We mentioned we are testing the 88mm prototype that became our new 92mm 103/92 T4 SUM-270112R Giant Slayer. JP Riccio had a chance to take it to the track yesterday in his 5.3L T56 FC RX7 and it didn't disappoint!

His previous best was 9.35@154 at 28psi with an upgraded 78/75, 6.0 SBE, stock heads, SUM-8723R1 and Holley Low-ram. He broke a ring land that day so he picked up another 5.3. This 5.3 is also stock other than a small stage 1 cam and unknown (if any) valve springs (more on that in a bit). This is the one that picked up 200whp at 2PSi less boost than his 6.0 and 7875. The rest of the car is a pretty basic extreme budget build. Terminator X, 4" intercooler, 4" down pipe, VS gate, VS 210 injectors, stock coils, Summit Pro Twin clutch and a couple Summit inline pumps for fuel. No modifications were required to put the turbo in (92mm 270112R is the same housing too).

Anyway, he got it down to an 8.85 @ 163.22 yesterday. No 2-step and lifting on every shift. Picking up about 9 mph and half-second with the new turbo at the same 27.5 lbs. This is MASS FLOW friends . He tried for more boost even yet, but the MBC was maxxed and it smashed through all the boost safeties before fragging something in the driveline in the burnout box.

So what's next? The turbo has a lot more left in it, but we may be out of test days in Ohio. He has the bigger SUM-8723R1 and the SUM-174005 .630 beehives and may go back to the dyno with our SUM-270101R 60mm Piston style gate to turn some rpm. It really needs a set of Pro LS pistons and rods so he can let it turn anything it wants. We don't know how fast anyone has gone with a SBE 5.3 and T56, but it looks like the Giant slayer is one killer T4 turbo for folks who don't want to cut up their engine bays. The extra 4mm of compressor in the production turbo will have even more punch so we're going to see a lot of T4 guys breaking their own records!
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I saw that on another site, he was def making power.

 

Thank you sir, that is high praise and we appreciate it!

 

Curious on the update from 88 to 92 and if you guys tried them both on the dyno etc? Any info to share on that, power or backpressure changes etc?

 

The 92 wheel had been tested in our T6’s with this turbine wheel but not in a T4 housing. With the same footprint and negligible cost or weight difference, it made sense with the 112R. The 88 in JP’s car has a lot of wind left in it but ultimately would go faster with the 92. That…we know. Honestly he’s going to need a lot more short block before we can truly explore the rate at which Back-pressure offsets gains. And we think him doing it in his car, at his dyno and Dragway 42 is probably the best way to get the info out there. It’s real world.

We have two dynos we run eight hours a day for validation work but sometimes it just isn’t the same. Our Project 1000 twin turbo 408 was needed for what it was. A recipe some of our less experienced customers could look at and trust things would go together properly. At the same time, that engine doesn’t really resonate with a lot of our customers like JP who “just wants to go faster with what he has”. Well, personally…many of us working at Summit Racing fall into this second camp lol.

As guys know from our Pro Ls cams, we have a disdain for “black magic/magic pookie” sales tactics. We put every spec right out there and offer things like the cam timing calculator for people to educate themselves. We can’t save everyone from poor (and expensive) bad decisions, but we’ll keep on ‘tryin. It’s the best way to live.

 

I agree with all of that just always looking for more data to back up what I have seen or discovered myself over the years Anyway keep up the good work over there.

 

Amazing those wheels that size can be fit in a T4 style. Wonder why nobody has tried this previously. The T88 was the biggest for the last couple decades, nice to see the T4 isn't left for dead. Would love some spool comparisons.

 

Thank you fellas. Jp still has his V2 7875 as a reference. Getting spool and back pressure numbers is the plan BUT he’s going to need a Pro Ls shortblock before we could hit 2:1 with the 112R. It would be nice to turn it up to 40 Lbs and see if it’s falling off much at that point. Anecdotally he’s telling us it spools the same as what he had, but hard data is needed.

Testing the 112R against an 88 or bigger T6 would be neat but we’ll need to find another candidate with more room in the engine bay. Many less expensive T6’s still don’t have the 112R’s 103/92 turbine wheel, so not just any T6 will beat it. The aero on this compressor and turbine are particularly good and a surprisingly nice match for the 4” downpipe. With 112R effectively being a very good T6 in a small quick-spooling T4 body, quite a few turbos become obsolete.

 

Do you have any thoughts on running these new T4 offerings on a larger ci motor? I’ve got a 403” motor with a T6 475 on it right now and it’s fine, but faster spool up is always cool. I already have a summit turbo manifold laying around that I bought when they came out as well….

 

I'd stick with your current T6 setup and move to a billet wheel 76mm and maybe even with a smaller turbine if you want it to spool faster.

 

We do have some thoughts and it's almost an open question because of what it means to "Turbodom",

When we see 112R spool as quick as JP's 7875 on a cam-only 5.3, is there a reason to go smaller than a 92mm compressor or 103/92 turbine on any engine? He's already got it making 1000 by 7k rpm so nothing about it is saying it's too large even on a 5.3.

Here's the harder decision to the question you asked. BOTH the T4 SUM-270112R and T6 SUM-270107R have a 92mm compressor and 103/92 Turbine. The T6 has a 1.32 A/R versus the 1.25 A/R in the T4. The T6 is rated between 1300-1550. The T4 between 1150-1350. The T6 flows a bit more air but it's bigger and heavier. The T4 spools quicker but lighter and smaller. Which turbo makes JP's car with a 5.3 accelerate faster? with a 6.0? or with a 408?

It's looking like EVERY car should probably start out with 112R. It's just more responsive. When you hit low 8's or high 7's with 40 lbs. and 2:1 backpressure, then the 107R begins to make some sense,

 

All I see from some people is that a T6 will spool faster than a T4. Would love to see some comparison data instead of all the anecdotal stuff.

 

Hey guys.

I saw many questions where answered, but if you have any other questions about the turbo/my car/the set up, feel free to DM me (FB probably faster as I am not on here much)

FaceBook----jp.riccio.5

And follow the build here https://www.instagram.com/lsjuanrx7/

The set up is shockingly simple-and this turbo is really the only reason its going this fast! Also, in better news it looks like the trans and clutch is OK as I made some street rips yesterday, and all seems well. Looking back, I think I just got the clutch fluid hot from hot lapping the car and pissed off the TOB. So, I may try to get back to the track with more boost, or, get back to the dyno and pin the gate.

Stay tuned!

 

Where is this turbo made at? (SUM-270112R)

 

I vote to pin the gate…

 

The 2600 series parts are Chinese. The 2700 series parts including the turbos, piston style gates and bov’s are Canadian.

 

Currently, I run a BW 85/96 T4 1.25 on a 11:1 forged 408, Trick Flow 220’s, 226/230 cam, etc.

I have room to mount your SUM-270112R Giant Slayer turbo in the existing area.

Wonder what the difference in power would be, if any?

 

Our wheels are considerably larger and the downpipe flange is immense compared to normal T4’s. This turbo on a 408 has done 1100 at 25 lbs. and has enough extra it can lift heads unless “specialer” stuff is used to hold them down. You might be looking at a couple hundred over what you have currently when you turn it up to the same net turbine inlet backpressure ratio. Meaning it might be 36 instead of 26 lbs, BUT where your old turbo was done, this one still has a lot of overhead before T.I.P. strangles it to the same extent. So when you get your number, simply saying “I added more boost” doesn’t really explain it. You would need to tell folks the turbo “allowed you to add more boost reliably” if that makes sense.

With the various ways people measure and figure horsepower these days, the biggest thing is for you to use the same methodology as you make changes.

 

@Summitracing what type of turbine wheels are you guys using?
I've been reading an interesting thread on another forum about Impulse vs Reactive turbines with the prior being used for years by borg in diesel engines and the latter being used in the newer Garrett models which are designed for gasoline type engines.
Definitely worth looking into as the guy who's documented the switch is making a lot more usable power.

 

Thank you. This is a touchy subject but know where you are going with this . All we can say is they’re designed to operate more efficiently than most 10 blade turbines. We reduce back-pressure across the nozzle while producing the torque required to spin our compressor wheel designs. We’ll have to leave it at that.