pd_day

iTrader: (6)

On my NA, it pulls from 2.5k all the way up to 7k and it drops off.
Is this the norm? If I want to redline it, it takes long to reach redline in 3rd gear. Is this normal?

I keep on hearing people pulling to redline strong? What's the deal?

Erik

any n/a FC i've been in starts to slow down around 7500 rpms...and these have all been WITHOUT headers. the 2 i've been in with headers rev up all the way and keep going. now, i'm not sure if this is due to the car itself, or that actual mod of letting the exhaust pulses spit out and flow more evenly. ever since i've had my n.a (close to 3 yrs now), it revs perfect up to around 7600, then sorta struggles to 8K (if it even reaches it).

i'd " think" that if mazda put an 8K redline in the car, it should reach it no prob. hell, my gf's civic hatchback will bounce off the rev limiter all the time. but then again...this IS an rx-7...and when does anything on it make sense?

rico05

Yeh, mine will only hit 7k nicely. Hey Erik, how does that header sound? I know a guy who has a Dynamax catback, and a pacesetter header, and it sounds like a damn weedwhacker.

pd_day

iTrader: (6)

hey Erik, how does your NA pull?
All the way to the redline with the N1 and bonez front section?

mazdaspeed7

pd_day, do you still have stock cats? They might be somewhat clogged. That happened to me wneh my car was almost stock, and it felt down on power everywhere, but especially on the top end.

You can see my mods in the link in my sig. My car pulls to the rev limiter at 8800 with no problems. Its still pulling hard at the rev limiter.

Erik, you are right about the stock manifold killing top end. The exhaust pulses are hitting a flat wall after leaving the exhaust port. The outlet onb the stock manifold is on the side, with nothing to help motivate the pulses straightinto the exhaust. Very good for noise reduction, very bad for top end power.

If you need to worry about emissions testing, get headers-->high flow cat-->good cat back. Then worry about intake and pulleys.

pd_day

iTrader: (6)

No, I don't have stock cats
I replace the 3 cats with a dual cat Catco system. I was told it was high flow, but I've heard they are just stock replacement.

I am debating on either a racepipe or header. From my massive reading, they produce around the same power on a stock port engine but the header is 10000x more louder. However, on a ported engine, the power from the header will give WAY more power.

Is this correct??

Thanks

Erik

yeah man...it still pulls great...i had the ports adjusted and fuel injectors cleaned in aug so it had a nice tune up. its just at around 7500 is sorta hits a flat spot like adam said. up until that point though it feels great.
i still have the stock manifold so i'm like 90% sure thats whats slowing me at that point. even the rotary mechanic i go to didn't really have an explanation (and Ito knows his **** ) he was just like "well man, i dunno what to tell you...i adjusted everything i could to make it run perfect...just get a header and it'll clear everything up"

also, i've never been in a car with the racing beat headers...only pacesetter. vosko has pacesetter. i don't think the sound is too weedwacker like. not as deep as mine with the N1 but definately sounds nice

Erik

oh, and get a header...the racepipe still utilizes the stock manifold...and thats where the trouble lies. the header replaces that stupid "box"

pd_day

iTrader: (6)

Aww....then I can't run in "STEALTH" mode anymore from all the noise

pd_day

iTrader: (6)

But then I have thrusters that spits fire

mazdaspeed7

The difference in the powerband between race pipe/stock manifold and headers is where the power falls off. Headers extend the powerband. Power doesnt fall off as soon, and it doesnt fall off as drastically. But up until the power starts to fall off on the race pipe, the power levels are about the same.

If you get headers, get a presilencer in the midpipe. www.racingbeat.com makes excellent headers, thats where I got mine from.

Im curious about this engine. How many miles on it? Ever rebuilt? Have you checked the compresson? That Si and the Integra might have been chance encounters with modded ones, but it still makes me wonder if your car is up to par.

pd_day

iTrader: (6)

This engine was a mazda reman that I put in last June when I got the car. There are 15k miles on the engine now.

At the time of the races, my TPS was not set properly and won't pull to 7k. It would hesitate around 6800 RPM.

Since than, I've adjusted the TPS to spec, new fuel filter and can hit 7.5k RPM no problem now with occasionaly hesitation around 7k RPM.

I am thinking that my injectors are dirty. I am going to try some redline fuel injection cleaner to see if it helps. It all else fails, I will put the injectors out for cleaning.

pd_day

iTrader: (6)

Just came back from my lunch break.
When I drove out for my lunch break, I tested the redline again. It wouldn't redline in neutral. Something is wrong. Adjusted the TPS, now it redlines in neutral, but hard if in gear. Symptoms of clog cat?

mazdaspeed7

It really does soundlike clogged cats. Do you have an air pump? if not, Im sure its clogged cats.

pd_day

iTrader: (6)

Yup, have the air pump. And the ports open probably. I can feel the surge at 5500RPM

SpeedRacer

Headers, definently make your power dropoff slower and later. With the mods in my sig, I pull to 8 easy, and then around 8500, power starts dropping off, but not drastically. Before I had headers though, I could still take her to 8000 pretty easy, just not as quickly.

pd_day

iTrader: (6)

Right now, 3k to 7k is fast, then 7k to 8k takes a while.

mazdaspeed7

The 5000 rpm surge youre feeling is the VDI. You should check to see if your 6 ports are working. Someone else is going to have to give a good way to check them b/c I havent had the 6 port sleeves in my car for nearly a year. It might be worth the effort to take the whole intake manifold off so you can take the sleeves out and clean them good, and do something to them to smooth out the transition into the chamber. If you dont mind not having the sleeves at all, I will be making a round of nylon inserts that replace the sleeves, and smooth out the transition into the chamber. The 6 ports end in a dead end, which is horrible for power. I have those nylon inserts in my car, and I was very impressed by the gains. A lot more power everywhere, compared to working 6 ports.

pd_day

iTrader: (6)

Got home and tinker with the TPS again.
Finally set pins

idle
1 and 4 at 4.3k ohm
3 and 6 at .79 ohm

wot
1 and 4 at .69 ohm (can't adjust this)
3 and 6 at 4.3k ohm

I think my injectors are dirty so I got out and brought a bottle of redline fuel injection cleaner. Put in 3/4 tank of gas and did 2 hours of kamakazi highway driving.

After the drive, I can hit 8.5k RPM in neutral now from 7900RPM before cleaning
And the car will pull nicely to 7.5k RPM now from 6900RPM with hesitation before.

Does the numbers sound good?

I highly recommand this product.



Now I just need something to verify this so I know it's not just in my head.

Matt22

iTrader: (10)

The best solution to clogged cats is straight pipig the bitch.
hey does a seven have a rev limiter. in neutral revs go all the way to 8.
in first thru third it will do the same slows slightly in third around 7600.
but makes it to 8000. fourth and fifth i haven't reached yet. I suppose i could right now with how bad my clutch slips. ****. anyways Lates
Matt22

mazdaspeed7

Pins 3 and 6 are the ones to check. Here is how to adjust it: take 2 paperclips, push one ond of one into the BACK of the connector for pin 3 and the other one in pin 6. Leave it plugged in. You should get a voltage reading at idle. Adjust the screw until the voltage is exactly 1V.

pd_day

iTrader: (6)

Thanks, I'll go check now

pd_day

iTrader: (6)

ok tps set, fuel system cleaned.
Car runs fine now.
1st, 2nd, 3rd gear redline no problem. (4th and 5th will get me in jail)

Everything went good.
Got out today and tested my 0-100km/h time (0-62.5mph)
I have a 10inch sub in box in trunk ~35lbs
An amp ~10lbs
1/2 tank of gas
I am 180lbs
misc in bins and glove box ~5lbs
so the car probably weights in at 3150lbs

I timed my runs in the most primitive way, I used my CD player.
1st run, launched at 3000rpm, spun in 1st for 1 sec, shift at 7k, 0-100km/h was 10 sec.
2nd run, launched at 3500rpm, spun 1/2 through 1st, shift at 7k, got 9sec
3rd run, launched at 4000rpm, spun 3/4 through 1st, shift at 7.5k, got 8.5sec.

Is my car healthy?

I'll take out everything next time, and see if it will make a difference.

pd_day

iTrader: (6)

Ok, took out all crap from bin, glove box, took out sub, amp and car has 1/4 tank of gas.

Put 94 octane gas in the car.
Ran it a couple of times.
The car actually hit the buzzer in 1st, 2nd and 3rd gear easily.
Before with 87 octane, power would die around 7000 RPM with hesitation, but with 94 octane, it pulls nicely to 7700RPM and power drop off is not as sharp as before.

I've read that NA run best on 87, how can you explain this phenomenom?

Thanks

mazdaspeed7

Have you messed with your timing? Advanced timing requires a higher octane gas to prevent detonation. The fall-off in power could be from minor detonation, and the higher octane gas would prevent that.