Can an unported 2g head make 500+whp?

[ZmanIV]

This thread turned into another 2G vs 1G head debate.
I still want to see hard #'s before anyone else says that 1G is better than a 2G at whatever rpm.

 

[gixxerdrew]

There are plenty of people who have done 500 on pump. Heck, I did it with a mix of 93 and 110 octane (used only as a preventive measure if detonation occured), with a conservative map on a 2.3L -- I was only running 8 degrees of timing at 26psi. (Dyno graph attached - 497whp/459tq) The tune had absolutely no detonation or power differences on 93 octane only.

Parts used: PTE SCM6176SP, 2G Ex. manifold, 1G stock head, 264/272 cams, magnus 1G street intake manifold, 2.5" IC pipes w/ PTE large core, 880cc's w/ walboro 255, AEM EMS, 9.0:1 compression 2.3L Eagle/Ross combo.

You will get close if your setup is all working properly.

FYI -- The 50 and 60-trims are much more efficient up to 26psi than the SCMzzzz61 --not a typo -- it is a slow spooling turbo that isn't fun really until after 26psi. It is NIGHT AND DAY when I swapped over to T4 on the turbo, and turned up the boost. It increased my MPH in the 1/4 by 11mph from 122 to 133mph! The 50 and 60-trims have been proven to do 450-550whp on well put-together setups at similar boost levels, but they definitely run out of steam after 26psi.

Who made 550whp on a 50 or 60 trim?? I am completely tapped out at 520whp on this 60trim.

 

[twicks69]

Who made 550whp on a 50 or 60 trim?? I am completely tapped out at 520whp on this 60trim.

Andrew, I did some searching and found several 50-trims in the 500's with the highest being a Miata putting down 576whp/495tq at 30psi on a T3/T04E 50/T3 0.63 A/R with a T31 turbine (stage 3). The same car dyno'd 508whp @ 23psi. Both numbers are on pump gas/meth injection.

There are a number of evos doing around 500-510whp on the 50-trim; I am unsure if they are bolt-on's or T3-flanged.

As for the 60-trims, the numbers were a little harder to find. I ran 12.0 @ 120mph at 26psi and if I remember correctly, it dyno'ed around 450-460whp only.

Again, the higher HP holders of the 50 and 60-trims were on T3 flanged versions, not mitsu flange.

I will keep on looking for solid numbers on these turbos; I usually only see 1/4 mile times out there.

 

[gixxerdrew]

Thanks for the info! Damn those are some crazy numbers. I guess I can see it though. I know I had more in the 60trim too but I was going to have to start doing things I wasnt comfortable with to get more out of it. The #1 problem I had was the backpressure causing the wastegate to blow open and boost falling off. I could have run without a wastegate or plumbed the boost source to the other side of the WG. But I decided that I wanted to keep things in their happy places and move on to a bigger turbo. I was also on a stock cylinder head and mild (relatively speaking) cams.

 

[jkimes]

The 2G MAF becomes a restriction in both ways hertz levels get easily maxxed, and the inlet turbulence is increased with it in the intake tract. Taking it out of the equation, running MAP with AEM EMS was able to pull nearly 20-30HP using a FP 4" intake pipe and large K&N filter only. You can do 600whp on a 2G MAF and DSMLink, but it is a restriction for sure. Also, I am not too keen on using MAF-Translators and GM MAF's -- it is still an airflow restriction placed in a different location. That is why I reccomend using the AEM or equivilant standalone with a MAP sensor and AIT sensor.

So is there a similar solution I can use to meter intake air with DSMlink? I've already spent almost $700 on dsmlink and I really don't want to dump a bunch of extra cash to switch to an AEM standalone setup. There are a few dsmlink users running 8's in the 1/4 mile. How is it that they are able to do this if the maf translator and GM maf combo is such a big restriction?

 

[dsm-onster]

They go 8s inspite of the restriction. . .

Run maft blowthrough for the least restriction and clamp your maf at a frequency just below where the gm maf begins to skip or bounce. The blowthrough setup is not nearly as restrictive as any drawthrough setup including the gm maf. Running piping as large as the gm maf is ideal and could help a little.

 

[1sickgst]

While I can't really comment on a lot of the other info posted here even though I have a stock 2G head on my 6 bolt block, you may want to consider upgrading the valves. The stocks may become vulnerable in that 500+hp power range and possibly separate since they are a two-piece design. You can get stainless valves fairly cheap. I'm not saying the stock valves will separate at 500hp, but better to play it safe.

 

[jkimes]

Twicks... Do you mind telling me which PTE intercooler you are using. I'm currently using a crappy ebay model and I think I may have to upgrade. Considering you made over 700whp with yours I figured I might as well go all out so I don't ever have to buy another one.

BTW.. your car is awesome, I'll be happy if my gsx gets over 500whp much less 740.

 

[twicks69]

Twicks... Do you mind telling me which PTE intercooler you are using. I'm currently using a crappy ebay model and I think I may have to upgrade. Considering you made over 700whp with yours I figured I might as well go all out so I don't ever have to buy another one.

BTW.. your car is awesome, I'll be happy if my gsx gets over 500whp much less 740.

I am running the Precision Turbo Large core air-to-air intercooler with 2.5" IC pipes. No problems over 5 years.

Definitely worth the money spent!

 

[jkimes]

Twicks, How laggy does the divided T4 4088 feel in comparison to the mitsu hotside scm61? Also, how high do your rev your 2.3 motor? I want to upgrade to a divided .96 AR T4 hotside and a divided T4 mani but the performance shop that is tuning my car seems to think it will be way too laggy and not utilize the shorter powerband of my 2.4 unless I go with a smaller .70 AR divided T3 hotside and a divided t3 mani.

 

[twicks69]

Twicks, How laggy does the divided T4 4088 feel in comparison to the mitsu hotside scm61? Also, how high do your rev your 2.3 motor? I want to upgrade to a divided .96 AR T4 hotside and a divided T4 mani but the performance shop that is tuning my car seems to think it will be way too laggy and not utilize the shorter powerband of my 2.4 unless I go with a smaller .70 AR divided T3 hotside and a divided t3 mani.

Heh heh...."How laggy does the divided T4 4088 feel in comparison to the mitsu hotside scm61"....

Actually, the SCM61 spooled around 4500-5000rpms...the T4 GT4088R has FULL BOOST between 4200-4700rpms. It spools up much faster than the T4 version of the SC6176SP that I was running with a T4 0.82 A/R undivided housing also.

It is not laggy whatsoever. I am also running my 2.3L to around 8400rpms with no loss of power or torque at redline. It is a freaking monster.

The GT4088R is an excellent turbo with great spoolup characteristics for the size of the turbo it is.

 

[dsm-onster]

Twin scroll turbine housings . . . the great equalizer .

 

[jkimes]

Twin scroll turbine housings . . . the great equalizer .

Lol.. This is what I was trying to explain to the guy at polk performance but he acted like I was insane to consider running a divided t4 .96 hotside.

 

[dsm-onster]

Yep. Read up on the holset thread. A/R numbers are completely different with divided housings. You cannot compare one a/r housing with another with the same a/r across brands OR types.

 

[DSMunknown]

I did 516whp on a stock 1g head and the 2g head is known to be a better design. That was with just a 60trim. The stock heads can flow. I had a "ported" head before and I actually made more power on a stock head. I realized at that moment that a lot of joe blow machine shops don't have a clue.

It's not much of a surprise. The Evo 8/9 ports are virtually the same size and they do great.

 

[dsm-onster]

That's right. The evo 8 ports are nearly identical except for the reliefs cut for the injectors. . .

[sarcasm]Mitsu must be going backwards. . .

. . . Curt Brown must want ALL the chips stacked against him with the evo3 16g hp record, too. His unported, stock valve 1g head with the e3 16g put down 460whp. Just imagine what he could have done with the 2g head!!! If only he researched his setup. But for some reason he stuck with a 1g head. Just disregard how FLAT his powerband is![/sarcasm].

Of course the unported, stock valve 2g has done 500whp. But. . .

. . . It's like the special olympics. Every one wins. But the head flow is still subpar to a good honda head. Do it right, or don't cheer for your side.

 

[DSMunknown]

The evo head doesn't have the same size ports as a 1g head, does it?

I was refering to the 2G head design.

 

[dsm-onster]

. . . I thought you had come around. The evo 8 head is what I'm refering to. What's the difference between it and the 1g head?

Bud, where's the dyno sheets you were working on!!! This would FINALLY settle this.

The 2g head can do it. . . But most feel the 1g head can do it easier.

 

[DSMunknown]

. . . I thought you had come around. The evo 8 head is what I'm refering to. What's the difference between it and the 1g head?

Bud, where's the dyno sheets you were working on!!! This would FINALLY settle this.

The 2g head can do it. . . But most feel the 1g head can do it easier.

Yeah, I don't count the cathedral design into my equation. As everybody knows, they're only for the injectors. As I showed everyone in the long Evo 3 IM thread, the Evo 8 and 3 ports are very similar, which means the 2G ports are also similar. As pneumo states in this thread, the intake ports on the Evo 8 head are higher. Something to think about without having to take apart an Evo 8 engine. I guess we could always as 95GSXracer about his.

First thing's first. I'm putting on the Evo 3 IM (Finally!) and a larger TB in a couple weeks. The head is most likely going to sit around and collect dust. The reason is because I haven't got the Evo 8 valves or springs yet, as well as a few other things. But who knows what will happen in the next few weeks.