This was on a 262? 12psi at 46000...

 

Oh i know. If i was doing a track build it would be completely different. Really i never had intentions of modding the cobalt for anything but handling and bolt-ons. Then the mod bug bit. and here i am.

Im looking for a 81 trans am right now as well and will probably drop a LS3 or similiar in it. It might get the track duty behind an auto trans.

 

on the .70 a/r yes.

 

I love the GTX seriers and they are a serious contender for me. I would rather have a GTX over the PTE turbos (no offense to anyone that runs them, they have proven to be great). Just personal bias.


I will take this time to admit one thing i dont get though. Ive seen people push some of these turbos (not mine specifically) to retarded boost levels 40-50psi+. Don't they just become heat pumps at that point? Are they running spray bars on the IC to boost that much and not increase IAT and end up with detonation? The reason i ask is if i could run a slightly smaller turbo and run the **** out of it to like 35psi i would have better spool and power delivery and a higher peak HP. Im just not sure how people are obtaining those boost levels reliably.

 

259/.63 and 8000+ redline on E85 = +600whp add a 6spd zzp tranny...

 

What's the 259/.55ar spool at?

 

While I've never seen that myself, if you're right, not only are they heat pumps but also a serious disintegration risk. Considering the rpms that a turbo efficient in the high 20s/low 30s psi is, running that much over would just be asking for it. Imagine running a (current) LNF to 10,000 rpm...

The old indy series back in the day used to run 1.6L engines, pure Toluene and turbo boost at upwards of 70psi but thats another story.

 

That wouldn't do anything except cause a restriction. The quick spool valve needs to be on a twin scroll turbo and it blocks off one of the scrolls to force all of the exhaust through the other scroll.

 

Will an efr 8374 fit I wonder. Just saw some testing that put its spool well ahead of some smaller turbos. My setup would change a lot going back to an iwg.

Might be some overkill jumping from 55lb/min to 79lb/min lol. The 7670 I believe is 64. I am just looking at everything though as someone tested a 3582r and efr8374 back to back and had better spool on the efr.

I kid though. That would probably never spool on a 2.1

 

That's a big ass turbo, I think fitment would be a "huge" problem tho...

Get it, huge! haha

 

Or instead of this big turbo small at thing why not a 256 with a .84 ar or something. Give up a little down low but ring it out up top. Maybe step to a 259 tho. but if we get the 8k redline you gears don't drop out of power even if you don't spool till 5k rpms. Not going to be a 40 roll car but neither is any other 4 cylinder fwd that has 400+ whp. 50-60 roll in second gear.

 

Yeah I'm just messing around. Ran across some stuff while researching and posted out of boredom. It really would be overkill.

 

Gosh, even on the BNR, 27-28psi and E85, I could barely do roll races at 60mph without spinning. 3rd gear was just about pointless. I'll attribute it to loss of tire meat but still... Dang!

 

no idea. just have track videos. like i said i just spool once, regular shift 1-2 which only takes *snaps finger* that long to spool back up. then nls 2-3. i don't do rolls or anything like that. but, even with that being said, its insanely faster than the 262 .70

this is with just 20psi. maybe 19 wasn't paying too much attention. just know i turned it down to what should be 20psi.

 

exactly. no one is really concerned with that first spool. all thats gonna do is allow you to hook up better. and on cars with a system like an ams1000, adjust your boost to the absolute max that they will hold. once its spooled though, game over, grab gears and hold on.

 

 

7670 for sure. That would be ideal with reasonable spool, and probably one badass powerband.

 

those are numbers i like to see Cmiller lol, not sure bout taht spool time is that to get full boost?

 

That's a pretty worthless test. To start, they have a setup that rightfully should be easily spinning the tires on the dyno. This is the first disadvantage to the turbo that spools quicker. Next, they don't show the boost for the Precision, but then show the boost for the EFR. Then at the end when they overlay the graphs, both boosts are shown, but the new one is higher which tells me that the Precision was tested at higher boost than the EFR, although they claim that they ran more on the EFR. This claim is a red flag in itself because anyone going to this length to perform the test would make another pull with a slight boost adjustment if their turbo was in fact running at less boost than the one they are competing against. Why do I call it "Their turbo?" When I went to the Sound Performance site, the first article I saw had a picture of Precision Turbo's booth at PRI and read, "We would like to first thank Precision Turbo for allowing us to participate in their booth at this years PRI (Performance Racing Industry) trade show..." then i did a search for EFR and it returned 0 results. A search for Precision returned 66 products for sale. Looks to me like their "test" is simply an advertisement for what they sell.

 

Touche

 

Yeah it looks like on the last screen shot they show in the video where they are superimposing the results in white letters over the screen they are only showing the Precision Turbo results. You can clearly see that one run is right about 40psi and the other is more close to 45-50psi which resulted in the higher numbers. The problem is that this last screen shot where they are trying to brag doesn't show the results they claimed at all. BUT, if you do the math it about checks out b/c at ~35-40psi, it looks like the care made close to 1000hp on the Precision.

 

I saw that but was on my phone and couldnt really see the numbers. Thanks for the feedback and breakdown.

 

x2, besides the fact of advertising. Even running both turbo chargers at same PSI wont make a difference. They're not the same size turbo. The compressor maps show where their efficiency range is. The EFR should be at 35 psi or more to be in efficiency range even shown in the compressor map.



Even under the description for the EFR this is a quote:

"The 74mm Gamma-Ti turbine wheel is the optimal match for the 62.6mm inducer / 83mm exducer FMW compressor wheel and is capable of 79lb/min airflow and 45+psi
boost. "

I couldn't even find a compressor map for the PT6266. I really doubt even 30 psi is in that turbos efficiency range. That thing is maxed out while the EFR is barely on a DD tune HAHA. That comparison is straight BS.

 

And you wont find one.....Precision doesnt publish compressor maps.

 

i wonder why though...