Too much boost?
 

Today after i corrected my timing on my 87TII i took it out and it ran alot smoother. What i'm concerned about is the high level of boost i get. The engine was rebuilt about 8,000 miles ago by pineapple along with the turbo i beleive (previous owner with receipts). I upgraded the exhaust and gutted the cat. Thats the only performance that's been done to it. It idles rough and about 1-200 rpm lower than suppose to (bac doesn't work so good). It also won't idle when cold - not a big deal- and emissions are still on. When i open it up i can peg my boost guage (stock). I also experience the 3880rpm but i associate that with the boost level. Is it common to run that much boost from just open'n the exhaust. I'm just don't want to ping. What is a good size for injectors if i want to upgrade to something a little larger and be a little more safe with this boost level.

thanks

first thing buy a real boost gauge...

if you're not hitting fuel cut it's probably not running too much. (you don't have an FCD do you?)

but yes removing the cats and adding an exhaust will almost double the boost. from 5 to 10psi.

Re: Too much boost?
 

Get an aftermarket boost gauge for one. We have no idea how much boost you are getting.

Keep out of WOT when the engine is cold.

3800 rpm stumble: clean your existing grounds, and put dielectric grease on the metyal contacts. Re-gruund the engine, ECU, exhaust, and battery with some decently gauged wire. Add some GOOD fuel system cleaner (such as TKO).

Injector upgrades need fuel control. First you need to fix the car, then upgrade.

What you should be doing first and foremost: get a boost gauge.
Then:
EGT/AFR gauge.
Port your wastegate.
Fix the idle. You don;t need the BAC to have a good idle. Check for vacuum leaks.


Yes, boost will rise with open exhaust.

And write more organised posts... it makes it easier to write an organised response.

You don't mention wether you're hitting fuel cut, which you should be, unless the previous owner installed a Fuel Cut Defenser. If you are hiiting fuel cut, do NOT boost that high, otherwise you will be going back to Pineapple with a blown engine, and they will tell you you're out of luck. You also should check to see how big your injectors are. If they are standard, then you should install 720cc for the secondary injectors.
You might also want to install an aftermarket boost guage as the factory one , is 'iffy' at best.

Well the deal is it never had the 3800 rpm hesitation before the exhust. So that pretty much tells me it fuel cut.

I don't run wot b/c i knew what was going on with the fuel cut.

fuel<<air=ping

i plan on fixing the other quirks when i get time. I had to replace the exhaust b/c it was broken.

Beside the idle and boost she runs great.

i was just curious b/c with exhaust and intake on my sr20det it only added like 2-3 psi

On a TII going from factory exhaust to full cat-less exhaust, can give you about 50-60 hp :eek: (depending on exhaust type).

:)

i think the 13b got beat down on by emissions.

I wanted the TII as my dailly driver b/c the sr20 isn't very streetable. I got pulled over twice in 5 min once in that thing has too much power for my weak will :(

one quick question. There is a plug on the BAC (two wires). It's broken and not connected - I think that's why it wont idle well when cold. What does that exactly do? Turn the cold start on?

Per Paul Stoaks - Lots of good idle troubleshooting info. here.