Had a major service today and dyno tune, and took the car in to get my new Fujita F5 SRI (MA2812) installed.

My car lost 10KW (13HP) at the wheels after the stock intake was removed and replaced with the F5 and was running incredibly lean. To top it off it only dyno'd at 168KW (225HP), only mods being Nismo exhaust. Stocks should run at least 230HP, correct? They opted to put the stock intake back on and implied that this is a common problem with some cars and the only way to fix it would be to get a custom chip. I was also under the impression that the *** spec 350GT's had a slightly higher tune (210KW as apposed to the US 208) due to emissions.

So, my question is, should of the SRI been left on for a day or two so that the ECU could re-configure its fuel to air ratio itself? Couldn't of the tuners done that for me?

 

hmmm. thats wierd. after i installed my jwt popcharger i think i felt a difference. it mostly made a sound but i dont think i lost power.


but on a sidenote i have heard that the stock airbox is the best for our cars

 

You paid for a dyno tune yes...then they should have imo, reset your ecu so it could start learning your new intake immediately and adjusted your AFR maps after your pulls.
Isn't that what a dyno tune is all about?

 

i think he just got dynoed. thats it..if you do a search you will find that intakes for our cars dont do **** for performance

 

I took my jwt intake off and gained 5rwhp. DO NOT GET AN INTAKE unless IT is the stillen.

 

I removed my injen and felt a difference. my car makes more torque with the stock airbox on. Heat soak is terrible with aftermarket intakes

 

our stock air box/setup is pretty damn good, the only thing i could see helping is the ''ztube'' which smoothes out the air flow vs. the restrictive stock unit. before i bought my intake i did alot of thinking and comparisons and i concluded that the stillen set up is the best. it blocks a majority of the engine heat when at a stand still and pulls in fresh cool air when the car is in motion. the best imo.

 

Just goin by OP first sentence... 'Had a major service today and dyno tune,...'
I've been contemplating this switch of intakes myself for awhile. The heat shield on the JWT is a joke. Or just do a KN in oem box.

 

stillen has a nice box but all intakes do about the same

 

So, when makers like Fujita etc claim to increase RWHP by 8-10 HP, its a total joke?

I didnt really buy it to get more power, more so just to have a less restrictive intake and for a better induction sound. My biggest problem is that it decreased by 13HP. If it had of stayed the same I wouldnt have been fussed.

The other thing is the car feels quite sluggish and un-responsive. I feel like resetting the ECU myself and just starting afresh.

So, my big question is, is it dangerous/bad to run my engine lean? What if I chuck the new intake back on, let the ECU re-learn the fuel ratio (will it definately re-configure itself?) and then take it back for another dyno in a week or two? Does that sound like a good idea? I can't return the intake and it cost me $250 so I figure I may as well try to get it to work.

 

Most people do not see the gains that most all companies claim. If you don't want more power, just a louder induction sound, then a z-tube/power duct removal would have been much cheaper and better for you.

 

+1 on both my g's i never put an intake just new filters.

 

What type of dyno was this? The heatshield for the JWT popcharger does a pretty good job of keeping the intake cooler imo. Lots of people have posted gains of 5whp with this setup. Stillen's is probably the best though. These are the only ones I have ever heard of that make gains on our cars. Buy anything else and you're wasting money and possibly loosing power.

 

The only difference I can see with the JWT is in the heat shield, which looks pretty crappy, and seems to be made of metal. After a while that thing is gonna get pretty hot and is just going to radiate heat its collected right into the filter. It also seems to block off the front air duct.

Biggest problem I can see is that the MAF or ECU just hasn't taken into account the new intake and hasn't adjusted accordingly. The loss in horsepower and the fact that it was running lean could only really mean that it was sucking in alot of hot air, but this was in a hot workshop with no airflow, I would imagine the results would be quite different when actually driving.

Even if i kept the stock intake and just updated the z tube, im still going to have this problem if the maf or ecu isnt updating, cause theres going to be more air, the maf will be cooler and it will still run lean.