KA-T with a small turbo

[hannibal]

Everyone talks about using T3/T4 turbos. I understand that a T3/T4 is great if your going for major power. I would like to talk about smaller turbos like the T3 and SR T25/T28. I think these are able to make decent power with fast spool and little lag.

I personally thought the T3 was the smallest turbo that should be used on the KA. But I read a old thread that mentioned AceInHole's setup. To summarize, he made 274.6rwhp @ 5250rpm, 310.38rwtq @ 4050rpm at "peak boost of 13.3psi" (guess it falls off up top).

His setup: T25 turbo on a '95 KA with 248/ 232 cams. 4bar fuel setup with 370cc injectors, s-afc, and z32 MAFS. SS autochrome modified manifold, 3" downpipe, 2.5" RT cat, Greddy DD exhaust.Dyno sheet and setup

He didnt mention anything exotic like race gas and alky injection. But I believe the cams make a big difference.

I havent seen any T3 dynos making close to 275whp. But if a SR T25 can do it, a Z31 T3 should do it even easier. Does 300whp (at 15psi) seem like a reasonable goal for a Z31 T3? And how is AceInHole making such good numbers on such a small turbo?

I'm a big fan of the T3. Ive heard its good til 15psi and I wouldnt push a stock KA past 15psi without some excellent tuning (standalone, etc). Just wanted to hear your thoughts on the matter...

Z31 T3 specscomp wheel: T3, 60 trimcomp housing: T3, 0.60A/Rturbine wheel: T3, stg 1turbine housing: T3, 0.63A/R

S13 SR T25 specscomp wheel: T25, 60 trim (60mm)comp housing: T25, 0.80A/Rturbine wheel: T25, 62 trim (53.8mm)turbine housing: T25, 0.64A/R

S14/S15 SR T28 specscomp wheel: T3, 60 trim (60mm)comp housing: T04B, 0.60A/Rturbine wheel: T25, 62 trim (53.8mm)turbine housing: T25, 0.64A/R
Modified by IWannaS15 at 10:01 PM 12/2/2004

[sil80drifter]

I am also very interested in this topic. I've seen SR guys make 290ish rwhp on their t25s (at higher psi levels). Clearly I think that's the upper limit for those turbos, and they probably don't live very long if boosted like that every day, but then agian t25s a re almost a dime a dozen, so if you get one for 100 bucks, and it lasts 6 months, and then u get another one, i think it's not too bad of a deal. I have a T3 sized turbo, and on an RX7 my friend maxed it out at 268rwhp. I think this was an issue of exhaust flow, as the rotary makes quite a bit of it at higher rpms, and the turbo gets chocked. But again, I don't see a reason for a T3 not to be able to do good upper 200s rwhp or low 300s, if the t25s can provide such numbers on a KA-T or SR setup.

sil80

[RMiller]

I've recently read several posts about using a t25/t28 on the KA. It would be fun, but I think it'd be even better with a rb25det turbo or the z31 turbo like you mentioned. The factory put the t3 on their larger displacement engines for a reason. By far the best oem Nissan choice for a smaller turbo would be the rb25 t28, it rules. Next I recommend either a z31 turbo or a GTiR t28.

The reason I wouldn't get other t25 flanged Nissan turbos is because I think they might lower the potential horsepower you could make. Is AceInHole's cam setup a 248 intake cam, 232 exhaust cam? If so, that contributes to his really, really high torque figure, and low power peak at 5250 rpm. Since the motor naturally peaks at 5600 rpm (at least on a 93), I would try to find a turbo that breaths a little better than a t25 for a 2.4 liter on the turbine side.

Now, here's why it's usually better to get a t3/to4. You can choose compressor covers (this applies to Nissan turbos too, but you can customize the t3/to4 even more). You can choose the wheel trim and wheels (Stage 3, 5, etc.). You can choose the a/r from .48, .63, .86, etc. You can do all this for about $600 or less, and you get a brand new turbo. Most people with SRs or CAs upgrade to Nissan turbos because they bolt right up and can be found for cheap. This is interesting: I think the Evo Big16G is one of the best turbos you can buy, and they're pretty cheap and can be found used. However, the flange is DSM specific and I would never make a custom manifold just to run that turbo. If I was going to get a new manifold, it would probably be a t3. (fyi I have a ca.)

[hannibal]

...t25s a re almost a dime a dozen, so if you get one for 100 bucks, and it lasts 6 months, and then u get another one, i think it's not too bad of a deal.

Dude, youre reading my mind. A cheap OEM turbo capable of 300whp would be awesome. You could blow up KA's and turbos all day and be running again for $400. Thats the perfect setup for a newbie.

By far the best oem Nissan choice for a smaller turbo would be the rb25 t28, it rules. Next I recommend either a z31 turbo or a GTiR t28.

Is AceInHole's cam setup a 248 intake cam, 232 exhaust cam?

Those other turbos sound good. Theyre more rare than the Z31 and SR turbos though. I'm interested in their specs.

I think youre right. He said something about rotating the 248 cam 4 teeth and IIRC that applies when the exhaust cam is used on the intake side. AceInHole does a lot of autoX so he was looking for low rpm power.

[coolcloo1019]

I'm going ka-t in a couple weeks and i am using the SR T25...so we'll see

[:: orion ::]

Reason you don;t see many T3s at ~300rwhp is that guys use them for cheap junk yard setups...and typically don't give them enough fuel for more than ~240-250rwhp.

It's either and FMU or 370cc injectors and an AFC with a T3. Guys who go bigger with fuel and timing management, go bigger with the turbo.

That being said...the Z31 T3 can do 300rwhp easily...300ZX guys do it all the time (Z31 that is).

I really like the feel of a T3 ona KA...spooling by 2500, and nice hard pull through the revs, LOADS of TQ.

I also happen to have one for sale, off an '84 300ZX (oil cooled only).

Z31 T3 for sale...seems to be in great condition, although I haven't gotten a chance to run it...sold my S13 before I could play!

- Brian

[MarkEmark]

Everyone talks about using T3/T4 turbos. I understand that a T3/T4 is great if your going for major power. I would like to talk about smaller turbos like the T3 and SR T25/T28. I think these are able to make decent power with fast spool and little lag.

I personally thought the T3 was the smallest turbo that should be used on the KA. But I read a old thread that mentioned AceInHole's setup. To summarize, he made 274.6rwhp @ 5250rpm, 310.38rwtq @ 4050rpm at "peak boost of 13.3psi" (guess it falls off up top).

His setup: T25 turbo on a '95 KA with 248/ 232 cams. 4bar fuel setup with 370cc injectors, s-afc, and z32 MAFS. SS autochrome modified manifold, 3" downpipe, 2.5" RT cat, Greddy DD exhaust.Dyno sheet and setup

He didnt mention anything exotic like race gas and alky injection. But I believe the cams make a big difference.

I havent seen any T3 dynos making close to 275whp. But if a SR T25 can do it, a Z31 T3 should do it even easier. Does 300whp (at 15psi) seem like a reasonable goal for a Z31 T3? And how is AceInHole making such good numbers on such a small turbo?

I'm a big fan of the T3. Ive heard its good til 15psi and I wouldnt push a stock KA past 15psi without some excellent tuning (standalone, etc). Just wanted to hear your thoughts on the matter...

Z31 T3 specscomp wheel: T3, 60 trimcomp housing: T3, 0.60A/Rturbine wheel: T3, stg 1turbine housing: T3, 0.63A/R

S13 SR T25 specscomp wheel: T25, 60 trim (60mm)comp housing: T25, 0.80A/Rturbine wheel: T25, 62 trim (53.8mm)turbine housing: T25, 0.64A/R

S14/S15 SR T28 specscomp wheel: T3, 60 trim (60mm)comp housing: T04B, 0.60A/Rturbine wheel: T25, 62 trim (53.8mm)turbine housing: T25, 0.64A/R

Modified by IWannaS15 at 10:01 PM 12/2/2004

Small turbo's aren't all that bad...I've been running one for one and a half years...according to those specs, mine is even smaller than the straight T3 you mention...mine is a t3 super 60, 60 trim, .60 a/r compressor, .48 a/r turbine...has virtually no lag...the throttle response is EXTREMELY impressive, and it pulls pretty hard all the way up to 5000 rpm...

At 9 psi I got a 13.86 @ 109 mph according to my G-Tech. Obviously the high ET is due to my being a terrible driver, and this is a bit faster than a time I'd get at a track because it doesn't take into account reaction time...but then again every single car tested by car magazines don't take into account reaction time either.

At 9 psi it also got 5.16 seconds to 60...

That said, when I rebuild my engine (hopefully this summer), I'll see how this turbo can handle 15 psi, and will most likely upgrade it to a t3/t4, along with 550 cc fuel injectors, a different MAFS and a re-tuned ECU. But all-in-all, for low amounts of power and for all around streetability I'm pretty satisfied.

[RMiller]

I don't thing 1/4 tracks add your r.t. to your e.t. Time starts counting when you start moving. r.t. matters when you're racing side by side.

[hannibal]

Hey Mark, Ive followed your setup. You started off with a smaller comp and found it was dropping boost very early. As you said, your current turbo is very similar to the Z31 T3. The Z31's bigger exhaust housing wont spool up as quick as yours, but should hold boost almost til redline. Have you dynoed with either setup?

And once again, awesome website!

[fastpace]

I am going to test the limit of my T-3 super 60 this winter break once I get the bugs worked out. I think I am probaly one of the only ones that has the fuel to test the power out put of a T-3.

[MarkEmark]

Hey Mark, Ive followed your setup. You started off with a smaller comp and found it was dropping boost very early. As you said, your current turbo is very similar to the Z31 T3. The Z31's bigger exhaust housing wont spool up as quick as yours, but should hold boost almost til redline. Have you dynoed with either setup?

And once again, awesome website!

You're right, I bet my turbo with a .60 a/r turbine would hold boost quite a bit better and not "choke" the engine like a .48...but I really have no idea. No, I haven't gotten the chance to dyno it yet, and I don't know why....been too lazy to drive it pretty far to get it dynoed...I need to do it soon though, but I'm planning on rebuilding my engine this summer so I should probably do a dyno before the rebuild and after it.

When I do rebuild the engine I'm not going to mess around with a T3..I'm going to go straight to the tried-and trued T3/T4...probably 57 trim or 51 trim, i forget which one is supposed to be better for which boost but i haven't researched turbos for like over a year.

fastpace--how much boost are you planning on running to test the limit of the t3 super 60? what is your setup? any dyno #'s so far????

[fastpace]

I am going to try at three boost levels. One is stock wastegate which is about 7.25 psi, secon level is going to be 11.75 and the third setup will be 13psi.

I have stock block with jwt ecu 50lb and cobra program. I have 550cc injectors and walbro fuel pump for the fuel management.

[hannibal]

I never considered that most small turbo guys dont have fuel setups to max out the turbo. I'm interested to see what kinda numbers the T3 will make.

Fastpace, I think you should be close to 300whp at 13psi.

Do you guys know if the Z31 turbo has a steel or ceramic wheel??

[:: orion ::]

Steel.

[AN89HATCH]

will an sr t25 choke the ka? and about what rpm, will the boost drop off?

[:: orion ::]

Look around FreahAlloy.com for "AceInHole"...he has a T25 on a KA, and has posted numerous threads about it, a few with dynos.

- Brian