T3Super60 Dyno
 

So I got around to getting my car dyno tuned this past week. I had tuned it myself up to 14.5psi and made 246 wheel but I wanted to turn things up a bit.
Setup is a fairly old T3Super60, externally gated on a Begi S5 log manifold (probably not helping me), with a MBC.
Manley rods, Supertech 8.6:1 pistons, kelford valvesprings, exhintake cam, large front mount, rx7 550cc injectors, toyota COPs, 3" artech exhaust all the way back, standard stuff.

So we turned it up to 19psi and had this for results. 277hp, 248tq. The tuner says their dyno reads 20 low on a 200hp car but I'll take that with a grain of salt. So maybe I'm making 300...but probably not unless I see it on another dyno.

So I'm kinda wondering if it seems a bit peaky to anyone besides myself. Plot seems to show power hit and then fall on its face.
I've been considering getting a new turbo eventually, preferably ball bearing. Needs to have a T3 flange and 4 bolt or v-band (I should be able to alter if necessary but I don't want to have to change too much).

Is this rapid drop off from my turbo being around the top of its efficiency? What would be a better choice? I'd like some nice spool as this thing is pretty laggy but I want to be above 300. The car is primarily a street car but I've been taking it to a few trackdays at Lime Rock and Palmer Motorsports Park so I want it to be able to handle the abuse associated with some 20 minute track sessions.

Any general commentary on my dyno plot? Am I leaving alot of power on the table with this old turbo?

https://cimg3.ibsrv.net/gimg/www.mia...13fe87c4a1.jpg

A log of the pull would tell us so much more. Is it holding 19psi until the end of the pull? Where are you sourcing signal for the mbc?

From what I recall, it held 19 all the way to the end of the run. MBC signal is sourced from a port on the backside of the intake manifold.
i had done a boost leak test and the system held 30 psi so there are no major leaks that I'm aware of either.

having run a 100% genuine.48 A/R T3 Super 60 myself, I'd expect a bit better spool and much better top-end.

Right, and this is obviously not a true turbonetics ball bearing T3Super60 but instead some journal bearing version that Garrett made (assuming it's even a super).

https://cimg4.ibsrv.net/gimg/www.mia...75b48954aa.jpg

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So comparing other people's graphs at similar boost pressures, I'm thinking that this turbo might be a bit tired or just too small for what I want.
The question now is do I go to something like .gt28xxr, gt30xxr or something altogether different (but I still want to use my manifold and maybe tweak my downpipe as necessary) .I've been considering changing turbos for a while now. I think I just needed that push to give me a reason .

yeah i never ran it with that much boost -- it's a 300-350CFM turbo, should have enough for roughly 300-350hp or so.

Thats at the flywheel correct? That seems at least somewhat inline with what I'm getting here at the wheels. I verified that it is definitely a .48 A/R turbine housing at least but its surprising that the spool would be so late in that case.

I'd like to be around the 350 wheel area with quicker spool than what I'm getting now but preferably less peaky than what I have now. I'm eyeing the gtx series garretts since I don't want to have to change out my manifold right now. So I'm limited to T3's which I think rules out any of the EFR turbos.
Current thoughts are gtx3071r which has either .63 or .82 A/R available. gtx2863r and be satisfied with 300 with quicker spool (except this is only available in a divided T3, .82 a/r so I'd likely need to knife edge the divider). Or gtx2867r in .82 or .63.

I'm still very new to all of this and definitely not the most knowledgeable... but I think long term cost wise you'd be better to just go with the EFR. change the mani and modify the DP.

No since in shelling out for a new Garrett just to change it again later. Although maybe there is a perfect turbo for you with a t3 flange :dunno:

yeah my 1.6L spooled it quicker. I'd have to find the dynos.

https://cimg1.ibsrv.net/gimg/www.mia...13258e62e2.jpg


green is same turbo with a bad turbine wheel.

blue is same setup (begi manifold) when i replaced the wheel; running about 12psi.

i have other dynos of it hitting 175rwhp at 3.5k:

https://cimg9.ibsrv.net/gimg/www.mia...ff3564b3a9.jpg

the only real difference here was a smaller IC at the time. 12x12 vs 12x18

so on my 1.6L I'd have expected ~20psi at ~4k. your low CR pistons may be coming into play here?

I had a Super60 on my old 1.6 and 1.8 and it would hit 18psi well before 4000 rpm. Think it was something like 3800rpm in 4th gear for the 1.6 and 3400rpm for the 1.8. It also would not drop that hard past 6k, I never had it on the dyno but I feel like seat of the pants you can probably feel your car falling off past 6k on the street. My old T3 actually spooled as well or better than a GT2560R which is quite remarkable. it was one of my favorite turbos I had ever used actually. The S60 compressor map is similar to the GT2560 compressor map in that it really falls hard past 300whp, but it should be able to get close to 300whp on a really efficient setup. I have a feeling your turbine wheel is the restriction here

I would tend to agree. I think the turbo is a bit beyond its prime as well. I've rebuilt it once but it was rough inside internally (turbine had pitting toward the center section), alot of carbon buildup i needed to clean out from when the previous owner had it as I believe he was running it without a restrictor.
I think this is just final push I needed to fully decide to shop for a new ball bearing turbo. The car is a blast in boost but if I get caught in the wrong gear, man is it a dog.
https://cimg4.ibsrv.net/gimg/www.mia...01098552cf.jpg
https://cimg5.ibsrv.net/gimg/www.mia...a455271fbe.jpg

What turbo are you going to go with to replace it? It just makes no sense with the amount of lag you experience with it, but maybe it was just tired and loose causing it to spool slower.

I'm still researching but I'm leaning toward the gtx3071r with the .63 a/r for spool .I think I'd be satisfied with 340-350 wheel with an earlier spool and less drop off at the top end. I'm waffling between the .63 and .82 though .I keep reading different things from different places.

I think the GTX3071 is the turbo to go for absolutely. Definitely go with the .63 hotside the .82 is way too big for the spool you are looking for. The .63 T3 hotside is more than enough, its more similar to a .86 T2 hotside in terms of flow characteristics.

1) that dyno plot looks terrible, and it looks like something is broken. Turbo's don't come on and choke up so suddenly unless there's a leak or something's broken.
2) rx7 550's and almost 300whp? Optimistic to say the least. I think he meant it reads 20-30 too high which would 100% line up with typical dynapack numbers.
3) definitely don't get the large backhousing on the 30r. it will be terrible like Andy says

is this a VICS motor?

Nope, 94 block, 94 head, 94 intake. I had planned on prepping a 99 head when I had the motor built but the head ended up having a broken lifter surround on one cylinder so I had to go with my refreshed 94 head. I'll eventually go with an NB head when I can find one. I'm sure thats not helping me right now.

There should be no leaks. I pressure tested the system to 30psi prior to the tuning session. There's definitely no exhaust side leaks as I think I'd notice that audibly or at least see soot.

something seems to choke it hard though, because that sudden drop past 6 is unnatural for just "running out of breath", and it comes on really lazy even for what it is

Would there be anything I could check on the wastegate or bov to verify theres no issues there? I would think the boost leak test would rule out any issues with the bov though so maybe theres an issue with the wastegate closing fully?

I'll note that during the dyno runs, it didn't go to 19 immediately. It hit 17-18 and then slowly built to 19 toward redline. (from what I can remember)
Or, and this would go along with my turbo thoughts, if I finger spin my impeller, it will spin reasonably freely, but if I have any side-load on it, it seems to stick/resist against the side of the housing. Perhaps at higher rpm/load the impeller is being pushed toward the side, causing it to bind and choke flow. Just throwing out thoughts.

I'd be kinda nervous if it had enough play to be consistently hitting the side.