In my NeverEnding quest to improve my rx7. Today I was joy ridding on the streets testing out at whitch rpm i would best change gears at. i believe I felt the power in different areas of the Rpm range. i find this:

with 5/6 ports wired upen on my S4.

power is minimal from idle to 3000 rpms. at 3k rpm to 4k power kicks up about 10 hp. i can feel a press on my back with jsut 1k rpm rise on second gear. At 4k to about 5k power seems to STAND STILL like there is no rise in power. as if the engine is moving and reving up without the pull feeling. at 5k -5.5 power starts to pick up again rising a lil more but it's increase isn't super strong . at 5.5-6.8 Power JUMPS CONSiderably as if another 10 hp just jumped out of it's magic hat. from 6.8 to 7.5 it goes downhill. because of this powerband loss i always get out of my highest point of power when i shift.

My setup: CAI, Airpump removed. only running alternator,and clutch fan. Stock exhaust.

I have a few questions:
IF you have a s4 n/a rx7, do you have power hinderance at 4k-5k AND a power jump at 5.5k? or is this a special case?

I don't know what to classify this symptom as. power loss midway rpm range anybody have a same situation or clue to why i have no power gain on this range?

 

Wired ports do more harm than good. I have an S5 N/A and the power band is smooth and gradual. I have a little loss of low end torque because of a light flywheel. My power usually plateaus at 7500rpm. But definitly don't wire your ports open. But usually I start feeling it pick up at 4k and it starts going faster and then buries in an instant past 6k rpm.

 

heres a dyno of what appears to be a stock S4 n/a

 

Ouch. I hope the S5's have a little more power than that.

 

good condition S5

 

i dont know bout you but my ride is different. i ha e to have my ports wired open. they are stuck closed. and there isnt much i can do about that. so what else a guy going to do when he's in need of power

 

119 hp that sucks bad. stock only? seesh that's alot less then the 140 stock when orignial.

 

you sure that s5 was in good condition. it didnt look like the vdi turned on, no riase, or even a plateu of torque at about 5300. and why didnt it go to 8k?

 

not sure but thats the highest ive seen for a stock S5 so far

 

dp

 

This is at the wheels, the 140 is at the flywheel. Apples to apples with a bite out of them

 

humm... then it's just about right then. anyone know why a car would want to stop it's power increase durring a rev?

 

my car does not hit the powerband in till 4k and then it just pulls all the way to 8k, only mods is no cat's and a zoom-zoom sticker lol, naw but my car makes power from 4k to 8k, i never feel the ports open up at 35k all ways at 4k. my friend has a t2 and i just take him off the line and he caches up to me, but we stay even, and about in 4th gear i just pull on him, all so if i let him start first i all ways start caching up to him in 3rd gear. i have an s/4 n/a and my friend an s4 t2, he has no mods. yeah cars are kinda crazy lol, hes car works really good, if i drive i can smole a gsr of the line and same with in is300 i take them off the line with his car and just pull on them, but i never feel the boost. my friends stock 300zx i can feel the boost feels GOOD. same with my dads mk3 old turbo supra , i can feel it. well do u feel the boost in a stock s/4 t2? i mean i feel it but not like that was ok , just like a lil pull, and thats all

 

huh?

 

s5 with header and cone intake.

 

S5 with ONLY partial exhaust upgrades (partial headers/NA downpipe, stock exhaust collector, 1 main aftermarket highflow cat, stock catback.)

From that previous dyno graph, looks like full headers & cone intake would add another ~6 ft-bls and ~10HP.

I think a FULL racing beat exhaust and a FULL Mariah Motorsports cold air intake kit (cold airbox/cone intake/stamped headlight cover) should add another 10hp and mabey a bit more torque.