Ls2 408 stroker
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From: Coast of San Mateo County Between Pacifica & HMB
Bortous,
Looking forward to your new results. I would expect your peak to be ~+500 RPM &+12-15 Peak VS current Peak and 20+ @ 7000.
I think a lot of people don't consider the increase in plenum volume the mid-length runners give VS standard length which
really helps with the longer stroke as well. I know that the LOD and other intakes can out perform the FAST mid-length,
but for the price and fitment since you already have the FAST and the ability to change back and forth between street/strip is a
pretty good deal imo.
Looking forward to your new results. I would expect your peak to be ~+500 RPM &+12-15 Peak VS current Peak and 20+ @ 7000.
I think a lot of people don't consider the increase in plenum volume the mid-length runners give VS standard length which
really helps with the longer stroke as well. I know that the LOD and other intakes can out perform the FAST mid-length,
but for the price and fitment since you already have the FAST and the ability to change back and forth between street/strip is a
pretty good deal imo.
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Bortous,
Looking forward to your new results. I would expect your peak to be ~+500 RPM &+12-15 Peak VS current Peak and 20+ @ 7000.
I think a lot of people don't consider the increase in plenum volume the mid-length runners give VS standard length which
really helps with the longer stroke as well. I know that the LOD and other intakes can out perform the FAST mid-length,
but for the price and fitment since you already have the FAST and the ability to change back and forth between street/strip is a
pretty good deal imo.
Looking forward to your new results. I would expect your peak to be ~+500 RPM &+12-15 Peak VS current Peak and 20+ @ 7000.
I think a lot of people don't consider the increase in plenum volume the mid-length runners give VS standard length which
really helps with the longer stroke as well. I know that the LOD and other intakes can out perform the FAST mid-length,
but for the price and fitment since you already have the FAST and the ability to change back and forth between street/strip is a
pretty good deal imo.
You are right about the plenum volume.
Even in the photo it does appear that you do get significantly more compared to the long runners.
I'm hoping for the engine to reach peak power close to 7000rpm and hold it for another 300-500rpm after.
With the camshaft specs I have it shouldn't be an issue.
If there is still a restriction I will most likely upgrade to the new fast tunnel ram intake but I may have to change camshaft again because with these intakes you need an earlier ivc and later Evo.
So something like a 242/256 110lsa+4
Will see what happens
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It will finally be available within the next 30 days.
I contacted fast and they will reserve one for me at a discounted price.
I would also have to cut my hood to get it to fit.
The standard trumpets it comes with are good to 8000rpm
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From: Coast of San Mateo County Between Pacifica & HMB
It literally took years between showing the interchangeable runners
until they were available though.
Will we be seeing graphs to compare with the mid-lengths soon?
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I'm expecting one tomorrow.
I am not sure if i will have a Dyno sheet of the run with the long runners but there will be one with the overlay from the previous run for sure with the older 236/244 camshaft.
As soon as I have the sheets I will post here in this thread.
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Everyone, Let me begin by saying I am more pissed off than last time.
This is a **** news post.
An unexpected issue has come about once again and I have a dyno sheet to show.
Engine was dynoed today with the FAST mid length runners and we still have the same issue.
The engine is still not making any more power and is flat lining after 6000rpm.
After some discussion with my engine builder the only issue it could be is either valve train instability or the heads are not flowing enough.
We are both confident it's the head cylinders.
They were done years ago by a hand porter and who really knows how good his work is.
This engine should be singing smoothly to around 7500rpm with the mid length runners and with max torque torque hitting at about 6000rpm+ and holidng on for another 500rpm or so.
Instead we are bottlenecked.
The heads are going to be taken off and sent to Higgins Race heads.
His CNC program was developed by Darin Morgan too.
We will see if they can be cnc ported depending on how much material was taken off beforehand.
If not I will need to get a new set of heads.
What do you guys think of the curve? Remember to take off around 500rpm or so off the power band due to the converter.
To me it looks crappy.
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If it is valvetrain it is the smoothest looking valvetrain instability I have ever seen.
Looks to me like it hit peak power at 6800 rpm give or take.
Now, if we consider the heads, you are making about as much power as the LPE 660 heads will make to the tires.
I recommend aftermarket heads over re-re-reworking your current heads.
Looks to me like it hit peak power at 6800 rpm give or take.
Now, if we consider the heads, you are making about as much power as the LPE 660 heads will make to the tires.
I recommend aftermarket heads over re-re-reworking your current heads.
It looks like your torque peaked at about 5200RPM and power peaked at 6800RPM. That's to be expected with your combo. The problem is that it's all very low. 550Nm is what, about 405ft-lbs of torque? From a 408? My money says you have a dead cylinder or two.
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If it is valvetrain it is the smoothest looking valvetrain instability I have ever seen.
Looks to me like it hit peak power at 6800 rpm give or take.
Now, if we consider the heads, you are making about as much power as the LPE 660 heads will make to the tires.
I recommend aftermarket heads over re-re-reworking your current heads.
Looks to me like it hit peak power at 6800 rpm give or take.
Now, if we consider the heads, you are making about as much power as the LPE 660 heads will make to the tires.
I recommend aftermarket heads over re-re-reworking your current heads.
Can you even read the power figure?
I don't even know the figure!
The torque figure is still falling off at 5500rpm where it was the long runners.
It definitely should be.
Tuner said it may be valve float but I don't think so.
All other curves I have seen with the mid length runners had very broad and flat curves.
Will find out some more information tomorrow hopefully.
Originally Posted by bortous
Darth, that's what I thought, it's not valvetrain instability.
Can you even read the power figure?
I don't even know the figure!
The torque figure is still falling off at 5500rpm where it was the long runners.
It definitely should be.
Tuner said it may be valve float but I don't think so.
All other curves I have seen with the mid length runners had very broad and flat curves.
Will find out some more information tomorrow hopefully.
Can you even read the power figure?
I don't even know the figure!
The torque figure is still falling off at 5500rpm where it was the long runners.
It definitely should be.
Tuner said it may be valve float but I don't think so.
All other curves I have seen with the mid length runners had very broad and flat curves.
Will find out some more information tomorrow hopefully.
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Damn I just realised it too I am way down on power....
Before it was on 372rwkw.
Something is definitely wrong here.
My tuner also stated that this larger stick did not do much in bleeding off compression.Because of it, he cannot run much timing even on e85.
Compression is at 13:1.1 as confirmed today. It's too high.
And yes it may be a dead cylinder or two. Who knows...
I need to lower compression to around the 12:1.1 area too I think.
I will report back here when I find out more information.
What a **** up
Before it was on 372rwkw.
Something is definitely wrong here.
My tuner also stated that this larger stick did not do much in bleeding off compression.Because of it, he cannot run much timing even on e85.
Compression is at 13:1.1 as confirmed today. It's too high.
And yes it may be a dead cylinder or two. Who knows...
I need to lower compression to around the 12:1.1 area too I think.
I will report back here when I find out more information.
What a **** up
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[QUOTE=spanks13;20143718]Your tuner is taking you for a ride I wouldn’t want to be on.
13:1 is fine on E85 some go much higher.
I’d stop throwing parts at it until you can confirm what’s wrong.[/QUOTE
His a pretty honest guy.
Something else is wrong that needs to be found asap.
That's what I thought too about e85
And yeah the issue definitely needs to be found first.
13:1 is fine on E85 some go much higher.
I’d stop throwing parts at it until you can confirm what’s wrong.[/QUOTE
His a pretty honest guy.
Something else is wrong that needs to be found asap.
That's what I thought too about e85
And yeah the issue definitely needs to be found first.
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An update.
Compression test was done.
All good.
No dead cylinders here.
One issue has been found.
Spring pressure not high enough.
There was 165lb on the seat which is quite normal.
Those Yella Terra Pro street rockers are heavy and require more spring pressure.
This was raised but not sure by how much and power has shot up to 350rwkw now so we are on the right track. Power should be around 380rwkw once it's all working good.
Once Valve Train is sorted then we will see from there with the heads.
More than likely we will try a thicker head gasket to get some more timing in too.
Compression test was done.
All good.
No dead cylinders here.
One issue has been found.
Spring pressure not high enough.
There was 165lb on the seat which is quite normal.
Those Yella Terra Pro street rockers are heavy and require more spring pressure.
This was raised but not sure by how much and power has shot up to 350rwkw now so we are on the right track. Power should be around 380rwkw once it's all working good.
Once Valve Train is sorted then we will see from there with the heads.
More than likely we will try a thicker head gasket to get some more timing in too.