Although the GS400 is rated 300HP, not all the power is delivered to the rear wheels on the dyno. I think the manual tranmission has higher efficiency than the auto transmission.

I don't know why y2kgs did not feel the improvement from the SRT intake, unless he does not install the ECU. For me, I could feel the power gain immediately, and especially at high speed, the power is immediate and gratifying. Anyway, I would like to hear how much HP gain you get from just the Weapon R intake alone.

 

I hope to see the dyno results soon.

 

247ft/lbs of torque. The operator at mti had a black 98 and he said his was 234hp.

 

gs400tx,

I assume your 234 rwhp is for stock GS400?

 

At the wheels HP = CRANK * 75-80% (roughly). So 300 * 75-80% = 230-240 HP at the wheels. The "roughly" depends on each car's drive hardware (tranny, transfer case, differential, wheels, etc.).

 

By wheels do you mean wheel size? How does the wheel size impact HP?

 

if you have a large wheel and larger tire (larger overall diameter) it acts as a taller gear, you will hit redline in each gear at a higher speed (even though it will say its the same speed on your speedometer) because one rotation of the bigger wheels covers more length that a smaller diameter wheel/tire would. this slows your car down because it has to accelerate more per gear and doesn't have the power to do so. Also most bigger wheels are heavier than stock so that add weight that the engine has to push before any of the power gets down to the ground.

 

You would be right, in that larger wheels / tires would slow the car down, however, when you exchange your 16 or 17" rims for 19 or 20" rims, the tire thins out. Meaning, it's lower-profile. So, after you're done upgrading, the diameter of the whole wheel/rubber combination is almost identical to that of the original 16" set. Therefore, you wouldn't lose any acceleration. However, that would be the case if the new wheels were the same weight as the old ones. But, they're usually not. So, different wheels affect final HP output, but not by the diameter. They do so by weight. Larger wheels = heavier = less HP (since there is more hardware to move). Remember, that the HP of the engine is unaffected. Only the DINO would show you less HP. The car would feel slower too..

 

That makes sense. Thanks!

 

HLEE:
y2kgs surely installed the whole package just like you did. The power gain is nowhere close to be satisfying. HE is doing this new combo to improve all of our cars, quite frankly i think we should all be greatful and stay tuned for the result, which is today. wednesday.

the Weapon R itself is a bigger intake which sucks in more air, compared to SRT. The intake itself with cold air ram has performed around 15 hp at the wheels already on a IS300. think about how much it would gain on a GS4?

 

yep right down to the 17s.

The mti guy said he pulled the exhaust system right behind the cats and ran his again and it got ZERO additional hp.

 

gsintensive,

I certainly appreciate that y2kgs is doing us a service by testing a different intake. Like him, I am hungry for more power. But from reading his post I am a bit confused. Maybe y2kgs can answer this, are you using the Weapon R intake with SRT's ECU, or are you running with the Apexi? I thought that SRT's intake works better than RMM is because SRT has the ECU to inject more fuel for the larger air volume now. Without the compensation, doesn't the mid-range power usually drops? Anyway, I eagerly awaits the dyno result of the Weapon R Intake.

 

from what my understanding,
y2kgs will do the dyno
(Swift intake wECU) v.s. (Weapon R intake and Apexi S-AFC)
correct me if i am wrong y2kgs? There is no point doing Weapon R with Swift ECU, you can't get the ECU alone anyway.

The Swift ECU modify the signal to the car ECU (I think the map signal) to effectively fool the ECU to pump more gas or less gas. You are not physicly changing anything, everything will still be within the factory specs (injectors and fuel pump rate limitation)

Apexi pretty much does the same thing, the only thing different is the Apexi setting is adjustable, so you can effective enrich or lean out your mixture at the tip of your finger while you driving hee hee

on my other car, i lean out the mixture alittle bit on long distance driving to reduce the gas consumption. or enrich the mixture alittle bit
:eek:

the only exact way to get every HP out of the apexi unit is to tune it on the dyno jet.

I hope y2kgs would post some settings that he uses so I can use them as a starting point for mine setting when i get the unit.

"Without the compensation, doesn't the mid-range power usually drops"
NOT truth, prove me wrong, but every single car dyno i've seen with a high flow intake (with heat sheild or cold air setup) (no ECU change) shown some kind of gain in mid and high end.

hee hee

Anh

 

Well, here is all the numbers as of yestherday. Sorry the chip that Weapon R is using isn't the APEXI but one that was made in Japan. My car is almost done with tuning but we are going to do one more run later on. We ran out of time given that my career isn't in the auto biz. Don't worry cause we might all have time to finish next week

These numbers are for a GS400 with 18's 275/245
Stock GS 236HP
SRT GS 249HP
Weapon R w/tunable chip 258HP but not done yet

Note that I was using a Stage II from Weapon R to run the test. Everything looks good right now so I will let you know more by next week. That is if we all have time

 

wow, 22 extra hp at the wheel is really good for an intake. can you explain what does that "tunable chip" do? what can you tune exactly? also how much is this stage 2 setup?

thanks for doing these test! i'm sure everyone here really appreciates it!!!