How much hp is a slightly ported 1pc intake good for

[chromguy]

N/A engines it makes a big difference, assuming a turbo vehicle is running a turbo of proper size altitude effects them very little.

14 psi in the intake is 14 psi in the intake regardless if you are in Death Valley or climbing Mount Washington.

Have you ever raced a turbo car at both sea level and altitude?

Gary is correct, let me explain, my day job is a chromatography scientist and I work with pressures from one billionth of an atmosphere to 20,000 lbs/square inch (over 1000 atmospheres).
There are two different ways gauges report pressure, wrt normal consumer goods. One is PSIG, the “G” stands for gauge, this reports pressure relative to atmospheric. Your boost gauge on your dash is PSIG and as such will vary if at sea level vs the mountain top, as less air pressure on the gauge mechanism. Another example is your tire gauge or those on your acetylene tank. The other type is PSIA, the “A” stand for absolute , this is how our map sensor works and a barometer on your weather station..


Normal atmospheric pressure at sea level is 14.69psi.At 5,000ft the PSIA is 12.23. This is why the difference is significant with a NA motor.
Since our MAP measures PSIA and the turbo will pressurize to 14PSI(Boost setpoint) +14.69PSIA(Atmospheric pressure constant) =28.69PSIA. Please note the 14.69 is a constant and does not change with elevation.


This is why there is little difference with elevation with a turbo motor using a MAP measuring PSIA such as ours.
I hope this helps

[glhs875]

Yup, 1-2% increase in shaft speed per 1000 foot increase in altitude to maintain set power level.

Any other questions?

There is you answer,you have to make changes to cover the loss in power that is made!
Increase in backpressure to increase shaft speed is one factor that comes into play. There are others as well. This topic could use it own thread!

[cordes]

Indeed... I'm on a tablet right. Now. So moving all these posts to a separate thread. Will have to wait.

Digression aside, I would ask for everyone to be polite when posting. I don't care if I agree or disagree with folks on here when it comes to science. I think one thing we can all agree on is that a little politeness goes a long way and it's been lacking in this thread to a large extent. We're all in this together and there aren't enough of us around to be jerks to one another. IMO most every other car clique does a good enough job of crapping on us any chance they get that we don't need to do the same to each other.

[The Pope]

fact is air plus fuel is going to equal HP, higher RPM equals more HP with the same air flow. The 1 piece restricts RPM and air flow. Slamming 30+ PSI to one you are going to get some air through it. Put that same boost to a BMF intake and you are in a whole other solar system with supporting mods. I did do some intake testing, hooked to a 185 CFM head over the stock 135 CFM head.

Stock head and 1 piece, 122 CFM
ported head and 1 piece, 135 CFM
Ported head and 2 piece, 145 CFM
Ported head and ported 2 piece, 166 CFM
Ported head and ported lower piece and plenum, 175

Clearly a ported head is getting killed by the restricted intake. Then you have operation. The Plenum shortens runners and has a lot more volume. So you gain RPM range and flow, so you get power from RPM range and the flow. It is just foolish to spend 1200 on a head, 1500 on a big ball bearing turbo, then say 500 is too much for an intake to use it and plop on a $10 1 piece lol. Don't listen to anyone, actually flow test your head with and without the intake. The 2.2 isn't a Cummins, building for low RPM low HP and massive torque with massive boost makes no sense. Looks don't always mean anything either. My ported stock exhaust out performed a 4-1 tube header hooked to the head, It was pretty sweet looking but didn't flow. Cost me $50 a test, "just do it"

[The Pope]

For clarity, as some may be confused by my first sentence after I read it. Lets look at some rough math based off of my flow numbers. Cams change things too but we'll leave that out for now.

122 CFM, cubic feet per minute, 4,500/4 (4 stroke) RPM revolutions per minute. So 4500 * 122 for 122 at 1125. That is 137,250 at 4500 RPM
122 CFM 7,000 RPM. So 122 at 1750 is 213,500

So at the same intake flow, but working differently for high RPM you move 213,500 CFM at 7,000 vs 137,250 CFM at 4,500. So with a plenum intake and matching cam you make a lot more power.

175 CFM 7,000 RPM. So 175 at 1750 is 306,250 CFM

So pour boost to 137,250 CFM and then pour boost to 306,250 CFM...... The combination of RPM and CFM working together is a beautiful thing, running more boost to compensate is dumb. As the same boost just nets a lot more HP with flow. This is a bit over simplified, but more flow means a bigger turbo, bigger IC, bigger cam and it still spools. At some point your turbo holds you back and more flow pushes a bigger turbo....

[mopar-tech]

Clearly a ported head is getting killed by the restricted intake.

Define "killed"

A -> B Dragstrip testing doesn't support your conclusion. Flow benches are a nice tools but they don't always tell the whole story.

The Reliant went from an 1 piece intake with 52" mm TB with 2.5" intercooler plumbing to a 2-piece with very heavy mods, 58 mm TB and 3" mandrel bent intercooler plumbing with no other changes. Head on the car was well ported, turbo generous, etc.

Conventional wisdom indicated I should have seen a major change in performance, I got less than 2 tenths. And that was with some weight removed from the car too. I'll not turn down the change in the car, every little bit helps in the march towards lower ET.

Is the 1-piece better than a 2-piece? Nope. 2-piece has a slight advantage.

Is the 1-piece as bad as some people say? Not from what I have seen.

Choose your performance goal and pick your parts.

FYI- There are great discussions about intake manifolds on the Ram/Dakota forums. There is a big flow disparity between the good intakes and heads on the 5.2 and 5.9 engines.

FYI x2- The performance and power ratings between 1987 and 1988 Daytona TII package didn't change with changing of the intake manifold which *may* indicate the change in intakes is a wash. If the 2-piece is so superior why was there not a major de-rating in power and performance when Chrysler swapped to the 1-piece?

[83scamp]

I guess the real take-away from all this is:

The 1 piece isn't the horrible restriction once thought on a street motor. If you're building a drag motor and want to run 7K rpm, it's obviously not a good choice. Most folks don't run that hard on the street. At least I don't, even on my N/A motor...

It appears the 1 piece is a viable solution up to about 250 hp at least. But as with any build, it's the combination of parts working together that give you the biggest bang for the buck...

I want to thank again everyone who has contributed to this thread. It has actually come at a very good time for me, because I am currently collecting parts for a motor build for my Scamp. I will be putting it together over the winter to hopefully have it running in the spring. If it all goes as planned, the Scamp should be sporting about 3X the hp next year...

[tryingbe]

Can we all agree on, BMF > stock 2 piece > *slightly (NOT cut open and re-weld) ported 1 piece > stock 1 piece?

Can 1 piece make power? Sure, would all the other intake manifolds make more power? Absolutely. How much more power? That varies a lot.

[sdac guy]

After MANY complaints about some posts in this thread, which were either not contributing to the subject matter, or inflammatory, or both, the mods agreed this thread needed to be cleaned up.

I have just finished that process by deleting all the posts I found in this thread that fell into the above category. I deleted all offensive posts and their respective replies, so there is no relationship overlap, or partiality towards users being shown.

We will keep an eye on this thread for further disruptions and eliminate them as required.

This is an interesting thread, lots of facts, lots of opinions. Who would have imagined such a simple question would lead to such a thorough discussion?

Enjoy!


Barry

[Shadow]

Define "killed"

A -> B Dragstrip testing doesn't support your conclusion. Flow benches are a nice tools but they don't always tell the whole story.

The Reliant went from an 1 piece intake with 52" mm TB with 2.5" intercooler plumbing to a 2-piece with very heavy mods, 58 mm TB and 3" mandrel bent intercooler plumbing with no other changes. Head on the car was well ported, turbo generous, etc.

Conventional wisdom indicated I should have seen a major change in performance, I got less than 2 tenths. And that was with some weight removed from the car too. I'll not turn down the change in the car, every little bit helps in the march towards lower ET.

I would be curious to know what turbo you were running during this swap? Also, what MPH gain that came along with the lower ET?

I guess the real take-away from all this is:

The 1 piece isn't the horrible restriction once thought on a street motor. If you're building a drag motor and want to run 7K rpm, it's obviously not a good choice. Most folks don't run that hard on the street. At least I don't, even on my N/A motor...

It appears the 1 piece is a viable solution up to about 250 hp at least. But as with any build, it's the combination of parts working together that give you the biggest bang for the buck...

I want to thank again everyone who has contributed to this thread. It has actually come at a very good time for me, because I am currently collecting parts for a motor build for my Scamp. I will be putting it together over the winter to hopefully have it running in the spring. If it all goes as planned, the Scamp should be sporting about 3X the hp next year...

You seem to be gleaning the Right info from this thread, as I would tend to agree with what your concluding. Although you Could stretch the 1 piece a little further than 250HP

Something to keep in mind; Most are going to go off of their Own experience in these matters and many have different experiences, specially when it comes to boosted applications. (boost can mask many things)

Back in the day we would swap 2 piece intakes on to 20psi (stock TII Garrett turbo) 2.2 applications and gain 2-300rpm peak power, which I thought was a significant return for a simple change in stock intakes. So the 2 piece became part of the recipe for us very Early along the build trail. Being RPM conscious, we mostly stuck with the 2.2 as a build platform as well.

When the Charger was running the 57 trim stage 3 turbo at 33lbs boost with fully ported 2 piece and 52mm TB, decent ported +1mm G-head, 2 stock I/C's y-piped with 2 1/2" hardpipes and stock 88 roller turbo cam. I built a custom 1 piece large plenum short runner manifold with 58mm TB and swapped it on with no other change.

Now, I had Just solved my spark blow-out problem with Aurora ignition and .028 gap, everything was working tickity Boo. I still remember how tinny that manifold sounded, like the valves were opening and closing right in front of me. First time I put it down it was lean, so I started adding fuel. (just rudimentary at the time with AFPR) Ended up adding 5-6psi fuel pressure to get the AFR's back in line @ 33lbs boost and was instantly blowing out the spark again, so I started closing the gap on the plugs. I believe I closed the gap to .018 - .020" to stop the spark blow-out and the next trip to the track the Charger picked up 3-4mph.

That was a Very Significant change IMM and I took it as a 30-40WHP gain with no other change. (also ended up going with a Stronger aurora ignition after that lol)

[Shadow]

Can we all agree on, BMF > stock 2 piece > *slightly (NOT cut open and re-weld) ported 1 piece > stock 1 piece?

Can 1 piece make power? Sure, would all the other intake manifolds make more power? Absolutely. How much more power? That varies a lot.

I think that sums it up quite well

[83scamp]

I would be curious to know what turbo you were running during this swap? Also, what MPH gain that came along with the lower ET?



You seem to be gleaning the Right info from this thread, as I would tend to agree with what your concluding. Although you Could stretch the 1 piece a little further than 250HP

Something to keep in mind; Most are going to go off of their Own experience in these matters and many have different experiences, specially when it comes to boosted applications. (boost can mask many things)

Back in the day we would swap 2 piece intakes on to 20psi (stock TII Garrett turbo) 2.2 applications and gain 2-300rpm peak power, which I thought was a significant return for a simple change in stock intakes. So the 2 piece became part of the recipe for us very Early along the build trail. Being RPM conscious, we mostly stuck with the 2.2 as a build platform as well.

When the Charger was running the 57 trim stage 3 turbo at 33lbs boost with fully ported 2 piece and 52mm TB, decent ported +1mm G-head, 2 stock I/C's y-piped with 2 1/2" hardpipes and stock 88 roller turbo cam. I built a custom 1 piece large plenum short runner manifold with 58mm TB and swapped it on with no other change.

Now, I had Just solved my spark blow-out problem with Aurora ignition and .028 gap, everything was working tickity Boo. I still remember how tinny that manifold sounded, like the valves were opening and closing right in front of me. First time I put it down it was lean, so I started adding fuel. (just rudimentary at the time with AFPR) Ended up adding 5-6psi fuel pressure to get the AFR's back in line @ 33lbs boost and was instantly blowing out the spark again, so I started closing the gap on the plugs. I believe I closed the gap to .018 - .020" to stop the spark blow-out and the next trip to the track the Charger picked up 3-4mph.

That was a Very Significant change IMM and I took it as a 30-40WHP gain with no other change. (also ended up going with a Stronger aurora ignition after that lol)

Thank you Rob. That means a lot coming from someone as accomplished with our cars as you.

I keep telling my friends about the "monster motor" I'm going to build for the Scamp. It is compared to the N/A motor in it right now, but nothing compared to what you have done. My end goal is roughly 300 hp. Not really a "monster", but should be tons of fun in a 2300 lb L-body...

The combination as I have parts lined up is as follows:
2.5 CB
782 head with mild port job & back-cut valves
2 piece intake
52mm TB
FWP 50 trim turbo
+20 injectors
3 bar MAP & tune

I plan on running 16-18 psi on the street. This isn't a drag motor, it's supposed to be a fun street motor.

[tryingbe]

My end goal is roughly 300 hp. .

The combination as I have parts lined up is as follows:

+20 injectors

Skip the +20 injectors and get yourself some 65lbs or bigger injectors. I made 250whp at 15psi using E85 and 290whp at 20.5psi on E85. You'll run out of fuel with +20 injectors very soon with your goal of 300hp. 65lbs injectors will allow you to have plenty of room and can use E85 in the future if you choose to. All you need are wideband sensor and a calibration.

http://racetronix.biz/itemdesc.asp?ic=17113814&eq=&Tp=

[83scamp]

Skip the +20 injectors and get yourself some 65lbs or bigger injectors. I made 250whp at 15psi using E85 and 290whp at 20.5psi on E85. You'll run out of fuel with +20 injectors very soon with your goal of 300hp. 65lbs injectors will allow you to have plenty of room and can use E85 in the future if you choose to. All you need are wideband sensor and a calibration.

http://racetronix.biz/itemdesc.asp?ic=17113814&eq=&Tp=

I really have no want or desire to run E85, but thanks for the input. Those really aren't much more than the +20's, so worth considering...

See, this is why I love discussions like this...

[mopar-tech]

I would be curious to know what turbo you were running during this swap? Also, what MPH gain that came along with the lower ET?

60-1 with a .63 housing with a stage III wheel.

BTW- The Reliant when it was running a 2.5 had a perfect 1:1 ratio of boost pressure to exhaust backpressure.

The MPH I'm unsure off the top of my head, I'd have to dig through some timeslips.

[Shadow]

60-1 with a .63 housing with a stage III wheel.

BTW- The Reliant when it was running a 2.5 had a perfect 1:1 ratio of boost pressure to exhaust backpressure.

The MPH I'm unsure off the top of my head, I'd have to dig through some timeslips.

Interesting; was initially thinking that maybe the turbo compressor was too small and the jump to 3" hard pipes too much, as I would have expected a more significant change, but def not the case with that size of turbo.

Couple things to be kept in mind;

You are only talking about a 1 piece to 2 piece swap, even if the 2 piece was well ported for the time, it still has its limitations,

Would also need to consider just how much porting/modding had be done to the 1 piece prior to swap.

I'm sure that you welded a larger neck on the 2 piece, as it can't support a 58mm TB "as is", but how much further did you go on it?

I remember when I first got on the net back in 2004. (IMS) It was right after we built a mid 11 sec full bodied S/C for a member on TD. He was getting flamed for us using two stock y-piped I/C up front because the word was the stock I/C Sucked! lol (getting flamed well Before the car went mid 11's so easily leh!)

When he told them that we ported the Upper 1/2 of his 2 piece intake it was worse! When I got on, I explained Exactly what we did, why we did it and How. A few ppl Got it after that.

The Voodoo they thought they saw was from a comment made in earlier years that porting the area around the gasket that separates the upper and lower sections of the 2 piece is a Bad idea. ie. when you open that area up to gasket size on both sides of the intake 1/2's you crate a "bulb" in the runner and ruin the Tuning of it. (Of course, This I totally agreed with)

So when they heard "ported the upper half to the size of the gasket" they all shat the bed, assuming we did exactly what they believed you should Not do.

Here's what we actually did;

Found a ball that was Just smaller (1/16") then the gasket opening. Ported the upper 1/2 runners till the ball rolled through all of them. Then proceeded to port the lower 1/2 Extensively to crate a "funnel" down to the head. There was some extensive welding that had to be done along the way to support all of this porting and enlarging of course. When done, we still only used a 52mm TB because that is the size that the well ported factory neck could support. (+ I believe Ohio Rob had already made 500HP through the 52mm TB on his 2.4l by that time, or maybe not?)

So thinking on when you did this 1 piece to 2 piece swap, I wondering if you did as extensive of a job on the two piece as what I'm describing here?

The 1 piece has a Brutal restriction right behind the inj bores that I blew wide open when I built the modded 1 piece that is still on the Charger today. The stock 2 piece is only a Little bit better in that area and needs welding all around it to support a Proper size to flow what even a mid ported head can support. A 58mm TB wouldn't be much use IF those restrictive areas were not addressed.

The 1:1 ratio doesn't surprise me in the least. The Charger was almost a perfect 1:1 last time out on 39psi with a stock ported turbo mani

[GLHS60]

""The 1:1 ratio doesn't surprise me in the least. The Charger was almost a perfect 1:1 last time out on 39psi with a stock ported turbo mani""

Just so there is no confusion in the "slightly ported 1 pc" thread:

stock ported turbo Exhaust manifold!!

Thanks
Randy

[mopar-tech]

I'm sure that you welded a larger neck on the 2 piece, as it can't support a 58mm TB "as is", but how much further did you go on it?

Intake was from Steve Calder and it was an "all the way" piece that sounds very much like yours. Lots of welding down near the bottom with countersunk allen fasteners, the lower is ceramic coated, the upper is opened up to gasket size and tapered like a trumpet opening and has a mandrel bent neck with a smooth radius welded in place of the stock 90 degree and a billet fuel rail.

I'm of the opinion the biggest issue (at least on my car as I was running it) is the plenum size and runner length, after all the runners are tuned for maximum filling at a fairly low rpm (5200) and even with higher boost this pressure wave effect is still very much in operation. There is also a secondary wave that is related to plenum volume. Porting will alter this somewhat but you are just tinkering around the margins.

Based on a conversation with one of the engineers who was working on the 300 hp neon N/A engine in the Supercar Sedan touring series I was thinking about making a number of spacers of different thickness to go in between the two intake sections. They had outstanding gains varying the length and found a substantial gain altering the stacks... 11 mm.

The 1:1 ratio doesn't surprise me in the least. The Charger was almost a perfect 1:1 last time out on 39psi with a stock ported turbo mani

I have a video you might like to see- I added a second "cluster" to the Reliant and pointed a camcorder at it for a poor mans data logger. There were also a number of pressure gauges in the frame with taps located in the turbine outlet, turbine inlet, port number one, and boost pressure.

Illuminating.

[Shadow]

Intake was from Steve Calder and it was an "all the way" piece that sounds very much like yours. Lots of welding down near the bottom with countersunk allen fasteners, the lower is ceramic coated, the upper is opened up to gasket size and tapered like a trumpet opening and has a mandrel bent neck with a smooth radius welded in place of the stock 90 degree and a billet fuel rail.

I'm of the opinion the biggest issue (at least on my car as I was running it) is the plenum size and runner length, after all the runners are tuned for maximum filling at a fairly low rpm (5200) and even with higher boost this pressure wave effect is still very much in operation. There is also a secondary wave that is related to plenum volume. Porting will alter this somewhat but you are just tinkering around the margins.

Based on a conversation with one of the engineers who was working on the 300 hp neon N/A engine in the Supercar Sedan touring series I was thinking about making a number of spacers of different thickness to go in between the two intake sections. They had outstanding gains varying the length and found a substantial gain altering the stacks... 11 mm.



I have a video you might like to see- I added a second "cluster" to the Reliant and pointed a camcorder at it for a poor mans data logger. There were also a number of pressure gauges in the frame with taps located in the turbine outlet, turbine inlet, port number one, and boost pressure.

Illuminating.

Pretty sure I saw that video a while back, but it was very hard to see the gauges clearly. Still very Cool and Great way to really get a good picture of what's going on.

I remember the first run on the Charger after installing the pressure tap in the exhaust mani while it was still running the stock cam. Was getting ready to do a BtB swap to the FWD F4 and Had to know how bad my boost to exhaust ratio was before final consideration. Many back then believed it would be 3:1 or worse because I was still running the ported stocker exhaust And the small 9cm Holset turbine housing.

I have to admit, I was expecting close to 2:1 myself and was Shocked at how low it actually was! (1 1/4:1 or less @ 38psi through full 3" exhaust seems to ring a bell) Slapped in the F4 and picked up some Major gains!

After that I hounded several members for several years to get pressure taps in their set-ups!

Interesting on the intake. I always wondered how far you had gone on the inside. Only because I remember reading something that suggested it was fairly stock, but I couldn't overlook that "stealth" mandrel neck you added

[MILKCARTON]

Funny how when I leave a thread, it dies.......