Aluminum Intake Manifold

M1ck3y · May 16

Would an aluminum intake manifold heat soak and effect power?

I ask because I’m considering BTR’s truck intake manifold. It loses maybe 40 ft lbs in the mid range but gains 60 plus horsepower/torque up top out to 7000.

CamGTP · May 16

Anything metal will heatsoak, no way around that. Only way to cool the intake charge is with a intercooler or heat exchanger of some sort.

Ask yourself this though, how often are you riding that 5,000-7,000rpm rev range? Probably not very often, losing that 40ft/lbs is a lot in that 2,500-5,000rpm section, to me that's not worth it. Adding a camshaft to the engine that suits the proper torque converter would be a better idea to me.

M1ck3y · May 17

2 hours ago, CamGTP said:

Anything metal will heatsoak, no way around that. Only way to cool the intake charge is with a intercooler or heat exchanger of some sort.

Ask yourself this though, how often are you riding that 5,000-7,000rpm rev range? Probably not very often, losing that 40ft/lbs is a lot in that 2,500-5,000rpm section, to me that's not worth it. Adding a camshaft to the engine that suits the proper torque converter would be a better idea to me.

I am adding a btr 220 cam. And your right I spend very little time at peak rpm. But I’m looking for full throttle power.

CamGTP · May 17

I don't that that adding a camshaft is going to give up 40-60hp throughout the rev range if not more. The stock truck intakes are really good for torque.

M1ck3y · May 17

6 hours ago, CamGTP said:

I don't that that adding a camshaft is going to give up 40-60hp throughout the rev range if not more. The stock truck intakes are really good for torque.

No, the camshaft doesn’t give up much, if any in the mid range. But the Btr truck intake manifold does.

Heres an example on an L8T. The third intake manifold in the graph is a short runner design and it gives up even more in the mid range.

M1ck3y · May 17

The cam does give up a bit below 2500…

SeekAndDestroy · May 17

12 hours ago, M1ck3y said:

The cam does give up a bit below 2500…

I have that cam in my 2018. BTR makes quality stuff. With headers it added +100 hp and +80 torque. I don't notice the tiny loss of torque below 2500. After 2500 it takes off like a rocket. The idle chop sounds so good. Been trouble free for 30k km

M1ck3y · May 18

1 hour ago, SeekAndDestroy said:

I have that cam in my 2018. BTR makes quality stuff. With headers it added +100 hp and +80 torque. I don't notice the tiny loss of torque below 2500. After 2500 it takes off like a rocket. The idle chop sounds so good. Been trouble free for 30k km

Was that with e85 too? What Catback are you running? I need to change mine from Corsa Sport; its just too loud with headers.

Edited May 18 by M1ck3y

SeekAndDestroy · May 18

2 hours ago, M1ck3y said:

Was that with e85 too? What Catback are you running? I need to change mine from Corsa Sport; its just too loud with headers.

No, tuned for 91. E85 is hard to find here, only one station in the whole city has it.

I have full custom exhaust. 1-3/4” Kooks headers, kooks y-pipe with high flow cats then it duals into 2.5” pipes with Dynomax mufflers. Loud AF. I’ve heard that the Magnaflow 12909 muffles headers good.

This is the dyno sheet. They said it was a 4th gear pull, and it would have 5-7% more power if it was done in 6th.

M1ck3y · May 18

6 hours ago, SeekAndDestroy said:

No, tuned for 91. E85 is hard to find here, only one station in the whole city has it.

I have full custom exhaust. 1-3/4” Kooks headers, kooks y-pipe with high flow cats then it duals into 2.5” pipes with Dynomax mufflers. Loud AF. I’ve heard that the Magnaflow 12909 muffles headers good.

This is the dyno sheet. They said it was a 4th gear pull, and it would have 5-7% more power if it was done in 6th.

yesh I was thinking I’d try magnaflow out. They have a single exit 4” with two mufflers.

Nice numbers. I’m getting my work done at the same place!

SeekAndDestroy · May 18

3 hours ago, M1ck3y said:

yesh I was thinking I’d try magnaflow out. They have a single exit 4” with two mufflers.

Nice numbers. I’m getting my work done at the same place!

They are good. If you can afford it, get an aftermarket converter with a slightly higher stall than stock. The only issue I have is when I’m coming to a stop the cam will push through the brakes. Not every time, but it’s pretty sketchy on a slippery snow day

M1ck3y · May 18

1 hour ago, SeekAndDestroy said:

They are good. If you can afford it, get an aftermarket converter with a slightly higher stall than stock. The only issue I have is when I’m coming to a stop the cam will push through the brakes. Not every time, but it’s pretty sketchy on a slippery snow day

Yikes, I didn't think this cam was that aggressive. Looks like I'll have to be quick on shifting to neutral. Converter isn't in the cards.

Do you know why Davenport didnt dyno in 6th? my under standing is the driveshaft is good until 125ish, was it your tires?

Edited May 18 by M1ck3y

M1ck3y · May 18

On 5/16/2025 at 3:23 PM, CamGTP said:

Anything metal will heatsoak, no way around that. Only way to cool the intake charge is with a intercooler or heat exchanger of some sort.

Ask yourself this though, how often are you riding that 5,000-7,000rpm rev range? Probably not very often, losing that 40ft/lbs is a lot in that 2,500-5,000rpm section, to me that's not worth it. Adding a camshaft to the engine that suits the proper torque converter would be a better idea to me.

I've read that the air is moving so fast through the intake that it doesn't really have time to absorb any heat before it enters the cylinder. Is that true? I'm also wondering if you have any real world experience with an aluminum intake; did you notice higher iat's over a plastic one?

Edited May 18 by M1ck3y

SeekAndDestroy · May 18

2 hours ago, M1ck3y said:

Yikes, I didn't think this cam was that aggressive. Looks like I'll have to be quick on shifting to neutral. Converter isn't in the cards.

Do you know why Davenport didnt dyno in 6th? my under standing is the driveshaft is good until 125ish, was it your tires?

It’s not very often, maybe once a month if the tranny downshifts funny. It’ll do one lurch forward. I just mash the brakes harder, lol.

In 6th gear at 6100 RPM I’ll probably be going 180-200 Km/hr. The driveshaft might handle that RPM but the tires are not rated. Just safer for them to dyno it in 4th and do the math after.

M1ck3y · May 18

31 minutes ago, SeekAndDestroy said:

It’s not very often, maybe once a month if the tranny downshifts funny. It’ll do one lurch forward. I just mash the brakes harder, lol.

In 6th gear at 6100 RPM I’ll probably be going 180-200 Km/hr. The driveshaft might handle that RPM but the tires are not rated. Just safer for them to dyno it in 4th and do the math after.

makes sense. I just used a calculator to figure out the rpm vs speed. Looks like I’ll have to do a 3rd gear run with my heavy LT tires…