Quote:
Originally Posted by PoorMans180SX
I can see what you're saying from a budget perspective. However, I still disagree with you on your "less than 400whp is pointless". Have you ever driven a two liter with a new tech turbo at 300+whp? It basically feels like a small block V8. It presents it's own challenges to be sure, but boy does it make it fun. I'm sorry but your 50 trim plan will never do that. Taking until 5000rpm to make over 300lb-ft just isn't impressive.
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50trim T3 style turbo can be as fast as newer turbo. You can't go by torque because cam phase, tuning, the entire setup will mediate torque and at low flow rates, none of those turbos will be blowing hot air yet (sub 5k is same temp air for the most part) so there is almost no difference for low rpm performance between them. My graphs are almost 20 years old and that plays a role in what I was doing back then. Also keep in mind 350hp at 4000rpm is 450lb-ft of torque, so any turbo can rival "SBC torque" approaching 3500-4500rpm ranges given they all flow more than 350hp.
The new garret stuff isn't better because it spools faster than X. An old T3 turbine housing is extremely efficient, even compared to new stuff, because efficiency is only increasing 1 or 2% over the last 15~ years. The weights of the shaft are similar and energy is energy, exhaust is exhaust, there is no magic bullet for that.
The new garret is superior because it can support more flow rate on the top end and highly boost with less leaking, superior manufacturing, etc... they are more tightly designed, balanced, better materials in theory, small changes to the housing and wheel, stuff learned from computer aided design and stress testing over many years.
I tuned a couple small turbine garret versions and they do not impress me for the price, turbine is too small, boost too high, and the packaging from mazworx sucked although that isn't garret's fault. I found myself being fickle with the meth addition rate approach 25psi of boost, very hard with Power FC to blend the maf tuning for a stand-alone meth system into that. But I digress
The turbos that impress me are the physically large EFR and similar variety, may not spool so fast but give the 2L 3L the top end it deserves without the tiny turbine and high boost pressure. And they are much cheaper, BW turbo you can $450 for the unit or around $800 complete I think. And they support any power you want top end with as big of a turbine as you want... I'm a big turbine fan
I never suggested anybody buy a 50 trim turbo btw, I am not even sure where you would get one these days or if they exist. I was just comparing the 'free' turbos with the $2000 turbos in a comparison contrast situation. If I knew this day was going to come I would have spiked up the boost a bit on my original graphs to show 350lb-ft of torque before 4000rpm to get you guys some idea. It is absolutely easy and possible I was just being careful in 2007 as a new to 2L tuning, heck I just found out what a skyline is around those years and still had an SBC in a car somewhere.
As always appreciate the discussion, if you really want a nice comparison maybe dig up some more dyno graphs. I've seen one from Enthalpy where he tuned like 600lb-ft out of a stock 3L by 3200rpm or something ridiculous I forget what turbo though. Its nice to compare.