Celica Forums General Discussion Engine and Performance Flat spots

hey guys. after fitting a custom sri on my car im getting a few flat spots in lower revs . its really pissin me off. any1 know why this is happening or had it happen in the past. Im contemplating taking it off and just buyin aem or injen.

u mean when its down to like 1500 and you get the bogging (sounds liek it struggling)? happens to me when starting off the line so i jsut rev higher. Common with allot of SRIs and CAIs. some peopel get it some dont. TRP is only one that prettymuch eliminates it.

Yeah you lose power down low with the short ram. You will get bogging with a cai too when its hot out. Like hombre said, get the tpr intake if its that bad.

There is another option; the "Blue Bomber Mod":

The BlueBomber mod is basically cutting the MAF housing tube out of the stock air box and using it in place of the MAF housing of an aftermarket intake.

The reason for doing this is Celica's MAF and ECU are calibrated to detect and calculate air flow thru a 2.5 inch opening with fins just in front of the MAF to minimize air turbulence (stock air box). Notice the fins are straight and not angled in any way. This is done to ensure that the air passes through the reeds of the actual maf sensor at a straight angle with a minimum of turbulence.

Most aftermarket intakes both cai and sri (AEM, Injen, K&N etc etc.) place the MAF in a 2.75 inch finless tube environment; this can sometimes

throw off the readings the MAF sends to the ECU, which can sometimes lead to the ECU miscalculating how much fuel to inject into the cylinder and cause Bogging or a Check Engine Light to come on because the mixture is too lean or too rich.

Not everyone who uses an AEM or Injen intake will get CELs or bogging.

The TPR CAI and intakes with the BlueBomber MOD dont Bog and throw CELs because they have the correct MAF environment dimensions and fins to minimize turbulence near the MAF, which helps to ensure the ECU always gets the correct air flow reading from the MAF.

You can find an install guide for this mod over at new celica dot org.

> INSTALL > Engine / Performance > INSTALL: PERFECT CAI (Hybrid Aftermarket Intake/Stock Airbox Mod)

The TPR intake is the only intake that I know of to use the same MAF dimensions as the stock air box, unfortunately there is a long waiting list to get them.

Its called the Blue Bomber mod because he invented it, and actually did it; props to him for doing so.

thanks guys,
great info. yeah ive been in other celicas that bog slightly but this is worse in my case. i'll check out tpr. once again thanks

Just my 2 cents, and for what its worth.

I attribute this variation to a myriad of tolerances and slightly out of spec parts that exist in any mass produced machines, especially in something as complex as a modern day car;

The fact that there are nearly infinite combinations of parts that are at the edges of their tolerances; electrical and mechanical alike. Some examples might include the diameter of a fuel injector port, the quality of resistors and semiconductors from one lot to the next, and the what some would consider esoteric elements like barometric pressure air temp, humidity, etc.

I feel the degree to which the MAF readings are thrown out or off is just at the edge of the stock ECUs ability to compensate and adjust for, combine that with the individual characteristics of our cars and all the environmental factors our cars operate in; thus is my theory why some people get bogs and cels and some dont.

One more thing to consider:

http://monkeywrenchracing.com/mwr_celica_gts.html

Apexi Power FC - Toyota Celica GTS

"Well, after some long nights and lots of tuning, we're done with our first serious Power FC program for our 2000 Celica GTS.

Results are great, more than we had hoped for. The car was tuned originally with the Power FC and no other mods. It made good gains, but the stock ECU isn't horrible so we chose to wait until the next step to release any results. The Injen CAI is notorous for it's poor drivability and midrange torque when used with the stock ECU- it doesn't emulate the stock air intake tract very well at low airflow levels. That is not a problem with a programmable ECU.

Results:

Stock Celi GTS with Injen CAI made 167 whp and 114 wtq. Not bad, 167 is about average for a GTS with an Injen. We could tell the car was not running at 100%. Time for the PFC.

With only the addition of the tuned Power FC, power jumped to 177 whp and 123 wtq. Excellent gains considering the nearly stock car, but there's more to the story:

1. The Injen and stock ECU combination drives very poorly at low RPMs. The PFC drives great, better than completely stock in my opinion. I can now lug the engine in traffic and find I need to downshift much less often."