E46CT

the BMW 328i runs about the same max boost. It puts down more HP though. I have a feeling the BMW boost is just tuned stronger. It comes on earlier and stays on longer than the 200t. I think this was likely deliberate on the part of Lexus so they don't destroy their own IS350.
Looking at the stock dyno of the IS200t, the torque peaks very quickly at one particular spot then tapers off. The BMW stays on long and strong the whole way.

zcon

the previous post says the bmw is running 8 psi, at that lower boost level there is more room to grow i would imagine.

E46CT

yup. the tune on the 320i puts it on 328i levels. its the same engine except the pistons are different. 328i can ultimately handle more boost

TSJeff

BMW tunes their engines quite well but as I learned the hard way, you pay the price in terms of reliability. My N54 turbo failed at just over 60,000miles and ended up costing me an arm and a leg to fix.

E46CT

yeah results may vary. depends on how hard you push it with your tune. Theres some people with well over 150,000 miles tuned N54s. and some peoples turbos fail even stock. Depends.

MasonGrey

iTrader: (2)

I'm surprised we aren't at the 241/258 wHP/wTQ at 17 pounds. I definitely agree that the flat torque curve would be very advantageous. I wish that we could just remove the ridiculous delay on throttle input; I almost just got into an accident because I couldn't accelerate out of the way instantly.

MasonGrey

iTrader: (2)

I agree that more power is never bad, but I wouldn't say we're all after 350 levels of power. I purposely chose the 200t over the 350 because I wanted a forced induction car after a series of naturally aspirated cars and a car I could drive aggressively and not get into too much trouble. The biggest (and possibly only) issue I have is that the throttle delay is unnecessary and possibly dangerous.

Pacific13

Fully agree with MansonGrey, in fact for the 200T engine (I own a RC200T) the main problem remain the time-lag with the throttle and with the gear in manual /sport position. Few HP more would be significant due to the weight of the car but with the actual linear curve of torque I think it is enough for a normal (and safely) driving. I owned a Lexus for drinving in silently and comfort and 245 Hp on limited speed motorway (in France 130km/h..) It is great !!

E46CT

Why do you quote the #s as wHP/wTQ? Lexus #s aren't at the wheels. Like every car from the dawn of time, the #s are at the crank.

We do make the #s claimed by Lexus. It goes a lot deeper than that to understand whats going on though. Those are peak #s. How a car manages its power (tuning) is a totally different thing.

Anyway.. unrelated.. I've done something interesting to my car this weekend that opened up some response and removed some of the delay. I'll post about it in a couple days =D I'm waiting on one more thing.

MasonGrey

iTrader: (2)

I understand that it's at the crank, but 17 pounds is a lot of boost; to only arrive at 220 wHP is a bit underwhelming. I am curious to see what you've done because after my experience, I would do anything to remove this horrid throttle delay.

EXE46

You're right on point, I could have afforded the 350 but felt the 200t had more than enough power for daily commute and also because it's a lease. If i was planning on owning the car, i would have chosen the 350.
I have never had a turbo car before and was eager to experience the technology. I am not a slow driver either. So many people want the highest hp and lack the skills to manage those cars. This is something i see everyday in Miami. The biggest issue with the 200t is the throttle delay and hopefully Lexus can fix this with a software update.

E46CT

yeah well it's important to remember that whatever #s you see are *PEAK* #s. And remember stock is 203 whp, not 220. 220 is WITH the tune =) And it's on 93 octane. So our cars in California probably get 5-8 whp less... maybe 195 whp. =)

I agree though we should make more power but like I said these #s are dynamic. we don't make 17psi everywhere and we don't get 200 whp everywhere. PEAK #s. the average # is a lot lower throughout the powerband. The peak hp and peak tq #s you see from lexus only happen for a brief period. So this is why a tune can make a GOOD difference on our cars--peak #s dont tell the whole story!

E46CT

This is a general over simplification, but still interesting. I compared dynos done on the same machine for the IS200t and BMW 328i. Just for fun/comparison. not scientific.

But on AVERAGE throughout the rev range from 2,500 rpm through redline, the cars make STOCK:

IS200t:
160whp
202tq

328i:
207whp
248wtq

Again, not max #s. But the #s to the wheels averaged out from 2,500 rpm to redline. It appears this is a good reason the BMW is faster. It puts down more power and especially torque longer. Its average #s are much higher.

With the alpha tune from BMS the IS200t is helped a bit:

181whp
224wtq

(again, averaged) still down about 25/25. So hopefully when and IF a BMS tune comes out, it will improve on those #s.

I also believe the BMW is slightly lighter than a slightly shorter rear end (I gotta double check that)

Again this is all just for fun in comparing the two cars =)

Sheddy

Don't waste your money on the stage 1. I had it installed on my IS200t and it didn't make much of a difference since it uses a slower processor. I upgraded to the Ultimate and definitely started to feel a bit more responsiveness from the motor ,so did the current owner of that Racechip. I am still running the VRtuned piggyback and it still feels very strong. I am hoping to get it at the dyno once I resolve the boost fluctuations issue.

E46CT

Interesting. Feel free to post as much info as you can. Extremely curious! How do you plan to resolve the boost flutter? any idea whats causing it? I wonder if this is what BMS is encountering?

Also when you are at full boost, what does the PSI gauge show/look like? Does it "Redline?" Would LOVE a video. PLEASE. As much detailed info as possible would be appreciated!