I have a 94 SE-R and I keep on hearing about how the lowports suck and how the high port is better, but my question is: If the hp and tq rating is the same and it is as responsive to the normal bolt-ons then why is this lowport such a bad thing? Any people with real facts please answer this.

Just drop in a 91 cam and you'll be smooth sailing in your low port.
check out www.se-r.net SCC article:
http://www.se-r.net/about/sentra_se-r/scc/dec97/index.html

It is my belief that the head does not suck. Its the camshaft they put in starting in (correct me here if I misspoke) the '93.5 model SE-R.

Is that right? Didn't they make the change midway through the model year in 93? Or was it just in '94?

HMMMMMMM. I have never heard that the cams aren't good. I have the S3's anyway so if is the case that the cams suck then I should be ok. I will running a local dyno on my car soon and I am curious to see what I pull versus a 91-93 with the same mods. I wonder if this dyno will prove this lowport/highport theory either way.

isnt it also that the highports flow better at hi rpms because of their shape

i've been wanting to ask:

are the 91 cams better than the 93 cams???? or are they the same from 91 to 93????

That's what everyone says, but the lowport has shorter runners. So, it's kinda a trade-off either way.

It's my opinion that even though the air takes a slightly sharper bend at one point, the gas in the runners comes into the cylinder more atomized, therefore producing a superior mixture. This is opposed to the high port having more time deatomize. That would make sense, considering they were supposedly having problems with slight deatomization hurting emissions.

I could be wrong, my internal combustion engines class has got my brain working overtime in this debate.....

I just know from driving both that no matter what the mods, highports are MUCH more enjoyable to drive. They feel torquier, even though they really aren't. I've driven two full bolt on B14s (eric96ser and jacen99SE) and I prefer driving my stock-with-open-airbox 93 NX2000 any day to their full bolt on lowports.

Originally posted by eliterit
i've been wanting to ask:

are the 91 cams better than the 93 cams???? or are they the same from 91 to 93????

They are the same.

I *think* the cams were changed for the '93.5 model, and then again for '94. The cams were the same for 95+, but the redline was lowered and a speed limiter introduced.

For some reason, lowports can achive slightly more hp vs. a highport given the same mods (cams, cai, header, ECU, etc.). I don't know why this is, I've been trying to wrap my brain around it for some time now. All I can come up with is the lowport engines are newer and in better shape than a 10+ year old engine.

And they certainly have less emmisions crap to go bad. My '92 is a freakin maze of hoses/wires all running to various emmisions crap.

Originally posted by Ben98SentraSE
I just know from driving both that no matter what the mods, highports are MUCH more enjoyable to drive.

Isnt that the truth. My 94 started off as a lowport and I thought it was a blast. Then I swapped in a highport and I wouldnt go back.

:cool:

The intake cam was changed for the '94 car. The exhaust and intake cam were changed for the '95 car. The cams were the same until either '98 or '99, when the intake cam was changed for emission reasons.

Here are my two cents. You can't say that the high-port is better because the low port makes the same amount of power stock. And that's with the smaller lobes on the intake cam. I have no idea why, but doesn't that translate to a more efficient engine. Smaller cam and yet the same output. That is the reason why a low-port engine responds to mods better. Any comments? I would really like to get to the bottom of this never ending question.

Martin

Well, Im a believer in the Primera STILL having 9:5 compression.
Just from talking to certain people about it and seeing the stock dyno on a JDM. I think my high port did great with just CUSTOM mods and a Pacesetter header. I beleive I can bust the 140 mark with newer plugs and advanced timing. Apparently, my timing was still at 15 on my last dyno of 139. :mad: :mad: :mad:

Originally posted by Ben98SentraSE
I just know from driving both that no matter what the mods, highports are MUCH more enjoyable to drive. They feel torquier, even though they really aren't. I've driven two full bolt on B14s (eric96ser and jacen99SE) and I prefer driving my stock-with-open-airbox 93 NX2000 any day to their full bolt on lowports.

damn, stop makin me feel bad :(

:D

Here is what I KNOW:

1. The port and only the port was redesigned for the 94 model year. The cams stayed the same. There was no change. After all the 94 is still an OBDI model car. The 94 model became a low port and the 91-93 were still high ports.

2. In 1995 the cams changed. I believe it was only the intake cam that was changed and the exhaust stayed the same. The redline dropped to 7100 and there was a speed limiter. OBDII was introduced on these SE-Rs

3. In 1998 the cams DID NOT change, but more emission crap was added on the top of the throttle body and under the rear left back side of the car you have black canister box connected to the gas tank for emissions. There was a post a long time back when someone compared the cam part numbers for the 98 and the 95-97 and found them to be the same.

4. The shorter intake runners on the 91-93 engine help with better top end power, but the longer intake runners on the 95-99 engines produce more bottom end torque. On my ex-low port engine the car produced 147 hp and 132 lbft of torque with full bolt-ons S3 cams sans JWT ECU. On the high port primera 10:1 compression engine that I am running now the same set-up but with S4 cams and JWT ECU does not even hit 130 lb-ft (129.6), but produces around 152 hp. These 5 additional hp might be caused by the bump in compression or the ECU. Also the alignment on the car is now more radical than before. 2.7 negative camber and 1/8+ toe-out cost about 3 hp.

I would like to test the car with a street alignment to eliminate the aligment as a variable from the equation.

There has alway been this bias in favor of the 91-93 high port engine among Classic owners. I hate to rain on your parade, but both engine are very close in hp when modded.

im not sure why, but the general consensous has always been that the hi port is somehow better.... i agree though that its definitely more fun to drive..... i drove PlanoSER's car and we ran within 1/1000th of a second of each other in the quarter, and i liked the power delivery of mine much better.

Here is what I KNOW:

I remember a post some time ago (a year or more) where someone broke out the FSM and found the specs on all the cams. I though I remember them stating the cam was changed in for the last half of the model year in 93, and again for '94 (perhaps it was 95), and then remained the same past '98.

did a search, couldn't find it. It was a while ago.....

Originally posted by nj1266
1. The port and only the port was redesigned for the 94 model year. The cams stayed the same. There was no change. After all the 94 is still an OBDI model car. The 94 model became a low port and the 91-93 were still high ports.

As an addendum, the '94 Infiniti G20's (and obviously, subsequent model years) were OBD2.

Originally posted by MaddMatt


I remember a post some time ago (a year or more) where someone broke out the FSM and found the specs on all the cams. I though I remember them stating the cam was changed in for the last half of the model year in 93, and again for '94 (perhaps it was 95), and then remained the same past '98.

did a search, couldn't find it. It was a while ago.....

I think you are right. In 94 the cams did change. I was wrong in my post. Also in 95 the exhaust AND intake cams were change.