Hands on experience with stroker kits?
Originally Posted by erioshi
Currently I'm leaning towards the 2.3 set-up because of the lower piston velocities and lower than stock compression.
Piston velocity and acceleration limits can be set by reducing redline. Longevity is reached almost always by this method and not by reducing stroke and increasing engine speed.
anything under 425 whp would feel very disappointing to me for the money & effort expended. I guess I still need to do more research on turbo set-ups.
I'm familiar with "fixing the driver" first, but at this point I'm looking to get the car to where I can play with the very fastest of my crowd. In general I do tend to be near the top of the pack. The cars I'm chasing are generally on slicks with alot of suspension development and/or have a much better power to weight ratio - and most are also generally either dedicated race cars or super cars. Slicks (instead of my current R compounds) should help quite a bit in the corners and braking zones, but I still need more power for the long, fast straights.
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Shawn@SG - would you please just check out of this thread? You haven't added anything I consider useful in my quest for information. I'm already aware of the "issues" you keep trying to raise and I'm also aware of all the compromises. Your "advise" isn't bringing anything new to the table for me.
Ludikraut - if my car had a torque curve like a normal Evo I'd agree with you 100% about the lower RPMs. However all the head work and large cams have moved the torque curve up and flattened it out; not what I asked for - but it's the head they sent me, lol. My car is now making solid torque in the mid range, but it keeps building to a peak at about 6K with very little taper - and as a result the HP curve builds almost to redline - my optimal power band is the top of the tach. If it wasn't for boost taper the car would be even more "top end" happy.
I think you're right about the 3076 though; although I'm still currious about how a 35R would run if set up a bit tight.
Originally Posted by Ludikraut
I still think you're on the wrong track with the WHP goal. I think the real goal should be a certain level of torque, maintained flat across a range of maybe 3000 rpms, then tapering off. If you do the math, this type of torque curve matches up very well with the stock gearing. So ideally you'd want full boost at or before 3500 rpms, and have it start to taper off around 6500 rpms. If we're talking a stroker engine, then I'd guess that it will be able to spool up a 3076 to hit full boost by 3500 rpms, and with your setup on pump gas you should be able to hold a relatively flat torque curve until 6500 or so.
In my case I actually want my torque curve to be a little bit flatter than it is now, since it would push my shift point(s) from ~8200 rpms up to ~8500 rpms, but with a stroker engine, it would work out fairly well as is. Now, having said that, my torque begins to fall off around 6500 rpms (3071 on a 2.0). Comparing the theoretical airflow between a 2.3l and a 2.0l, I'd expect the 3071 to start falling off around 5600 rpms, so again a 3076 is probably the better choice in your case.
l8r)
In my case I actually want my torque curve to be a little bit flatter than it is now, since it would push my shift point(s) from ~8200 rpms up to ~8500 rpms, but with a stroker engine, it would work out fairly well as is. Now, having said that, my torque begins to fall off around 6500 rpms (3071 on a 2.0). Comparing the theoretical airflow between a 2.3l and a 2.0l, I'd expect the 3071 to start falling off around 5600 rpms, so again a 3076 is probably the better choice in your case.
l8r)
I think you're right about the 3076 though; although I'm still currious about how a 35R would run if set up a bit tight.
Last edited by erioshi; Nov 18, 2005 at 11:12 PM.
Originally Posted by erioshi
Thanks Ludi - Your suggestions hit pretty close to what my digging seems to be showing. While the GT35R (or RL) might give good peaks I am concerned about the overall power and delivery.
That said, I'm also concerned about having a turbo that's too small to keep up with the head and cams that are in the car; the current top end is heavily modified with oversized valves, insane porting (I needed to modify the intake manifold runners to match the head), and big cams. The Piper Rally cams I'm using seemed to out flow the HKS 280s I tested by a noticable bit on the stock (10.5 hotside) turbo; I expect the difference will grow with increased capacity in both flow and engine volume.
Currently I'm leaning towards the 2.3 set-up because of the lower piston velocities and lower than stock compression. I had figured that 500 whp might be optimistic, but I can always hope. I would probably be happy with anything over 450 whp; anything under 425 whp would feel very disappointing to me for the money & effort expended. I guess I still need to do more research on turbo set-ups.
Shaun - I'm familiar with "fixing the driver" first, but at this point I'm looking to get the car to where I can play with the very fastest of my crowd. In general I do tend to be near the top of the pack. The cars I'm chasing are generally on slicks with alot of suspension development and/or have a much better power to weight ratio - and most are also generally either dedicated race cars or super cars. Slicks (instead of my current R compounds) should help quite a bit in the corners and braking zones, but I still need more power for the long, fast straights.
That said, I'm also concerned about having a turbo that's too small to keep up with the head and cams that are in the car; the current top end is heavily modified with oversized valves, insane porting (I needed to modify the intake manifold runners to match the head), and big cams. The Piper Rally cams I'm using seemed to out flow the HKS 280s I tested by a noticable bit on the stock (10.5 hotside) turbo; I expect the difference will grow with increased capacity in both flow and engine volume.
Currently I'm leaning towards the 2.3 set-up because of the lower piston velocities and lower than stock compression. I had figured that 500 whp might be optimistic, but I can always hope. I would probably be happy with anything over 450 whp; anything under 425 whp would feel very disappointing to me for the money & effort expended. I guess I still need to do more research on turbo set-ups.
Shaun - I'm familiar with "fixing the driver" first, but at this point I'm looking to get the car to where I can play with the very fastest of my crowd. In general I do tend to be near the top of the pack. The cars I'm chasing are generally on slicks with alot of suspension development and/or have a much better power to weight ratio - and most are also generally either dedicated race cars or super cars. Slicks (instead of my current R compounds) should help quite a bit in the corners and braking zones, but I still need more power for the long, fast straights.
Not to jack the thread but what Pipers are you running? I just got the Piper Race cams (272's) but at 1mm they are more aggressive then the 280's and was wondering how you like them. I am building a stroker right now.
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I am Running Piper Rally (listed as 265 duration) cams - matched with Ferrera(sp? - too lazy to look right now) dual coil valve springs and 1 mm oversized valves. And some crazy ported head porting.
The Rally cams have about the same duration at 1 mm as a set of HKS 280's but they have more lift on both the intake and exhaust.
The Rally cams have about the same duration at 1 mm as a set of HKS 280's but they have more lift on both the intake and exhaust.
Last edited by erioshi; Nov 18, 2005 at 11:26 PM.
I had a 3076r on my 2.0 and was putting down at least 450whp with no problem. I gatta belive that turbo on a 2.3 would be pretty wicked from 3500 to 8500 rpm. On a 2.0L and a 3076r I had 18lbs of boost by 4200rpm so on a 2.3L 18lbs should be there around 3700 rpm.
I am currently building a 2.3l with Pauter rods, Pauter machined crank(to much to list and -6lbs over stock) and probly going with Wiseco custom piston set built for 8.5 to one compression. I think I will go with the 35r but the 30r would be pretty wicked.
I am currently building a 2.3l with Pauter rods, Pauter machined crank(to much to list and -6lbs over stock) and probly going with Wiseco custom piston set built for 8.5 to one compression. I think I will go with the 35r but the 30r would be pretty wicked.
Last edited by 4ringturncoat; Nov 18, 2005 at 04:37 PM.
Originally Posted by erioshi
Shawn@SG - would you please just check out of this thread? You haven't added anything I consider useful in my quest for information. I'm already aware of the "issues" you keep trying to raise and I'm also aware of all the compromises. Your "advise" isn't bringing anything new to the table for me.
You have disregarded technical points on
1) Service life
2) Compression
3) Piston velocity / acceleration
To not know these issues is only ignorance - easily correctable.
To know them and not act on them is stupid.
These things are very basic and if you do not open your mind and consider these things and take a correct approach to them, you will not even come close to meeting your two already unrealistic and conflicting targets. It seems anything not in line with your rationale, you consider useless. But I assure you, these issues are very real and ignoring them will not make them disappear. You may not want to hear about them from anyone, but it's better to hear them now and consider revising action, or have life teach you the same lesson, just a lot more brutally, later.
Well I can't say I didn't try. So long!
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Ever since the head was rebuild the bottom end torque has been off. I think part of the problem is that they went overboard when they decked the head - another reason I'd like to drop the compression a bit more. I've already moved to a thicker head gasket which has helped some.
Here's a dyno chart from when the car first went back together: https://www.evolutionm.net/forums/sh...6&page=1&pp=15
With more work and a couple of changes I was able to eliminate most of the taper up top while leaving the rest of the curve alone. With less compresion the bottom end should come back.
Here's a dyno chart from when the car first went back together: https://www.evolutionm.net/forums/sh...6&page=1&pp=15
With more work and a couple of changes I was able to eliminate most of the taper up top while leaving the rest of the curve alone. With less compresion the bottom end should come back.
Last edited by erioshi; Nov 20, 2005 at 10:04 PM.
Decking the head would help raise compression, thereby helping out he low/mid range. You probably lost you low/mid range b/c of all the head porting. Big ports=low velocity, going to a stroker will help that.
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Your logic is dead on. Oddly enough though, testing showed (in this case) that lowering the compression ratio made better power all across the board; my guess is that it added back some of the displacement which the aggressive decking job removed.
Tuning the low to mid range required backing off quite a bit as though the car was generating knock. We were never able to log or isolate any knock events, though, so there's a chance we were just trying to tune out engine noise. All in all it was pretty frustrating trying to get the car dialed in right - while I eventually ended up with a decent tune, it always felt like there was a fair amount of power that the existing set-up was just short of being able to tap. The bottom end was asking me to dial things back and the top end wanted more.
Adding displacement to help with the lowered intake velocity is another of the reasons that I'm planing to move to a stroker. Between that and the compression issues I've been fighting I expect that the car should end up running alot better.
Then I just need to match all of that with the right turbo - given the the car's head flow, I suspect that with the right cam timing and a good tune I can balance power delivery and spool well enough to keep decent spool response and still have a turbo that won't taper out on me.
Tuning the low to mid range required backing off quite a bit as though the car was generating knock. We were never able to log or isolate any knock events, though, so there's a chance we were just trying to tune out engine noise. All in all it was pretty frustrating trying to get the car dialed in right - while I eventually ended up with a decent tune, it always felt like there was a fair amount of power that the existing set-up was just short of being able to tap. The bottom end was asking me to dial things back and the top end wanted more.
Adding displacement to help with the lowered intake velocity is another of the reasons that I'm planing to move to a stroker. Between that and the compression issues I've been fighting I expect that the car should end up running alot better.
Then I just need to match all of that with the right turbo - given the the car's head flow, I suspect that with the right cam timing and a good tune I can balance power delivery and spool well enough to keep decent spool response and still have a turbo that won't taper out on me.
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