Whup, never mind about the rotors- question answered earlier...

The cat is a real eyebrow lifter for me..
I'm curious, Id love to see what would happen if you slapped in a test pipe just for kicks and redynoed it....


Well, It's pretty evident that the intake represents a large restriction.. those runners are damn small too.
Nice job!

 

The NA's I've seen cannot get over 160 with the stock exhaust manifold.
With the header, it'll hit 16x no problem.
I have to disagree with you on that.
And yes, it's noticable louder; louder most of the time will imply more power.


-Ted

 

You have much more experience than I do, no question... I have seen a few dyno comparisons of headers and only seen a few HP difference- not worth the noise IMO.
When I put my headers on I only noticed a tiny difference in the extreme top end. I definatly dont' think it was more than 5 hp.
It might depend a bit on the brand... I remember a little while back a guy did an comparison with an engine dyno, and tested the peice of garbage Pacesetter header (They aren't even equal length, that's what killed them) and they actually lost power over the stock exhaust manifold. RB headers gained power, but I dont' remember it being more than a few HP.
Everything I'm saying here I've just heard from others' experience, I've never seen any first hand except one time with my own butt dyno.
It still appears that it's the intake that represents a huge restriction once airflow starts to increase! Wow.

 

Icemark,

I think a set of pulleys and an aluminum flywheel is a welcome addition to your car...any plans?

 

Daily driver, so the light steel flywheel I have is all I am going to do.

I have been considering light weight pullies though.

The next thing will probably be either an aftermarket ECU or an add on. Depending on how well I can still meet emissions and how many FC parts (like the new block off plates, or wiper switches, or colored light Logicons) I can sell on my website. (shameless plug)

 

I am gonna have to agree with Bambam, with headers I have only seen a couple of HP difference on other FCs ( unless they do a true dual setup) when comparied to a downpipe.

And again the noise is 1000% louder.

 

Yeah the stock S5 runners are much worse (smaller) than the S4 intake runners. One of the reasons I think my matched and polished through extruding hybrid between the two works better.

The S5 VDI section and dynamic chamber sections are now much much bigger. I probably am loosing a little on velocity because of it, but seem to be gaining it back in flow

 

whoops double post

 

I think there's a lot of variables involved when modifying an NA.  It's hard to make a direct comparisons when you need to worry about spark plugs, spark plug wires, Zenki versus Kouki intake, porting, fuel computers, etc. - different combinations can get you a surprising result.

A good example of this is cymfc3s's FC turbo that run upgrade turbo + 1600's in the secondaries ON THE STOCK ECU!  Most people would think this would be impossible, but it ran and put down almost 300hp at the wheels!

I've been talking to another forum member, and this combinations seems to be very popular down in the South:  60-1 turbo + 1600's secondaries + stock ECU!

Hey Icemark, was it on a DynoJet?  I don't think I saw you mention this?


-Ted

 

yeah, it was a dynojet. I don't think I mentioned it, but it is in the screenshot of the curve that I shrunk to post

 

Just because something can be done, doesn't necessarily mean it should be. The words crude and inefficient leap to mind...

 

CONGRADULATIONS ICEMARK!

Those are great dyno #s.

We really don't have any reason to doubt the dyno #s are correct, and even if they are a bit high it does not matter a bit as it seems you are very happy w/ your car.

I know that having someone (you in this instance ) hand assemble the motor and its components while carefully porting and matching components can add up to great gains.

They say NA piston power is all in the head work, so it makes sense that a large portion of NA rotory power can be gained in the porting and intake manifolds.

About the headers-

The Racing Beat catalogue itself mentions that headers do not provide a significant gain over a "racepipe" when using stock intake/ fuel injection system.

The 1986-92 13B 6-Port engine, in stock form with the factory fuel injection, produces similar power gains with either our Heaer/Presilencer combination or our Cat Replacement Pipe/Presilencer combination. If you have no intentions of installing our Holley Intake System, we recommend the Cat Replacement Pipe/Presilencer combination since it offers a slightly quiter exhaust note, is easier to install and is less costly. If you are intending to upgrade the intake or fuel injection system, the Heaers/Presilencer combination offers the greatest performance potential.

So, it appears that the collected headers really work well w/ the short runner intakes to make the power on the top end.

A true dual system would be a whole 'nother can of worms as it works off different princapals of operation (no collection/scavenging).

Now Icemark- find a way to lean that sucker out and add some aggressive ignition advance. When my TII was running NA it liked ~13.5 AF ratio and over 40 deg of advance in the low end tapering to ~30 deg advance.

 

so u switched from a turbo to NA because it's a lot lighter? what if i was to get a vert and get a jpec motor? is there anything i can do to get the curb weight below 2900?

 

Uh, I can downshift from 3rd to 2nd in my rx7 and break the rear end loose with an s4 n/a.... Headers/3inch all the way back, no where near emissions legal, with a stock port and no rebuild. If i start easy in first and shift hard to second i can spin all the way up to 3rd and then chirp... I don't know what all this talk about n/a's not spinning tires is :P

-Mike

 

It's funny, but you can change around the setup to get less noise and still keep the power, It's all about what muffler(s) you choose, catalytic converters, (or pre-silencers) and silencers (at the muffler tip). You can cover up that sound increase in other ways.

 

Hmm... I am not so much interested in doing that but I don't think I can spin my tires all up to 3rd or even on 2nd on my S4 vert (w/ RB header/pre-silencer/cat back). 5/6th ports are working and compression was okay (when I bought it). So, I guess mine is probably in the 130-140 rwhp range....

Anyway, good work Icemark!

 

None taken. I really wasn't thinking about emmisions regulations when I was compairing Icemarks HP number to the Renesis.

I was (and still am) a little shocked by the power Icemark has attained with his project. To get that kind of power out of a stock exhaust manifold still seems improbable to me.

 

Have you taken any measurements on the intake runner diameter before and after the extruding?

 

For these comparisons, was the engine that was tested a stock block or ported block?

My experiance with headers is that they don't really add much noticalbe power until the exhaust port has been enlarged.

When I ran my S4 stock block, I was disappointed when I installed the RB header. With my new engine, I've run it with the stock exhaust manifold and the RB header...The difference was noticable.

 

it actually worked great, yes its prolly not the smatest thing in the world but it did surprisingly well. stock drivebility too

 

yeah it seems like on an other wise stock s5 the headers vs the stock exhaust manifold doesnt do much. todds car did 140rwhp with the headers, rarest did 142 with the manifold. the its car is in the same boat, the air has to go into the engine before it can come out

 

Icemark, awesome numbers. You really did a great job with your car, but I'm guessing you would still point someone like me (not exactly a car expert) toward a TII swap for more power, despite the extra weight, rather than the extensive and expensive work you've done?

Oh, and if you and Rarest ever race, MAKE A VID!!!

 

And again, As Dale and I have talked about, the condition of the motor itself has radically more to do with it than anything else.

Not to beat a near dead horse (sorry kevin), but remember that Kevins GTUs even with its higher compression rotors, is still 10 PSI lower on actual tested compression than my motor.

That is a considerable amount when you are comparining the two. I am sure Kevins with his compression back up into the upper 100teens or low 120s would be much more powerful.

 

But remember also that pre-silencers tend to cool the still expanding exhaust mixture on a non-renisis rotary faster than a straight pipe, or even a cat.

So on things like changing the exhaust exit volicity, a silencer or pre-silencer can cause all sorts of changes to the actual exiting of the exhaust gases.

 

damm double post again