where's the graph?

luigi

 

I thought the GT35/40s sweet spot was like 18+ PSI?


Anyone push them a little higher? or have a street port?

-Zach

 

The only other time I've heard of a stock motor producing that much power was on a T-78 @ 19psi & an M2 large IC.

Just a fun little fact.

 

Are you referring to Eric's car? I thought they made that at 15psi (pump gas). NO boost before 4K either.
But after 4K, it was a pretty fun ride!
Michel

 

Yes I was talking about Eric M's car, and I could be completely off when I said 19PSI, but...

I do remember thinking (and saying aloud) that it was a hellova lot of boost for the stock motor whereas if it were 15 (where Eric typically ran his car in street trim) I wouldn't even think that was much boost.

 

That was a reman too, so it was pretty fresh as well. Nick (n-tech) tuned it and I do remember him saying 14 or 15psi. I don't think he's back from Virginia yet (>track< event) but I'll ask the next time I talk to him. They may have tuned for race fuel as well which is where the higher number came in. Just remember, the Blitz car ran 29psi on OEM apex seals. I'm sure the engine was very well built, race tolerances, etc...but still!
Michel

 

Maybe I shouldn't post this here, but...we have 300 hp vs. 400 hp. We have 4 variables: 1600cc vs 1200cc, FMIC vs SMIC, the A/R ratios (whatever that is) and ported vs. stock.
I've read, including on this thread, that 1200cc should be adequate for 400hp, so, can we throw that out?
I think I prefer the SMIC; when I look at the length of the pipes and the size of the IC to be filled, it seems to me that a FMIC HAS to produce lag. How many hp can the difference in intake temps be? When Dave showed me 30hp, I was OK with that, IF my theory about the lag is correct.
I don't have a clue about the A/R of .82 vs. 1.06 (or whatever); maybe someone can direct me to a source?
Shouldn't a 'new' motor with a street port be worth something?

 

taking a quote from relvinnian

with a .82 housing and not enough exhaust port size maybe

"The exhaust housing is not large enough to support that kind of port ... and you'll end up with a lose lose situation. It will still make good power, but it will not be optimal. An engine that wants to make peak torque at 7200, may only be able to make it at 6700 rpm due to the built up engine backpressure on the top end. This may seem negligable, but it's not! A couple hundred rpm lift in the torque peak, and torque curve itself, can result in a large increase in power!" - https://www.rx7club.com/forum/showth...hreadid=108700

if rallimike were to swap out for a 1.06 instead of his .82 housing, he may see significant gains with this street port due to the ability to eliminate the engine backpressure?!?

Then again, maybe I opened my mouth before I knew enough about this turbo sizing thing...heheh

gonzo - where are those dyno graphs?

K

 

Rallimike:

1. i suppose you already have midpipe and catback? you need the flow up high
2. hows the health of your motor?..compression
3.hows your a/f ratio?
your problem also could be tuner related...

good luck

 

I can't see the dyno lines, just looks like a blank dyno sheet of paper.

 

Focus grasshoper It's there

 

turn up your contrast...

Nice graphs Toy! Thanks Gordon!

K

 

Here you go guys, at least you can see the lines now, might need to look at one of gordon's original scans to see the #'s



K

 

Congrats with your results, very impressive for a stock ported engine. Looks like the turbo is living up to its hype.

 

Poweraxle
I hope my 'signature' aswers your questions, but, yes, I have a high flow cat and PFS catback
The motor is a new reman, street ported by KDR
Don't know my a/f mixture, but Dave said the 'lamdas' were great???
Both cars were tuned by KDR

 

Mike,

Your .82 A/R is the problem. The GT3540 is a T3/T4 turbo in essence. You need a decent sized A/R like the 1.06. Even with a normal T04, you would need to run a 1.00 A/R or higher to get good peak HP.

 

The high flow cat is probably hurting as well.

 

do a dyno run with a midpipe on..ive seen APEXi RX6 turbo put out 375-395 rwhp on a ported motor..and the RX6 turbo is a "baby" turbo with a tiny turbine housing and manifold flange

 

how many pounds of boost was that though? The guys at XS told me that with a stock motor at 15psi I can expect to make 380-390rwhp (w/a power fc).

the GT 35/40 is living up to its hype, but does it build boost around 2000rpms?

 

very nice numbers man!! I can't wait till i dyno mine.

 

Hey Gordon, did you get the other sheet? the one where i actually hit 401.8? We hit that 397 at about 15psi so we decided to just nudge it up a tiny bit to break 400.

i think the turbo actually starts building boost at 2500rpms and full boost on low setting at 10, by 5000? Don't quote me on this. i haven't driven the car since driving home from KD...feels like it's been forever. I will try to take it out for some runs today or tomorrow, if i get home from work early enough. I'm not sure how it compares to stock sequentials because it's been so long since i've driven one in that form but lag is very minimal...i'm tempted to say it's close. It seems that the turbo is always ready to go at a moments notice...it definately does not lag like non-sequential.

 

The car had a resonated midpipe on, and Dave did 2 or 3 runs with it, then switched to the cat. The hp difference was negligible, but the cat was slightly quieter.

 

Looking at the numbers, it looks to be a match for the APEXi with better stateside support. What's the price compairison between the GT35/40 and the RX6A?

Definately a turbo to consider for street use.

 

I'm not yet convinced...

I expected to see a lot more low-end output from this setup. Toy, what was the RPM when Dave got on the throttle for these curves? Also, what computer are you running?

Thanks for the info.

 

This is probably the ultimate street turbo, but for big HP applications, I would not suggest it.

Decent numbers anyway!