Exhaust Question

Im gunna be running straight through 3 inch exhaust in the next 2 weeks from the down pipe back. I was wondering if this will casue alot of boost creep? if so i need to know so i can buy an aftermarket FCD, so the car dosent bogg out like it did when i had the boost controller on there and running past 9psi. PLEASE LET ME KNOW ASAP!!!

Yes, an open exhausst will cause spiking and creeeping.

Fuel cut is at 12 psi, not 9.

You can completely eliminate FC by corking the vac line to the map sensor. This will also kill your OEM boost gauge.

Hmmm must have a problem there with my boosting then. Becasue when i stomp on it i peak boost at 10 and then it drops to 9?? Do you have instructions on where i can cork the OEM map sensor vac line ?? if so then i can reinstall my boost controller tmw. thanks

Jeff could you find a picture of the MR2 motor and circle what hose to cork?

SpoolingMr2, are you hitting 9 psi of boost or 9 bar?

The map sensor is EASY to locate:
*It is on the firewall between the engine and the trunk.
*It is next to the small grey "diagnostic box"
*It you are on the passenger side of the engine bay,it farther from you than the diagnostic box.
*It is about the same size as the diagnostic box (a little smaller).
*It has one vac line coming from the manifold and one eletrical connector going to it.

Simply cork that vac hose (leave the electrical one connected!) and you have gotten rid of fue lcut completely. The OEM boost gauge will no longer work, but that thing is worthless anyway.

Please know that if you buy the HKS FCD, you can RAISE fuel cut to a higher boost level (17 psi).
Fuel cut is pritection device and you should realize that before you eliminate it.

I have run my MR2 for 3 years with that hose corked with no worries.

9 psi... should i be worried? the car runs fine other then i guess im not getting the right boost amount.

9psi is nothing to worry about, but there is no way you should hit fuel cut at 9 psi.

I wasnt hitting fuel cut at 9psi. I installed my boost controller and turned it up to 15psi without knowing i had a fuel cut at 12psi. I guess you could say it was a test and trial type situation. no i know what i need to do to avoid this from happening. This for the info. on where to find the vac line.

[QUOTE=JekylandHyde]Yes, an open exhausst will cause spiking and creeeping.

My mr2 is completely stock and i want to add an hks hiper exhaust. Would the boost still spike or creep?

Yup...but not as much as to say if you were running just a downpipe.

spikeman, spiking/creeping is only an issue if it is doing it to a dangerous level. With the OEM turbo, you can open up the exhaust all you want (DP and exhaust) and you are not going to surpass 15 psi (if you even get that far) ... so you are in no danger.

The only thing you will most likely do is hit fuel cut at 12 psi.

anyone know if the tko exhaust is loud or not. i'm planning on getting a dual exhaust system, but i don't want a very loud one either. if there are other dual exhaust out there for the mkII, plz let me know. thanks.

Jekyl - if i upgraded to an external wastegate, would that also solve my problem?

What turbo are you on?

An external wastegate will offer more control and help boost creep/spike if it is set up properly.

I'm using the stock turbo for now.
My plan was to go with the ATS TD06, which comes with an external wastegate setup. If i did that, and got a free flowing exhaust, would i have to worry about the td06 spiking? Obviously i would have an fcd, boost controller, intercooler, etc.

Also jekyl would i need to buy a greddy bcc or does the boost controller already do that same function

The External Wastegate on the TDO6 is a great idea ... Aaron and ATS will take great care of you.

If you run more than 12 psi of boost you need to resolve Fuel cut.

You can:
*cork the vac line to the MAP sensor for FREE. This eliminates FC and disables the worhtless OEM boost guage.
*buy an HKS FCD which rasies FC to 17 psi ... so you still have the FC protection
*buy the GReddy BCC which eliminates FC and waste money since you could have done the first item above :)