curve (very likely).

Which is why when the old V8 guys talk about a "stroker" motor, they're referring to a SHORTER stroke that they can rev higher.

Actually no, "stroker" in v8-land is still longer stroke. Like a "383 stroker" is a long stroke version of a 350. I've never seen it used in reference to a shortened stroke motor.

Didn't mean to tear you up, just wanted to clear up some stuff. Hope it didn't sound that way

 

[bwhughey]

Nope, not going to let you snipe and run. Even though I only log in here about twice a month, whether I need to or not. ;-)

I disagree. Higher compression will give you more power for the same airflow than low compression. Also, the longer lever arm effect of the stroker will give you more power per airflow (which is what I was trying to explain in my previous post, maybe I still wasn't clear enough...).

(edited for brevity)

Didn't mean to tear you up, just wanted to clear up some stuff. Hope it didn't sound that way

You were clear enough. I'll try to reciprocate your civility.

People confuse torque or "lever action" with power all the time; they are NOT the same thing. In fact, one could argue successfully that the distance delta between crank center and rod journal center should be added to the final drive ratio just to normalize the value. Torque, in other words, is simply a measure of FORCE, not power, and your transmission ratios should be selected appropriately. You have gears. Use them wisely.

You're correct about compression (it only serves to decrease BSFC, but it's moot to the discussion). ALL OTHER THINGS BEING EQUAL, the higher compression, as long as it's not TOO high, will effect a more complete combustion and, therefore, more power from the charge.

We're back into the age-old debate about displacement vs. forced induction. If you take so many CFM of air and mix it in the right ratio with so much fuel, and burn it properly, it just simply doesn't matter how many cylinders, cubic inches, bore size, other engine parameters ad nauseum.

You're also correct in that I mis-spoke. V8 RACERS (not street rod people) DESTROKE their motors and twist them to 10KRPM. The stroker guys, with normally aspirated motors, can only do one thing to move more air (after removing the restrictions to flow) - increase displacement. If this increases stroke, it will decrease reliability ALL OTHER THINGS BEING EQUAL. Which is why the guys at ARP, Crower et.al. have jobs.

Why do truck motors have long strokes? It makes transmission design easier (and cheaper). Why do car companies use truck motors DESTROKED in sports cars (like the original Starion, Viper, etc.)? Because shorter stroke is more reliable and can turn a higher RPM. Look at all the exotics - very short stroke motors that in some cases redline at 12K.

Look, if you want to stroke your motor go for it. If you do it right, you'll have more torque and better low RPM throttle response. For me, I'll just get a bigger intercooler and turn the boost up 3-4 PSI. Which approach will be more cost-effective and reliable?

Don't listen to me. Call someone who has run 10's and who doesn't sell stroker kits. Call someone who races Pro Rally and doesn't sell stroker kits. Call AMS. Call Road Race. Call Buschur.

Regards,

Brad

 

[steel_3d]

I'm not out to convince anyone to run a stroker. I just want to keep the concepts clear. I still disagree with some of your statements

People confuse torque or "lever action" with power all the time; they are NOT the same thing. In fact, one could argue successfully that the distance delta between crank center and rod journal center should be added to the final drive ratio just to normalize the value. Torque, in other words, is simply a measure of FORCE, not power, and your transmission ratios should be selected appropriately. You have gears. Use them wisely.

I think we all agree that horsepower = torque * rpm / 5250.
This means increasing the torque at a given rpm by 15% increases the power at the same rpm by 15%. Integrating over the whole rpm range, a 15% increase in torque at all rpm's increases the area under the torque curve by 15% and the area under the power curve by 15%.

Measuring horsepower has nothing to do with final drive or any sort of gearing. You don't need to "normalize" anything. A 15% torque increase at the crank is a 15% torque increase at the wheels (minus the effect of any changing friction). Gear systems and lever systems work on simple ratios. 15% on one side is 15% on the other side.

It's the area under the horsepower curve that gets you down the track faster. The only thing gearing can change is to put you in the fattest part of the horsepower curve throughout the quarter mile. If you had a perfectly flat horsepower curve, it wouldn't matter what your gearing was, you'd always go down the track in the same amount of time (disregarding wheel spin). If you had 15% more torque = 15% more power everywhere in your flat power band, you'd go 15% faster down the track, no matter how you changed your gearing.

You are right in that if you have 15% more power in a stroker, but a 15% shorter power band, you'll end up in the same place by raising your final drive by 15%. The main issue I'm trying to point out is that a stroker with 15% more displacement will have 1.15*1.136 ~ <b>30% more torque and power than a 2.0</b> (1.136 is the ratio of the 2.4 vs. 2.0 lever arm). Even if you shorten the rpm band by 15%, you're still on top.

Again, strokers are NOT just 15-20% bigger in one direction. It's more than that.

Think of the piston pushing on the crank as a 1lb weight on a rod, 1ft form the fulcrum. It gives 1lbft torque around the fulcrum. Now place that weight 2ft from the fulcrum, you have 2lbft of torque. Where would you rather push on a breaker bar, 1ft away or 2ft away or 10ft away? That's what the stroker is all about.