Lesson learned. Skip the intake

[christianchevell]

Some have been into doing the tunnel ram high rise intake and that's nice for racing and posting bigger numbers with high revs but they are not as street friendly in the lower part of the band for power. Also metal is inherent to heat soak more than phenolic resin made intakes. A few I have seen have cut the firewall for clearance to use the high rise and a couple who did not I believe its about the only real great gainer being its long runners compared to the Fast or thinking of the cost for ls7 small bore heads to go with the Air force intake. What the others say about the rod mod/ stock porting and stuff over time is mostly positive it is not claimed to gain any great advantage and is much more cost effective than dumping a bunch into a intake and maybe a 102mm to go with it.

[JakeW1990]

Originally Posted by Soybeanrice

We'll see what happens. Sounds like a doable goal.

I do have a noobie question in terms of accelerating. What moves the car or where should i be focusing my shifts? Should my shifts be focused on the torque or horsepower band?

I shift at stock limit of 6500 with my BTR Stage 4. Stage 4 is 68-7000 rpm limit. I haven't looked up the Stage 3 specs, but I imagine you're outside the most efficient operating parameters shifting it at 7k by 2-300 rpms. I'd say shoot for 6,700 and bang another gear.

Torque gets you rolling and horsepower maintains it. 4K seems to be where these cars are torque monsters with redline falling of 50ft lbs or so. Too low of a shiftpoint though and the HP won't be enough to keep that needle going. :-p

[xc_SS/RS]

I know the exhaust is the main restriction on our cars, but could the lack of gains maybe be from the intake manifold? Could the longer intake runner length be hurting the power gain instead of helping, or is this just the result once you've done headers and cam without changing the intake before those?

[Soybeanrice]

Originally Posted by xc_SS/RS

I know the exhaust is the main restriction on our cars, but could the lack of gains maybe be from the intake manifold? Could the longer intake runner length be hurting the power gain instead of helping, or is this just the result once you've done headers and cam without changing the intake before those?

Good questions that I wish I could answer. I cant imagine the longer intake runner length hurting the bottom end, but it could very well be the culprit. I'm going to bring the stock air box to throw on and isolate the manifold. Then we're gonna try taking off the cats and running with just headers to see what we get.

My hypothesis is that the headers alone will not make a difference. I believe that the 2.5inch stock exhaust is plenty for NA. Its just the ports on the head. Once again, my hypothesis.

The only real benefit of going aftermarket exhaust is dropping weight.

As for the intake, It would be really interesting to put on the stock air box and have the same curve but with less power all around... It would mean that the ADM intake was giving power while the manifold was dropping it for the top end.

All to be tested hopefully... Or I could get lazy. Most likely the latter.

[xc_SS/RS]

Originally Posted by Soybeanrice

Good questions that I wish I could answer. I cant imagine the longer intake runner length hurting the bottom end, but it could very well be the culprit. I'm going to bring the stock air box to throw on and isolate the manifold. Then we're gonna try taking off the cats and running with just headers to see what we get.

My hypothesis is that the headers alone will not make a difference. I believe that the 2.5inch stock exhaust is plenty for NA. Its just the ports on the head. Once again, my hypothesis.

The only real benefit of going aftermarket exhaust is dropping weight.

As for the intake, It would be really interesting to put on the stock air box and have the same curve but with less power all around... It would mean that the ADM intake was giving power while the manifold was dropping it for the top end.

All to be tested hopefully... Or I could get lazy. Most likely the latter.

Yeah the longer runners should benefit the low end, but your gains were up top which could be the ADM intake. I'm curious if the rod mod intake isn't ideal with a cam/this cam? It could be a bunch of different things/not ideal parts combo as well.

[DOC52]

Could it possibly be the tune/tuner?

[camaro500]

The CAI, PTB and Manifold mod is an excellent combo and makes power no matter what NA setup you are running. I don't mean to disrespect you or the thread you started but what's the point? Countless track times and dyno runs from other members (myself included) and shops have proven your conclusion (based on your dyno run) WRONG.
You did not waste your money unless you are going with a turbo or supercharger setup in the near future. Enjoy your beautiful setup!

[JakeW1990]

Originally Posted by Soybeanrice

Good questions that I wish I could answer. I cant imagine the longer intake runner length hurting the bottom end, but it could very well be the culprit. I'm going to bring the stock air box to throw on and isolate the manifold. Then we're gonna try taking off the cats and running with just headers to see what we get.

My hypothesis is that the headers alone will not make a difference. I believe that the 2.5inch stock exhaust is plenty for NA. Its just the ports on the head. Once again, my hypothesis.

The only real benefit of going aftermarket exhaust is dropping weight.

As for the intake, It would be really interesting to put on the stock air box and have the same curve but with less power all around... It would mean that the ADM intake was giving power while the manifold was dropping it for the top end.

All to be tested hopefully... Or I could get lazy. Most likely the latter.

LS3 intake is one of the best flowing intakes there is. Most people don't do an intake on these cars unless you've got money laying around that you don't know what to do with or have already done everything else.

2.5" exhaust doesn't reference the entire exhaust. You run into issues with the stock diameter header openings bottle-necking exhaust gas in addition to catalytic converters restricting flow. My guess is they are probably 1.5" diameter header openings. Most people buy 1 7/8" headers. Even those headers are only good for up to about 700hp and then they will bottle-neck the exhaust gasses trying to leave the engine after that. Does that mean you can't make more than 700hp? No, but you won't see gains you typically would by properly referencing exhaust flow to match header diameters.

1 7/8" headers + tune nets around 50hp gains. They DEFINITELY make a huge impact to the system (that sound though! <3) and one of the best $ to $ mods.

Headers 600-900$ - 50hp
Intake 800-1000$ - 10hp

[Soybeanrice]

Originally Posted by DOC52

Could it possibly be the tune/tuner?

My tuner is Geoff at Next Level Performance... Found him through ls1tech.

Hes been in the game a while so i would hope not. On my previous tune, I know i was running rich because i pulled the spark plugs and they were wet.

I wish tuning was easy to get in to, but it seems like PDR, an exclusive art

[Soybeanrice]

Originally Posted by camaro500

The CAI, PTB and Manifold mod is an excellent combo and makes power no matter what NA setup you are running. I don't mean to disrespect you or the thread you started but what's the point? Countless track times and dyno runs from other members (myself included) and shops have proven your conclusion (based on your dyno run) WRONG.
You did not waste your money unless you are going with a turbo or supercharger setup in the near future. Enjoy your beautiful setup!

If youre going to bring dyno charts into this, I have a dyno chart on the first page to look at lmao. I guess that chart is "WRONG". I mean, the chart is right. I did make a gain, but was it as advertised? I'm giving people some information on what to expect too. I know making more power gets harder and harder too

The point of the thread is that I spent 900 bucks on the intake (up to the heads) instead of 1200 on getting the heads done. This is me doing the labor myself. I know all the intake parts are a cakewalk to install compared to the heads, but some people like to do everything themselves and could possibly use this information.

I feel a little burned that my combination of parts didnt meet my expectations. Hopefully this could deter someone away from the same mistake. Like someone previously mentioned, it could be that my intake setup just doesnt work with my cam combo.

[Soybeanrice]

Originally Posted by JakeW1990

LS3 intake is one of the best flowing intakes there is. Most people don't do an intake on these cars unless you've got money laying around that you don't know what to do with or have already done everything else.

2.5" exhaust doesn't reference the entire exhaust. You run into issues with the stock diameter header openings bottle-necking exhaust gas in addition to catalytic converters restricting flow. My guess is they are probably 1.5" diameter header openings. Most people buy 1 7/8" headers. Even those headers are only good for up to about 700hp and then they will bottle-neck the exhaust gasses trying to leave the engine after that. Does that mean you can't make more than 700hp? No, but you won't see gains you typically would by properly referencing exhaust flow to match header diameters.

1 7/8" headers + tune nets around 50hp gains. They DEFINITELY make a huge impact to the system (that sound though! <3) and one of the best $ to $ mods.

Headers 600-900$ - 50hp
Intake 800-1000$ - 10hp

I already have 1 7/8 heads. They go into a 3 inch collector and the exhaust goes from 3 inch to 2.5 at the cats. cat back is the NPP stock

The rod modded intake was 250. It still uses the stock intake.. it just technically increases the intake running length with the rods installed

[Pro Stock John]

Originally Posted by Soybeanrice

We'll see what happens. Sounds like a doable goal.

I do have a noobie question in terms of accelerating. What moves the car or where should i be focusing my shifts? Should my shifts be focused on the torque or horsepower band?

You'll run best shift after peak HP.

If you peak at 6500, I'd shift between 6700-7100. Reason being it's not only about peak HP it's also about RPM drop on the shifts, and making sure the RPMs don't drop to around peak torque (cuz the tuner will have a bunch of timing out of the tune at peak torque otherwise the cars will knock).

Geoff Skorupa is very knowledgeable.