pacesetter header, individual throttles, estimated outputs ?

[InsanityInc]

As an aside, my ECU cuts fuel at 6500, this is what I gather to be the redline on an S14, as I've tried both auto and manual ECUs.

In butt-dyno driving, there's no more on top than there was with the stock intake manifold. Again, there may be a few HP difference, or the curve might not start to drop at 6300, but there's really nothing there to claim the stock intake manifold is a restriction. My stock setup rapped the tach needle pretty convincingly, the dyno sheet shows flat power from 5700-6400. Compared to your stock dyno sheet, my engine is up 25hp at 6000. Maybe something wrong with the engine your stock sheet was based on?

As to the 1/4, I'd very much like to. However, I've relocated my battery and LACR wants an external disconnect that will shut off the car. I'm not going to run all that wiring just to take a 1/4 mile pass.

Nothing wrong with the engine I posted, it's the same as every stock KA dyno I've seen. Also, it's up horsepower on yours because you have a different exhaust. Exhaust modifications provide substantial gains to KAs. Though, it's more the locations of the torque and power peaks that I'm looking at, and as you can see, even on your engine the torque dies a nasty death very early.

Also, 6500 rev limiter is an S14. S13s have the limiter set at 7000. That means your intake manifold doesn't have secondary butterfly valves, either, which would account for the slightly flatter top end (though if you look at your torque curve, that could definitely stand to be pushed much higher).
Modified by InsanityInc at 1:56 AM 6/27/2005

[SSS]

I was also surprised I had to lean out the mixture. I don't know why this is, but assume the stock fuel maps are safely rich from the factory. I didn't have the WBO2 setup when I was running the stock manifold.

From that pic it looks to me that the MAF you are using is nearly identical to the Z32 maf; does it converge into a small diameter hole like the aluminium bodied U12/S13 mafs?

Whilst i agree with you regarding nominal gains on a stock KA by using ITB's, a cam'd KA will heavily take advantage of the shorter runners and increase in cross sectional throttle area.My fwd KA24E made peak power at 6000rpm using a custom 262/264 cam i had ground, the only intake mods at the time being a modified airbox inlet and a K&N panel filter; exhaust consisting of 4-2-1 headers and a now very anemic 2" mandrel bent cat back, with the stock cat and flex pipe.

I expect very large improvments in top end with:- GSXR1000 ITB's w/custom plenum- 3" intake pipe with a Z32 maf being fed by a K&N pod just outside the engine bay (residing where the intake resonator box used to be)- 3" exhaust w/mandrel bends (i'm fabbing this up myself, so it'll cost me maybe $50 at best)- 3" cat and 3" flex pipe

Tuning is done by re-mapping the std ecu w/ an xtronics romulator.

With some careful ignition tuning, i don't expect to loose much low end torque, due to:a) the size of the throttles (43mm)b) re-mapped timing

By using the 43mm throttles it's hoped that the intake velocity will stay the same as or faster than the stock intake manifold without becoming too turbulent and aiding in quicker cylinder filling.

[s1ndicate]

pacesetter, a good header? I have it on my SOHC, I do not like it at all. Iam thinking of moving to a hotshot or something better or even back to a stock unit.

[sticky240]

what don't you like about it?

[s1ndicate]

Bad fitment, its rusted to hell, didnt feel a power gain at all. The design looks like it was made in someones backyard.

When we went to put it on, it bolted up to the head alright, cat also, the biggest problem was that you couldnt turn the wheel?! The header was preventing the wheel from turning and it was catching, so the header had to be beat and beat to no end to make it work. Oh ya, also all the painted melted off of it within hmm, few minutes.

[Julian]

Though, it's more the locations of the torque and power peaks that I'm looking at, and as you can see, even on your engine the torque dies a nasty death very early.

Nasty death VERY early? Are we looking at the same dyno sheet? STOCK, my motor puts out AT LEAST 125 ft/lb from 3500 to 6000. That's pretty fine. No, it's not some high-rpm screamer, but it was never designed that way, and there's only so much you can do to improve upon it.

The intake manifold still takes too much blame from you. I think you're doing people here a disservice by blaming it for anything. Aside from the fact there isn't a bolt-on alternative, ITBs on a stock motor have not shown to be an appreciable improvement.

[InsanityInc]

Nasty death VERY early? Are we looking at the same dyno sheet? STOCK, my motor puts out AT LEAST 125 ft/lb from 3500 to 6000. That's pretty fine. No, it's not some high-rpm screamer, but it was never designed that way, and there's only so much you can do to improve upon it.

The intake manifold still takes too much blame from you. I think you're doing people here a disservice by blaming it for anything. Aside from the fact there isn't a bolt-on alternative, ITBs on a stock motor have not shown to be an appreciable improvement.

Your engine isn't stock, for one. For another, losing 15% of your torque by 6000 isn't great. Also, your stroke doesn't mean the engine can't BREATHE at higher rpms, it just means it can't get there without breaking. There are plenty of engines with the same, if not larger, strokes that breathe that high much better. Also, I've showed you a cammed dyno, and it doesn't get much better. You tell me what else the problem could be? I'm open to suggestions. I don't think i've ever seen a dyno of a KA making peak power @6000+, except the nismo one which is magically 2600rpms higher than that.

[oneline180]

have you guys thought about running an itb setup with idn something like 11.8/1 compression (as in SOHC Pistons) ???

its just a thought.

[midnightsliding]

hey matt, im currently working on an itb setup for my s14. i used the stock manifold, gsxr itbs, and a 'custom', made by yours truly, aluminum plenum. reason for the plenum is because i want to run the maf for now atleast. it should be done tomorrow. i cant wait! ill let you know how it turns out. if you would like to check it out sometime, id be more than happy to show it off.

hey j-z can u IM at AIM: sectionei8ght, i wantto talk to u about ur setup, thanks

[Nismo_Freak]

Take the SR20DE and SR20VE for example. Obviously the VE is designed to rev higher. Thus, the intake manifold runners are shorter. It does make a massive difference in high-RPM breathing.

The SR20VE also has secondary cam lobes that have alot more duration and lift than even the "hot cam" B13 SR20DE's, not too mention the CR is also higher by a good amount, and the head design is much more efficient.

The SR20VE is in a different ball park compared to the SR20DE.

Poor comparison.

[InsanityInc]

The SR20VE also has secondary cam lobes that have alot more duration and lift than even the "hot cam" B13 SR20DE's, not too mention the CR is also higher by a good amount, and the head design is much more efficient.

The SR20VE is in a different ball park compared to the SR20DE.

Poor comparison.

It wasn't a comparison. I was using it as an example to show that the length of your runners does affect the operating range of your engine. Why would nissan change the manifold for the VE if it didn't? The VE could rev higher due to it's cams, so it got shorter runners. For all intents and purposes, the VE is the exact same engine with different cams. But just like with a KA, if they would have JUST fiddled with the cams without touching the intake manifold, the gains would have been incredibly paltry.
Modified by InsanityInc at 9:23 PM 6/29/2005

[InsanityInc]

Hm. I found an interesting link:

http://driftchat.com/forum/printthread.php?t=235

SR20DEs have almost the exact same cam configuration as an S13, yet they have a power peak at 6400. If you look at the dyno of an SR20DE, the torque does the same thing as it does in a KA, just slightly later, and if you look at the intake manifold of an SR, the runners are also slightly shorter.

Also, the SR20VE VVT cams have roughly the cam specs of the JWT KA cams. So obviously there's something fishy going on, and all signs point to the intake manifold.

[j-z]

hey j-z can u IM at AIM: sectionei8ght, i wantto talk to u about ur setup, thanks

i dont have aim on this shltty webtv. you can email me at [email protected], and i can talk to you through that. btw, still not done yet. everything is done besides the plenum. im working on it as we speak though, so it should be up and runnng im hoping by the weekend.

[midnightsliding]

j-z sent u an email, but jsut in case it didnt go through heres mine [email protected] send me one if u didnt get mine and i will reply( i suck at the internet)

[Julian]

Your engine isn't stock, for one. For another, losing 15% of your torque by 6000 isn't great.

You're complaining about 15% less PEAK torque 600rpm PAST the power peak? You yourself pointed out that torque and power pass either other at 5252rpm - you're going to lose torque past that point.

You tell me what else the problem could be?.

I've never suggested I know what the problem is, though the exhaust is the place I'd start. I'm telling you what it is not. You can point to different (but similar...??) engines with different power peaks and the SR line of engines (though I don't see how you get to compare completely different engines yet I can't throw up a dyno sheet of a stock KA with a simple exhaust). _I_ have driven both the stock manifold KA and the same KA with ITBs and I'm telling you the difference, if there is one, is SLIGHT. There's no magical 30 HP.

As I've said, theoretically you are correct. In the real world, as applies to a stock KA and manifold versus a stock KA and short-manifold ITB setup, you are not correct.

I don't think i've ever seen a dyno of a KA making peak power @6000+, except the nismo one which is magically 2600rpms higher than that.

now you have.

[Julian]

Hm. I found an interesting link:SR20DEs have almost the exact same cam configuration as an S13, yet they have a power peak at 6400. If you look at the dyno of an SR20DE, the torque does the same thing as it does in a KA, just slightly later, and if you look at the intake manifold of an SR, the runners are also slightly shorter.

So, a _slightly_ shorter runner (do you have measurements?) moves the power peak nearly 1000rpm? Sorry, there's a lot more to it than that, never mind they're completely different engines.

....of course, maybe that's my problem...with my short ITB manifold my power peak must be 8500rpm.

[InsanityInc]

You're complaining about 15% less PEAK torque 600rpm PAST the power peak? You yourself pointed out that torque and power pass either other at 5252rpm - you're going to lose torque past that point.

Uh. No. You don't even understand the relationship between torque and horsepower and you're attempting to argue this? Your engine can make peak torque anywhere in the RPM band, so long as its parts allow it to. Horsepower and torque CROSS at 5252, that doesn't mean diddly about what they did before or after that number. Just means that HP> torque above 5252 and HP < torque below 5252. The only reason that happens is because horsepower is just a representation of torque/time that uses 5252 equated against rpms, so when rpm=5252 torque=power. The crossing point for kw and nm for example is completely different.

Quote »I've never suggested I know what the problem is, though the exhaust is the place I'd start. I'm telling you what it is not. You can point to different (but similar...??) engines with different power peaks and the SR line of engines (though I don't see how you get to compare completely different engines yet I can't throw up a dyno sheet of a stock KA with a simple exhaust). _I_ have driven both the stock manifold KA and the same KA with ITBs and I'm telling you the difference, if there is one, is SLIGHT. There's no magical 30 HP.[/quote]Once again, dynos of KAs with exhausts are very readily available. The ONLY dyno I have not seen is a KA with a different intake manifold. Nothing else got the results. Also, who said you can't throw up your dyno? I just said it didn't prove d!ck. Not to mention that KAs and SRs are not that different. 10mm of stroke isn't going to completely change how an engine can breathe.

Quote »As I've said, theoretically you are correct. In the real world, as applies to a stock KA and manifold versus a stock KA and short-manifold ITB setup, you are not correct.[/quote]So you have proof of this? Oh wait. You don't. And everyone besides you with an ITB setup says the engine feels far more powerful on the high end.

Also, your engine does not make 140ish@6000. It makes 140ish@5700, and you have nearly the same power at 6000. I have yet to see any non turbo KA making peak @ or above 6000, besides the NISMO one.
Modified by InsanityInc at 1:57 AM 6/30/2005

[InsanityInc]

So, a _slightly_ shorter runner (do you have measurements?) moves the power peak nearly 1000rpm? Sorry, there's a lot more to it than that, never mind they're completely different engines.

....of course, maybe that's my problem...with my short ITB manifold my power peak must be 8500rpm.

Three cheers for retardation. The SR manifold looks about 4-6 inches shorter in the runner department. I don't own one, so I can't run out and measure it for you. Also, 5600-6400 = 800, not 1000. And yes, I wouldn't be surprised at all if that shortening moved the power peak that much. 6 inches is a long, long distance to go at 6400rpm. You're going to hit a point of diminishing returns obviously where your camshafts become the limiting factor, but the purpose of what I was saying was that the s13 240/248 cams are being held back quite substantially by the factory intake manifold, as evidenced by similar engines with similar cams (and JWT/PDM cams are being shot in the foot by the stock manifold). You have an s14 with 232/232 cams, and your stock manifold had no butterfly valves, so I wouldn't doubt that your manifold wasn't holding your engine back nearly as much.

[InsanityInc]

Another interesting thing I found today:

http://fiero.cc/fiero-tdc/members/mws/intake/

Long story short, the GM 3.4DOHC has a similar intake manifold quandry as the KA24DE. So, some guy decided to do something about it. For his efforts, he was rewarded with an extra 65WHP. Yep, 65 WHEEL horsepower from a different intake manifold (to be fair, he also twiddled his stock cams around a bit, so that probably made a bit of a difference). And as an added bonus, if you look at the stock dyno it has an incredibly similar shape as a KA stock dyno, and unsurprisingly so I might add. Why's that you say? Why, we already know the intake manifolds share a similar problem, and the camshafts are almost identical in the two engines:

Cam Specs(From GM)248 degree adv. duration163 degree @ .050".370" lift

(Measured off a set of 94 3.4DOHC cams)Int: 205 Degree Duration @ .050", Lift = .369"Exh: 213 Degree Duration @ .050", Lift = .373"

(from PDMracing)STOCK 91 Cams - Intake - 207 degrees duration @.050”, .350 lift; Exhaust 215 duration @.050”, .367 lift.

My little project is looking even more promising now.

[s1ndicate]

Insanity, whats your point on ^

?

Just cause they are alike in some ways, does that really matter. Iam sure they have different strokes, etc. etc. Which wouldn't that also affect the outcome?

[SSS]

You need cams to compliment the new intake, without them you'll just be pushing **** uphill.

As far as regrinding stock DE cams is concerned, i don't think it would be terribly hard to have spacers or new shims machined up to compensate for the reduction in base circle diameter.

[InsanityInc]

Insanity, whats your point on ^

?

Just cause they are alike in some ways, does that really matter. Iam sure they have different strokes, etc. etc. Which wouldn't that also affect the outcome?

Sorry, but a 10mm difference in stroke isn't going to completely change the physics of intake manifolds. This isn't new information, folks. Intake manifold design has been a big thing in car modifying for a long time.

Quote »You need cams to compliment the new intake, without them you'll just be pushing **** uphill.[/quote]No. Follow the link I posted. He gained 65whp on stock cams. This isn't unusual. The stock 240/248 cams are being restricted by the intake manifold. That's why s14s have the same power in stock form even with 232/232 cams. Nissan realized that the cams weren't doing d!ck but hurting emissions, so they changed them.

[SSS]

If you mean the stock 240/248 cam in the SOHC compared to the 232/232 cams in the DE; there you go, adding better flowing ports and 4 extra valves allowed them to do that.

As much as i would like to be optimistic in a possible intake manifold that could produce an additional 50hp in the KA, i can't see it happening without the cams to suit.

I could never go back to a stock cam in my SOHC.

[SSS]

This is just running a few quick numbers in Engine Analyzer Pro.

Run 1: stock 240/248 KA cams, stock intake manifold.

[SSS]

Run 2: Stock KA 240/248 cam, running GSXR1000 ITB's.

[SSS]

Run 3: GSXR 1000 ITB's, 262/264 cam; the specs i based it are identical to what i run in my own SOHC.

[InsanityInc]

What is engine analyzer pro, for one?

For another, the DOHC s13 cams were 240/248 (s14 were 232/232), and the DOHC engine does have a much better flow capacity than the SOHC KA.

I have to say I'm a bit leery of the accuracy of that software considering what the stock prediction looks like.
Modified by InsanityInc at 6:31 PM 7/2/2005

[InsanityInc]

I found some demo version of that software, and tried making a KA24DE graph. I noticed that the program SEVERELY overestimates the effect of your exhaust system, and seems to create very strange results below 3500rpm or so.

[s1ndicate]

So your saying with a sweet intake manifold design, alot of HP is achieveable?

[InsanityInc]

So your saying with a sweet intake manifold design, alot of HP is achieveable?

Yes, because in order to make more power you have to make more torque or produce that torque at a higher RPM. The stock manifold basically prevents the latter from occuring, and you can only get so much torque out of a 2.4L.