I didn't say timing because I don't want everyone going out and changing their tune to mine and breaking stuff. I am not completely satisfyed with it even though it makes good power because of how unsafe it is.. It is 30 degrees of timing. And LOL at saying cutouts don't make a difference.. I'll throw it back on the dyno and show you the difference..

 

 

You kept the timing secret to protect us? Very commendable but why not just say you don't recommend tuning like this? We're all here to learn from each other. But that requires accurate info.

Please do, and this time get corrected numbers for us. I didn't say they don't make a difference, I said I doubt they add much more than a good free flowing exhaust. I was also speaking of your particular type of build. A mild bolt-on set up.


Here. Mr. Joe_G has the knowledge, experience, and more importantly, THE DYNO AND TRACK RESULTS to prove his claims. This was on his bolt on build similar to yours. Little-to-no gains with cutouts open.



Even on his cammed build he only got a 6rwhp/rwtq gain. Do you believe cutouts made more power on your bolt on stock cammed car than on his cammed car?




Honestly, if you're not happy with the tune, didn't get accurate dyno numbers, and having problems with the clutch, I'm assuming they installed it(?). First and foremost I'd get the car sorted out.

 

30* of timing, larger injectors and E85 and 430 is very attainable in a bolt-on LS2. There was a bolt-on E85/Torco LS3 laying down 450rwhp a few years ago and trapping 123-124mph. He's the torco guy on here, I believe his s/n is jbsblownc5. I wouldn't run 30* of timing on 93. Usually stock 243 heads don't like timing over 22/23* and anything higher and they lose power. AFRs and TFS heads likes timing around 27-28* and makes max power there.

 

The OP is driving a ticking timebomb. 30* timing, 7k rpms, stock valve springs, stock oil pump, stock ls2 intake manifold. Honestly, there is nothing impressive with this setup other that WTF are doing and where are you getting your information from saying this is ok. And what was the point of installing ARP rod bolts to spin to 7200rpms with all else being stock.

 

I'd like to see the OP's dyno graph to see why he's revving it to 7k rpm. I seriously doubt the stock LS2 cam makes much power past 6500 rpm. I know my old LS2 GTO with the stock cam was out of breath near redline.

 

Yeah the dyno graph and timeslips are missing..

1/4 E/T: 12.3
1/4 mph: 110
60' : 2.0

From Specialsause:


This pass was on a set of bridgestone potenza's with 18000 miles on them that have been sitting up for 10 months while my car didn't have an engine.. This resulted in immediate loss of traction after i left the prepped section of track and wheel hopping/spinning literally the entire way down the track...

I ran a 13.22 at 118mph in my stock 2008 Z06 at 5000ft above sea level spinning the stock worn out tires; on and off the throttle all the way through the prepped section (really) of the track in first gear and well into second gear. You wouldnt have a 12.3 or a 2.0 60Ft time with tires spinning and a bad clutch master cyl.
somehow 2+2 is adding up to6

 

The OP took his car to a dyno in Slidell, LA on Nov 1, here's the weather data for that day:

http://www.wunderground.com/history/...name=Louisiana

As you can see, the temperature was 60°F (15.5°C) at 9:30 AM where the dew point was 42°F and the barometric pressure was 1025.5 hPa. Using the SAE correction (revised Aug 2004) formula of cf = 1.176[(990/Pd)*√(Tc+273/298)] -.176 where Pd is the pressure of dry air in mb (1 hPa=1 mb) and Tc is the temperature in °C, we have:
cf = 1.176[(990/1016.4)*√((15.5+273)/298)] -.176 = .951

Note: Pd=P-Pv where P is the atmospheric pressure and Pv is the water vapor pressure. Pv=C0*10^[(C1*Tdp)/(C2+Tdp)] where Tdp is the dew point temperature in °C, C0 is 6.1078, C1 is 7.5, and C2 is 237.3. The above can be seen at:
http://wahiduddin.net/calc/density_altitude.htm
Equations 6, 7a, and 8a are germane.

430*.951=408.98 RWHP, but we're not finished...the SAE correction also provides a method to capture the affect ambient conditons have on the HP going to engine friction as detailed here:
http://wahiduddin.net/calc/cf.htm
Scroll about halfway down to SAE J1349 Update. Using 85% engine mechanical efficiency (not to be confused with drivetrain efficiency), we have 430*.15*(1-.951)=3.15 HP

408.98-3.15= 405.83 RWHP

A lot of posts have stated he should be around 390-400 RWHP and if you allow 5 HP for the lightweight flywheel he didn't mention in his first post, you guys have just spent 8 pages arguing over 0-10 RWHP which is within the error of a chassis dyno.

It has been entertaining though.

 

Wrong again, SAE corrects to 77°F/25°C so 60°F would contribute significantly to a correction factor...see above. As you said, the total correction factor would depend on the pressure which makes your comment of "no correction factor" even sillier since you had no clue what the pressure was.

 

This debate is still going???

 

That's the funny thing...it sounds like a debate but it isn't. The OP says his car made X HP uncorrected and the corrected numbers would be lower while everybody else says his corrected numbers would be lower which means they've spent the last 8 pages saying the same exact thing. A debate requires two distinct and opposite positions to be represented/supported...

There are people who disagree with his 7000 RPM redline but we've had that discussion before and the result was the car is faster in the 1/4 mile. It does carry added risk but if he wants to wind the spring that tight, it's his engine and he can do what he wants with it.

 

What intake/exhaust LS2 has been quicker in the 1/4 shifting at 7k?

Me, Dicky, LS1LT1 and Dennis have the quickest bolton LS2s, and I don't believe any of us shift near that.

 

There is a special case in which the op would have a Cam, a very mild cam
with with little overlap and almost unnoticeable lope. 430 rw would sit
well with with most members SAE or uncorrected if that was the case. The
7000 RPM would be attainable if the Springs were in there. The Cams most
of us use peak at 6400 RPM but can go over 7000 if you care to. I 'm not
saying the OP has a Cam but many posts back I heard something about
a Engine change.

 

Post your (or any of the guys above) dyno sheet going out to 7000 RPM.

 

im at work now but ill try to get it this afternoon sometime for you, if i remember right the hp drops off hard about 6500-6600.

 

Well YOU stated that the car in question would be quicker at 7k shiftpoints, and I'm wondering what your basis is as the 4 quickest shift below that.

My car shifts at 6350 because the power starts to drop off quickly after that. It's just downhill to 7k, which I did run it up to on the dyno several times after different changes.

I don't have any dyno sheets of my setup...never got any sent to me or printed because it didn't really matter to me. It made ~397/405 or something like that SAE corrected through a 3200 stall.

 

Mine is done at 6500 rpm and I have a FAST intake.

http://forums.corvetteforum.com/c6-t...aust-dyno.html

 

More importantly you have a Cam, lol.

 

Well I don't know about that, but if that is how it went down then they likely weren't going faster for too many passes LOL.
I do believe I could see slightly more ET reduction with a couple more hundred RPM tacked on to my shifts (last time I looked at my dyno sheet and logs from some passes it showed that at least). But LSx history has taught us that it will be a short lived gain (if at all) in almost every case as those springs give up awfully quick when pushed too far and losing a valve/destroying my bone stock valvetrain simply isn't worth it to me.
Apparently it is worth it to the OP.
I believe that Tom ('HOXXOH') down in AZ goes a little far with his stock LS3's redline as well and I hope he too doesn't pay the ultimate price for it (though it is an LS3 and not an LS2 of course).




Absolutely.
But for one to still argue, debate and even attempt to discredit the proven information provided by those who know that risk and who even offer advice/warnings on the topic can make one appear, well, just a little obtuse or ignorant as well, no?
But then again, what does that make those of us who are actually still debating with someone such as that? LOL





Good point.

 

A factory LS2 intake doesn't even flow enough air to make power at 7k rpms.

The OP mentioned his engine has been out of the car, perhaps it's blown before and he hasn't learned his lesson.