I LOST 20ftlbs. And 5 hp!
Thanks again. I would also like to give props to Mike at New Era Performance. Once your initial tune is done they only charge you 150.00 for a retune. He was shocked at the drop in power (evethough it had nothing to do with his tune,it was just parts being swapped) he only charged me 1 hr shop rate for the second tune. These guys are top notch and have many custom products all fabricated up in house for the whole Ls line up.
Looking at your dyno graph again the old pulls were much smoother, while the new graph is rougher. How many miles are on the valve springs and when's the last time you did maintenance stuff like fuel filter, etc.
Meh, a gain of 5ft lbs and 6HP by going to longtubes isn't enough to justify the cost of the longtubes as is. Maybe with a different cam, heads or intake the results might be better.
To me the graph with the LTs is pretty rough compared to the Macs. Why.... I don't know.
If I put the LTs back on I will cut the back of the y merge off where it reduces down to 2.75" to join up with the cat back which opens back up to 3" and make it all 3". The Macs y was 2.75" all the way back.
If you already have the mac's yeah with a bolt on car it may not be worth it to upgrade to 1 7/8 long tubes.but if you don'thave headers at all it's worth putting the 1 7/8 long tubes on just in case you all more aggressive heads and cams setup.
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Track times can be manipulated by weight reduction, gears, converters, line locks...the list goes on. Even the weather that day can effect it. Hardly any of that would show on a dyno. You are saying a loss on the dyno of 20 ft lbs (and what appears to be all over a loss) and no gain in hp can equal a faster time at the track...then i do not believe you.
Dynos have weather stations and correction factors for those discrepancies. Drag strips you ran what you ran.
Dynos have weather stations and correction factors for those discrepancies. Drag strips you ran what you ran.
You can also measure DA and correct all the runs for it as it changes.
Personally I've seen much larger swings in dyno numbers (especially automatics) than I have properly measured and corrected track times.
If you would have said you slowed down at every increment at the drag strip after the changes, that would have been surprising.
Showing a negligible difference on a dyno, months apart with different dyno settings is not mind blowing. Don't hang your hat on dyno numbers.
Showing a negligible difference on a dyno, months apart with different dyno settings is not mind blowing. Don't hang your hat on dyno numbers.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Only a gain above 5700 and honestly a paltry gain at that for long tubes seems hardly worth it to me. Maybe on a larger cam it would be different. Too many variables to even say yes or no to.
If someone bought 2 separate cams and had only that gain, yall would be sacrificing the second cam designer.
If someone bought 2 separate cams and had only that gain, yall would be sacrificing the second cam designer.
Only a gain above 5700 and honestly a paltry gain at that for long tubes seems hardly worth it to me. Maybe on a larger cam it would be different. Too many variables to even say yes or no to.
If someone bought 2 separate cams and had only that gain, yall would be sacrificing the second cam designer.
If someone bought 2 separate cams and had only that gain, yall would be sacrificing the second cam designer.
That has been answered before. Because not everyone has access to a track. Or are set up to drive on a track. In getting a new cam or headers youll need a tune. Normally that ends in a dyno. And for the most part it doesnt go beyond that. As far as the new street outlaws fad, there is no time on that just 1 vs other which is normally a driver race or all in the suspension setup.
Before and after times would be great as any point of information is good, but not always possible.
Plus how else can you bench race against the mustang guys without numbers?
Before and after times would be great as any point of information is good, but not always possible.
Plus how else can you bench race against the mustang guys without numbers?
Track mph with DA correction is far more accurate than comparing dynos. OP did a great job with his back to back to back, but it's widely know that you throw ET out the window at the track when comparing mods, but mph doesn't lie except for very specific situations like high hp and no traction.
Depends on how the car is used. Midrange torque is great for a street car, high end HP is better for a drag car.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I started thinking about this thread on my way home from work and I got home, walked in the door and punched my cat. Now I have a large vet bill to pay. Thanks OP. 