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Discussion Starter #1 (Edited)
Hello,

i did install a set of DT long tube headers + DT Y pipe & TRD cat back on my FJ 2008. I can't notice any increase in the power since i tested my car with my friend who is having a stock FJ 2009 and his car was 2 meters a head :(

Why is that ??

i only notice that the engine is relaxed and the RPM is always low even on the high way on 140 speed the RPM on 2.3

Do i need throttel response device ??

note that i will install VOLANT Air Intake soon. " will this fix the problem or i will need a UniChip "

please advice
 

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You have decreased the amount of back pressure created by the exhaust, thus reducing HP. I would recommend removing the DT long tube headers.
 

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Exactly what kind of performance gains were you expecting to get?

KyFJGuy
 

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I would not get a volant intake the diameter of the intake tube is small and has caused maf problems on other 1gr's. The only intake I would recommend is a the AFE stage 2 or a 1st gen TRD if you could find one. I would also look into tuning as you straight piped it using a stock tune. If anything for now throw on the factory y and wait until you get something to tune your truck with.
 

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Discussion Starter #6
You have decreased the amount of back pressure created by the exhaust, thus reducing HP. I would recommend removing the DT long tube headers.

i can't remove the headers since i spent money buyit it , is there any alternative soluation ??
 

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Discussion Starter #7
Headers only give you more hp at high rpm; you will lose torque (and hence hp) at low to moderate rpm, where 99.7% of all people use their engine.
what do you recomend ?

i am thinking to a get a UniChip & AirIntake next month ?
 

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Discussion Starter #9
No; what you did has altered the power band of your engine (as intended by the design of the headers).
my friend told me when i will install the airintake i will notice the differences and with the unichip programmed to handle all what did i installed earlier ( headers + airintake + catback ) it will be fine ?? dont you think so ?
 

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Discussion Starter #10
So,, what is the recipe of having a nice performance ??

airintake + catback ?

airintake + catback + unchip ?

or what ??

please advise me guyz i am new in such stuff ?

not that i live in a place most of the time the weather is hot, i live in the United Arab Emirates
 

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my friend told me when i will install the airintake i will notice the differences and with the unichip programmed to handle all what did i installed earlier ( headers + airintake + catback ) it will be fine ?? dont you think so ?
No. I have run headers on lots of my engines over the years, and many more installed on customers motors. Every header I have ever seen is designed to produce more horsepower at wide-open throttle*, because that is where the big hp numbers are and big hp numbers are what sells headers. That is why I would never put headers on a modern 4WD truck, because they need torque low in the power band not high where you will never use it. Everything in a 4-stroke gasoline engine is a compromise; you can't have it all. You have to choose (with cam timing, valve size, and exhaust design) where in the rpm range you want your peak torque and power band. By installing headers, you just moved yours way up in rpm. You can spend as much more money on further mods as you want, but the bottom line is that the headers moved your power band.


* The few exceptions (I have seen) are tuned headers designed specifically for F-engine Land Cruisers, and tuned headers designed for use with certain cams in Harley v-twins, both of which are low-revving motors that make their torque way down low.
 

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No; what you did has altered the power band of your engine (as intended by the design of the headers).
X2! The headers are the primary problem...

cheers,

dale
 

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So,, what is the recipe of having a nice performance ??

airintake + catback ?

airintake + catback + unchip ?

or what ??

please advise me guyz i am new in such stuff ?
No offense, but you need to decide what you want to do with your truck, how you're going to drive it, before you start throwing money at it and making modifications that you have no idea how they will affect it. A little homework before you started building a motor would have saved you a little grief and a lot of money.

So let's start back at the beginning: how will you primarily use your truck? Dune racing, around town, highway, drag racing, rock crawling, mudding, or what?
 

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I have some sweet Type-R decals that might solve your problem.
 

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Halla AlBadi,

As everyone said the problem is the headers.

If you want maximum power:

- keep the y-pipe and the TRD cat-back

- add either the first generation TRD CAI or the AFE stage 2

- go to AlQusais to the unichip shop and tell them you want the q+ unichip + the throttle booster

If you do all of this I can guarantee you will have a very powerful FJ!!!

If money is not a problem, then I would go with the TRD supercharger :clap:

Good luck bro
 

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This is the dyno chart of the long tubes. As you can see the power increase is just like 1911 said, all in the top end and at WOT, that is how these long tubes work. With your current setup its very good for FI engines. Now like others have asked what are you using your truck for? The tuning will help slightly but you'll still only see gains at the high end of the rev range. You could switch to shortie headers if that is what you want but without more info thats the best we can do.
 

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AlBadi
I would almost think most of your offroad driving would be at higher RPM's, and this may not be a problem at all. When I was in UAE, we went out to the dunes in Land Cruisers. Because of the soft sand, our motors were at much higher RPM's than what they would be for the same terrain on hard pack or rock. Also, you don't have trees to worry about hitting, so you are usually able to travel faster through this terrain which also raises your RPM's. Plus, your highways are a lot like the autobahns here in Germany, and my RPM's are quite high just going the speed limit (130km/h).
 

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Discussion Starter #20
No offense, but you need to decide what you want to do with your truck, how you're going to drive it, before you start throwing money at it and making modifications that you have no idea how they will affect it. A little homework before you started building a motor would have saved you a little grief and a lot of money.

So let's start back at the beginning: how will you primarily use your truck? Dune racing, around town, highway, drag racing, rock crawling, mudding, or what?
Basicly i am using my truck for the following:
Dune racing
Around town
Highway
 
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