garnet92

At the risk of opening up (again) the debate over how much increase you can expect with these minimal mods, I’ve gotta weigh in with the results we saw at last Saturday’s meet at Powerhouse Racing’s dyno facility in Fort Worth. And, keep in mind that the temperature at midday was about 95 degrees (or higher).

A beautifully kept stock GS400 pulled 231 RWH. While this is at the low end of what we’ve come to expect from a stock GS4, there was no apparent reason except that GS’s, like people, are different - “your results may vary”.

My GS4 with SRT intake/“race” ecu, insulated WeaponR CAB, Torquemaster plugs, and L-Tuned exhaust pulled 268 RWH. That equates to about 334 HP at the crank (using a 20% drive-train loss factor), or about 34 more horsepower than the stock Lexus numbers.

So, you can take this any way you choose – some will still scoff at the improvements. For me, I’d rather have the additional 34 HP than complain about how much those 34 HP cost. The only other mods available to us are NOS (not for me) or SRT’s supercharger (expensive). Maybe the turbo will be available as a “kit”, but it’s more likely to be a custom install at SRT’s facility – at least, for some time.

And finally, the insulated cold air box on the SRT intake and LT exhaust sounded sooooo good at WOT, that I wished that I had a recording. I got to hear the car (from the outside) as others would hear it. It simply sounded so good that several guys commented on how great the “growl” sounded. Maybe I can put up with the drone after all.

For what it’s worth.

RacingAristo

garnet,

Thank you for your information.

fever

Allow me to weigh in on my dyno. I am running close to garnet's setup. SRT intake/race ecu, Borla exhaust, torquemaster plugs.

239.7 rwhp and 271 lbs of torque
Sounds odd, huh? Well, frankly, I don't think the latter number is accurate. I think it was a spike and the more true number would be around 240-250 where it settled.
They took off my filter and bagged another 4.3 rwhp.
I have an email in to Mo about why my gains are so low. I have my layman's thoughts but we shall see. The tech guy said he thought my piggyback ecu was off.
I'll leave you with this: if I can't get this hp issue resolved (260-275) is more like it then I will save my pennies for forced induction or a new car down the road. Frankly I am a bit disenchanted right now unless and until I can resolve this hp shortfall.

DaveGS4

iTrader: (2)

My performance setup is almost identical to Fever's. Last dyno at SRT (before TM plugs) on a hot/humid day with no blower on the car - had issues with heat soak:

With torque converter locked down:
248 rwhp, 266 ft lbs torque

With torque converter unlocked, 304 ft lbs torque


Fever - not sure how many times you've had your car dynoed, but my observation is that the technique and knowledge of the person doing the dyno makes a big difference (based on my whopping two dyno observation). Mo's dyno technique tends towards the conservative method IMO. Other place had no idea how to lock down the TC which leads to the kind of spike you observed.

garnet92

Fever - I don't think that we compared torque numbers, but you beat me on the torque?? Of the two pulls, my best torque figure was 266.7. I had the thought that the temperature might have played a part in the difference - I was first up and it probably wasn't 90 degrees - you were in the afternoon when it was hotter. I pm'd Dusty and Mean Gene to ask what they thought and both agreed that the temp had little effect - but, Gene said that he had recieved a "bad" ecu from SRT and had to have it replaced. Did you get any thoughts from MO?

fever

I emailed Mo but he hasn't replied. I will call him today. This will be the third replacement for the Race ecu. There is no way in hell that I could be putting down 20+ less hp than you with our similar setups if my Race ecu was working properly.
Of course, I'm a layman and could be wrong but what gives here??

SC300T

I'm not sure why most people don't just by an Apexi S-AFC and tune on the dyno instead of buying MO's Race ECU? Seems like you guys are always laying down cash for a proprietary peice that does the same thing that a universal device with open architecture could manage.

Also, If we're at 265rwhp best case on a GS400, wouldn't we be at 285rwhp on a GS430? Back when Lexus changed to the 4.3, they didn't advertise more hp because *I think* the dyno numbers on their 4.0 Liter engine were not where they wanted them to be. 225-230rwhp (4.0) vs 245-250rwhp (4.3).

fever

Well, SC300T, you're probably right. But, hey, I'm not a great student of mechanics, a gearhead I am not. I'm always learning more but had I known a little bit more or talked to someone that could have guided me then I would have had another option.
I talked to Mo and he is sending me a new filter (yea, I could have cleaned it but I am removing all user error variables) and new Race ECU. We shall see...
Garnet92, can you believe the torque of 271? Again, I don't, I think it was a spike that is not indicitive of the truth.

MikeGS4PE

[QUOTE]Originally posted by garnet92

My GS4 with SRT intake/“race” ecu, insulated WeaponR CAB, Torquemaster plugs, and L-Tuned exhaust pulled 268 RWH. That equates to about 334 HP at the crank (using a 20% drive-train loss factor), or about 34 more horsepower than the stock Lexus numbers.

So, you can take this any way you choose – some will still scoff at the improvements. For me, I’d rather have the additional 34 HP than complain about how much those 34 HP cost. The only other mods available to us are NOS (not for me) or SRT’s supercharger (expensive). Maybe the turbo will be available as a “kit”, but it’s more likely to be a custom install at SRT’s facility – at least, for some time.
[QUOTE]


268 RWH with a 20% loss would yield 321.6 HP to the crank. Meaning, only a 21.6 HP gain.

fever

Yea, but you won't find a stock GS400 with 240 rwhp. So, it's more than 21.6.

[QUOTE]Originally posted by MikeGS4PE
[QUOTE]Originally posted by garnet92

My GS4 with SRT intake/?race? ecu, insulated WeaponR CAB, Torquemaster plugs, and L-Tuned exhaust pulled 268 RWH. That equates to about 334 HP at the crank (using a 20% drive-train loss factor), or about 34 more horsepower than the stock Lexus numbers.

So, you can take this any way you choose ? some will still scoff at the improvements. For me, I?d rather have the additional 34 HP than complain about how much those 34 HP cost. The only other mods available to us are NOS (not for me) or SRT?s supercharger (expensive). Maybe the turbo will be available as a ?kit?, but it?s more likely to be a custom install at SRT?s facility ? at least, for some time.

Quote:

268 RWH with a 20% loss would yield 321.6 HP to the crank. Meaning, only a 21.6 HP gain.

garnet92

SC300T – Actually, it’s pretty simple – we all were under the assumption that $525 (when I bought mine) complete with a “tuned” ecu would be all we’d ever need. And that’s comparing to $419 for the S-AFC plus another (quoted) $350 for dyno tuning. We thought we’d save some bucks. And we’d be spending $769 to tune the stock intake? Ought to add some intake as well. So, that’s my logic (or lack thereof) at least. So far, the only thing that’s provided a decent bang for buck is the “race” ecu for $100.

Mike, you’re taking the 20% loss on the RWH number not the flywheel number. The loss is between the flywheel and the rear wheels.

I’ve gone WAY back to the really big thread in March discussing dyno numbers and looked at all dyno quoted numbers in between. This is what I found – there were ten base (stock) dyno numbers quoted. The lowest was 221 and the highest was 239. I threw out a couple that were “suspect” – not individuals that had any history of being accurate. The other numbers were from members that had some credibility. They averaged 233 RWH. So, using the 80% efficiency factor against the quoted 300 HP, we should have seen 240. I think that’s why we were thinking that a stock GS4 ought to pull 240.

There were also driveline losses quoted from 21% to 23%. I believe that it was Mo (SRT) who thinks that the 23% is most accurate. From the average RWH numbers, looks like somewhere around 22% is close to accurate – assuming the Lexus 300 flywheel rating is accurate. Losing 22% of 300HP yields 234 RWH.

There were 7 posts quoting SRT intake/exhaust combinations and they averaged 249 RWH. Lowest was 246, highest was 255.

So … I’ve gotta think that the numbers that produced by my 2 runs at Powerhouse are an aberration and can’t be right. Make no mistake – I didn’t make up the 267.8 number, it was given me by the Powerhouse guys and printed on the chart – 2nd pull showed 265.5. But, I can’t believe them any more. Sure, my particular car could be a little stronger than another, but not that much. So … for my own satisfaction, I’m gonna make an appointment at Dallas Mustang in the next week or two and let them Dynojet the car again. We’ll see what that produces.

All of this (and the March discussion that went to MANY pages) just proves that there really aren’t ANY quoted numbers that I’d stake my life on, even the revered dyno. Last week, a bunch of us dyno’d on the same machine, run by the same guys and got a major difference in results?

Is there nothing that we can believe in anymore? I guess we can't even believe that Anna Nicole's ***** are real?