Brentis

Been doing some reading on the site on what my 6000+ boost delay could be from. I haven't felt comfortable with my prognosis so I want to ask a question specific to my car.

The specifics:

1994 rx7 w/ 19000 miles
mods include: k&n drop, cat back, dp, and boost gauge.

I've just changed the plugs & wires and have significantly improved smoothness, but I can't say the 6000+ response is what it should be.

My boost does the 10-8-10 but once after 6k I get around 6-8 psi. I've seen some folks say 8psi at that range is normal, but the 6psi just feels "pokey".

I suppose it could be the CRV, fuel pump, or a clogged main. So what do you, the experts, suggest? I just bought the car, so I don't know any more.

Thanks for the help guys.

SiKoPaThX

iTrader: (2)

Chek on the things you suppose for starters...

Brentis

That is helpful.

FD Racer

If anything, you're lucky you are only boosting that much. Since you apear to still be runing a stock ecu, I would recomend against boosting much more than that (8psi) anyways (considering your current mods).

Edit: stay below 10psi without one, is all I'm really saying.

turbojeff

iTrader: (30)

Boost at redline seems to be inconsistant. I've had a few FDs, stock and modded like yours with DP, CB and Efini y-pipe. Boost to redline is somewhere around 6-8psi range, depends on the car. I don't think it is always the same car to car.

Describe this 6000+ rpm boost delay? Are you saying the power DRAMATICALLY falls off after 6000rpm or just tapers off towards redline?

Jeff

j9fd3s

iTrader: (3)

jeff is right, its supposed to taper off near redline.

mike

rx4ur7

the boost should stay closer to ten than that.Check all the clamps onyour boost hoses(turbo to IC & IC to elbow)as well as visually check these hoses for excessive conditions.If this doesnt fix it make sure the vacuum chamber is holding pressure,do this by pulling either hose immediately after a "boosted ride" ,it'll either relieve the pressure and youll hear it (this is good) or make no noise at all.(this is bad and you need to check all vacuum hoses).if all checks out and it still has this problem it is most likely the cat

reza

the wastegate spring is at 7 psi.
So I think after 5.5Krpm, the wastegate open fully by stock ECU defaults, because the ECU is not fast enough probably to control the wastegate thus controlling the boost. Remember the only thing controlling the boost after 4500rpm is the wastegate.
Thus say you get 7psi. but you got a crappy boost gauge, or you are not at sea level, you will NOT read 7psi at the boost gauge...

Things to think about...
What is your elevation by the way?

Reza

PS: Oh yea, get boost controller..that should help to modulate the wastegate to close again, keeping the boost at 10psi...
Home Depot boost can't do this...

cartervs

The very 1st replacement installed on my car was the fuel filter.....Ummmm..... Carter

Brentis

Thanks for the wisdom. From what I see the general conscensous is the car does pull some boost off naturally but 6psi at redline may be low.

Changing the fuel filter is probably a wise choice and a boost controller should be in my future (should I get a PFC or just something like a AVC-r?).

Lastly, the cat may be clogged, can one make a road trip or something to burn off the "congestion"?

Reza - I am in Dallas which isn't too terribly high and my boost gauge is a PFS. (autometer?)

Thanks again profs.