I have gone through a lot of posts..here on the forum boards. I have not seen any actual results comparing the above listed intakes. Yes, there was a comparison with the srt w/o the ecu, and WR, and injen...

I was just wondering if anyone else has dyno'd the srt w/ piggy back, vs the other intakes...

Also, has Anyone had a problem with the piggyback... running lean, hurting your engine, dealer voiding warranty, any problems at all?

We are looking at purchasing a intake, but would welcome all suggestions...comments..feedback...results...etc

 

if you want to retain any at all of the lexus refinement , the srt is not for you .. it is very LOUD especially at WOT.. power gains IMO were minimal at best ,, not worth the trade off for the noise .. i had bought one from dex had it on the car for just under a week and wife complained about the noise so it was taken off..

I did a DIY mod to my airbox by cutting a 2.5 in hole in the plastic piece down next to the foglight and piped some cool denser air up into a 2.5 in hole i cut into the face of the oem box to add more free air flow than just the snorkel will provide..then i put in a toms drop in high flow foam filter..

Guys believe it or not i am getting better throttle response on the low end and about the same mid to high pull as with the srt setup and all this for under $95 including the toms filter from steve ganz at $84



i have had other people ride with me to confirm this with srt and my DIY modded airbox and there is no discernable diff and no noise


goddluck in your decision

 

Hey bro, when you had the SRT on, did you notice any power gains from a stop? Why would anyone do this mod if there is no discernible difference in acceleration from a stop? The GS400 accelerates very hard from 30 Mph anyway, so why would one do the SRT mod to get some gains in that speed range? I still don't understand why this mod is considered important by some folks here........... <shaking head confused>

 

hameed

you are a real smart guy , all i have to say (read between the lines here ) outstanding marketing on behalf srt..

from a dead stop its very bogged down , too much much hot air entering the throttle IMO..hot air ingestion is another problem..the sound , not my or my wifes taste..kinda sounds like a corvette with a loud exaust to me not meant for a lexus even a modded lexus..

try the diy mod instead cheaper and about the same results .. VVTI tech to smart to play with or alter with a simple ecu wire in.. IMO all the ecu does is raise the shift points and alter rpm curve

anyway good to hear from you bro

 

Since the SRT is not CARB certified I would not consider it personally, but... In conjunction with a high stall torque converter the SRT might make sense. With the TC I have tremendous kick off the line -- often too much. So a loss of kick off the bottom end [nullified by the TC] could be considered a good trade for extra oomph at the upper end. As for a stock GS pulling hard beyond 30mph, it does ok for a 4 door sports sedan but I want more.

 

Not sure what you're trying to say here lexforlife, why don't you spell it out for us? SRT has some claims that to me are a bit extreme on their website, but some GSs of members from CL have been dynoed with increases in HP similar. Mine is not one of them but I would not give up my SRT intake / ECU because of it.

You had the SRT intake on for what, a week? That's barely enough time for the ECU to re-learn the changes and in my car it took the better part of a couple of weeks of driving before I was satisified with the power increase when I first put it on. IMO you don't have enough information to give an accurate comparison. .

I personally felt no decrease in power at the low end, but I put it on at the same time as the TC, and those two together make a great difference. The TC for takeoff, the SRT intake for mid/top end.

Again, not quite enough information that can be gained just by reading the forums here in a little more detail... the SRT ECU does nothing to change the shift points and alter the RPM curve. It remaps the air/fule mix to allow for the increase in airflow from the much larger intake pipe. Just try driving (or dynoing) a car with the SRT intake on WITHOUT the ecu and you'll see what I mean.

LFL, not trying to jump on you here, but IMO you're giving out some bad info that needs to be corrected. I'm an SRT product fan, but have never been paid for it or given any sort of sponsorship by them. There are lots of other alternatives to consider as well, the only one I might do were I making the same decision would be the K&N. CARB certification is nice on the K&N, too but doesn't matter if you aren't in California.

Either one will give you a substantial increase in sound volume in the cabin, the SRT is louder. It does take some getting used to, but you'll be addicted to it once you drive with it on for a while (assuming it passes the WAF (wife acceptance factor)).

 

The conclusion I have drawn from your experience and Eric's (SN mumbles) is that the SRT intake causes the GS to lose some of it's low end punch in favour of some high end punch. To me this is completely contrary to why you would want to do this mod...............

If anything the only mod that makes sense for a GS400 is the PI TC which other folks here have done. Now that mod makes perfect sense - it reduces some of the lag that a GS400 has from 0 - 30 mph.

So to summarize:
Positive aspects of the SRT (and perhaps other intakes):
1. Noise? (for some like you lexforlife and me, this is a negative - considering the fact that my car has the L-tuned exhaust and that is noise enough for me)
2. Some increased power on the top end.
3. The looks

Negatives:
1. Noise
2. You lose bottom end power (this is a very BIG negative - in my opinion this negative outweighs all the positives by a very significant margin)
3. Possible problems with the engine due to the piggyback ECU

Conclusion:
Stay away from the SRT intake unless the 'looks' and 'noise' factors are paramount to you .

 

dave

not trying to restart the wars of the intake dilema but some of your info is not quite right.. as far as ecu relearning , it takes a avg of approx 200-500 miles to relearn new info for its a constant relearn process to adapt to new drivers all the time within the week i had it i drove about 600 miles hard ..logics prevail here.. yes there is some remapping of the air fuel ratio but the main ecu will still overide any max attempt to reprogram i say this because all you are connecting is 12v for pwr ground for ground , a wire to the rpm sensor a wire to ign sensor so all in all what really is going on , remapping of air/fuel to max parameters and altering ign and rpm curves to give appearance of more power the vvti tech is to smart even for srt.. again great marketing ...all the previous posts i have read dont quantify the numbers posted by them by a long shot in fact some even said they gained alittle horsepower but lost some trq.. you will lose down low esp when the engine is hot no question about that you dont see it for you have a trq converter..

to make it short , yes there was a small gain , not enough to justify the money spent and the sound it produces.. nothing will give this car more power without either forced induction or reworking the internals , plain and simple wether we want to believe it or not ..

oh by the way if the little hocus pocus black box did what they alledge it does then it should improve low idle problems to some degree for me did nothing at all


dave , no attack here at all but talking from exp trial and error and conversing with shop foreman at dealer who is actually a friend of mine who at my dealer is known as the "gs guru"

 

LFL, if you reverse engineered the SRT ECU programming and wiring in a week you're a smarter man than me . 600 miles in less than one week, driven hard? Wow, but I still say not enough personal experience for such a strong opinion to be offered by you. I guess we can agree to disagree on this point.

I'm sure your friend at the dealer is a GS guru, but that doesn' t necessarily make him an aftermarket guru. ALL of the top Lexus master techs at my dealer had never seen an intake on a GS until I pulled mine into the shop, and they are VERY good GS gurus that I'd trust with anything on my car. But the fact is they know very little about the aftermarket - only what Lexus trains them in.

Do you have before and after dynos of your car with and without the SRT and home-made airbox you can post to prove your points? BTW, here's a good one with dyno numbers on the SRT to read in case you missed it earlier (back to the original purpose of this thread ) -->https://www.clublexus.com/forums/sho...threadid=72625

My thought is that this dyno is the extreme positive end of the spectrum and there are other GS's that don't improve as much. There are MANY other factors to take into account as well like Hameed lists (paramount the WAF as you know because yours didn't like the sound), so getting all the knowledge you can - pros and cons - is the best way to make a decision. IMO it's the intake is a decent investment (maybe 7 on a scale of 10), but I'd do the TC first or at the same time.

 

dave point well made ,, i have not dynoed either (and this might sound funny) but i go by the seat of my pants to determine what works for me .. i have certain roads i travel on everyday and know exactly how my car reacts to temp etc etc.. i know when it was on there was some gain but only mid to high and to me it was minimal.. i mwould use a long part of i75 from one exit to another and basically time myself and also watch how fast i reach speeds i am looking for , again it may sound funny but come on guys , whats really the bottom line how much numbers you can get on a dyno with open hood and fan blowing on it or real world driving situations

me , give me real world any day for thats what counts , winning not numbers

again dave thanks and respect due

 

Keep up the debate...it makes for good reading...at least everyone is civil here.

To a degree, I would side with lexforlife, in that many outside conditions can interfere with real world driving vs. just doing a dyno. We all know how "our" car feels and if we feel any gains...this isn't scientific or reliable, but it provides comfort to the individual and meets their expectations. On the other hand, the point that davegs4 is making is simply that the SRT intake does deliver increases in HP based on factual dyno results. So, both of you are correct in your assessments. They are just differing points...

At the end of the day, everyone should recognize that they should only purchase those items or goods that are respective to their needs or wants. Also, based on the shear number of members that use the SRT intake, I would speculate that the performance it provides equals the expectations of these members.

So, back to the original question by koreanpers...it doesn't seem that anyone has results of specific dyno's utilizing the various competing intakes available for the GS...BTW, you should mention which model you driving because you will get differing results.

 

has anyone tried injen?>

 

I remember way back that CL dedicated a battle of the intakes(SRT, Injen and Weapon R), and I do believe that there was some interesting results as the intakes were independantly dyno'ed.....what ever happened to that?
What was the outcome, who was the winner?

 

Another perspective...

Here's the mods I did (in order) and the effects I experienced:

- Drop in K&N filter - I think the car felt a bit more responsive.
- L-Tuned exhaust - Again, I think the car felt a bit more responsive
- Precision Torque Converter - HOLY CRAP BATMAN, car's a BEAST off the line
- K&N intake kit - seemed to reduce low end response a TINY amount initially, but I think that went away as I put miles on the setup. The TC / intake combo was still MUCH quicker than stock
- teck kit grounding kit - I think the car feels more responsive, as if every day is a day with cool air even when it isn't. Car feels QUICK.

I went for the K&N intake instead of SRT's for three reasons:
1) K&N intake was half the price
2) I trust K&N more than SRT
3) I am not interested in messing with my car's electronics.

A fourth reason I only realized AFTER putting on the K&N intake is that I MUCH prefer its sound to the SRT's. I have no whistling whatsoever, for example - I think the K&N intake sound is lower, a bit more subtle, but still sounds AWESOME.

DaveGS - one point on SRT's "ECU" - I've heard there's no 'programming' in it, that it's just a 'circuit' (e.g., resistor pack) to modify the fuel air curve. I believe the SRT intake pipe is bigger than stock, so my understanding is that without the 'ecu' the MAF (mass air flow sensor) would think the air speed is less than it actually is, so the ecu corrects for this.

Next mod soon: 3.76 Torsen diff. - car's gonna SCOOT even more off the line. My main thing with it though was improving traction in tight turns and reducing how often the VSC interferes.

 

Bit - Not sure where you got that info, but I think there is more than a resistor pack. I've actually watched Mo at SRT push down a new application to the SRT ECU in my GS when I upgraded to the Race ECU logic.

Unless he did this purely for a show (which I doubt) and faked the before/after dyno of my GS which increased after the programming change (and that was the ONLY change that was made) I can't imagine that would be a correct statement.

Can't wait until you put Dex's differential in your GS, should be another TC-like upgrade for you!

The dyno test was never completed correctly and the results were declared flawed. There are some new players in the market today too (K&N) that would be great to see in a retest.