Twin turbo UZ ST185

[JustenGT8]

It's a Bullet manifold. Their early version. I think once the company restructured they had to find another source? either that or it was just to expensive to produce and the Richwood one was an easier alternative. Super light bit of gear.

 

[quadcam boat]

How did you get hold of it?
Do you have any photos?
Thanks,
Andrew

 

[JustenGT8]

Just lucky i guess

No pics off the car but as it just sold i'll be pulling it off and will grab you a pic then.

 

[gte]

Make sure to dyno it before you sell it or take it off of the car!

 

[JustenGT8]

OK you impatient buggers, car was dynoed this morning....results will blow your mind and make some (like Cribbj) cry

Just trying to fire up the scanner at home to post the dyno sheet. Dynoed on my reference dyno so can show TT versus twincharge.

 

[JustenGT8]

OK pics 1st, explanation after



Now the dyno is my reference dyno and occassional tune tweak. The runs are both with the ex gates set at 12psi........does produce a little more though. The lower run is approx 315rwkw and is the setup i ran the 1/4 tim,e and WP time on. The 377rwkw is the twincharge (obviously) with yet again wheelspin top end. Equiv the the 17psi run i have done as turbo only......big difference is with the SC it took 25psi!!!!!!! to get there.

Bottom end torque is wild...250rwkw @100kph in 3rd which is roughly 3000rpm (will have to work it out and come back and edit). The other widl thing is that a stock internals 1UZ with 10:1 comp took 25psi!!! no probs. UZ with WI FTMFW

There was some igntion breakdown right at the top end but can't expect too much from, the poor stock coils/dizzy

Anyways, as a proof of concept exercise i think the results are good. I will need a bigger SC to get the top end flow back but the little M90 is pretty good for most of the run. Top end will also be impacted even more by the stock intake and tight turbine housings so there is a bit further i could push this setup but i'm off on another tangent now so stay tuned

 

[cribbj]

Now the dyno is my reference dyno and occassional tune tweak. The runs are both with the ex gates set at 12psi........does produce a little more though. The lower run is approx 315rwkw and is the setup i ran the 1/4 tim,e and WP time on. The 377rwkw is the twincharge (obviously) with yet again wheelspin top end. Equiv the the 17psi run i have done as turbo only......big difference is with the SC it took 25psi!!!!!!! to get there.

Bottom end torque is wild...250rwkw @100kph in 3rd which is roughly 3000rpm (will have to work it out and come back and edit). The other widl thing is that a stock internals 1UZ with 10:1 comp took 25psi!!! no probs. UZ with WI FTMFW

There was some igntion breakdown right at the top end but can't expect too much from, the poor stock coils/dizzy

Can't see the pic Justen because of our IT Gestapo, but from your description it sounds impressive. But are you saying that it took 25 psi boost to hit 377kw in twincharge mode, vs only 17 psi in TT? I don't have the SC drive requirements in front of me, but I'd have thought you'd lose only around 15 to 20kW max, in driving the SC. 8 psi sounds like the SC is taking a lot more than that.

25psi is certainly an incredible figure for a stock internal 10:1 1UZ. Makes several of us with $10K+ built (and me with a broken) motors wonder WTF did we spend our money on and for?

I think your water injection, intercooling and fueling are the key points that let this high compression motor live at these boost pressures. That and the OEM's quality build of the motor, vs a sloppy aftermarket job.

Edit: Not to infer that all aftermarket "builds" are sloppy. We all know that a built & tweaked motor done by a pro at the top of his game will be far superior to an OEM build, especially if quality components are used. But there are Real Builders, then there's the rest.....

 

[JustenGT8]

Yeah 17 psi TT was over 400rwkw.....twincharge was 25psi for 377rwkw (but with wheelspin so prob also close to 400rwkw). It's not parasitic losses doing the damage but poor flow from the SC/SC manifold.

God knows what 25psi from, TT setup would produce but more than the stock rods would handle that's for sure

bottom end and mid range torque are super strong with the twincharge though

 

[cribbj]

That's really interesting...... do you have your charge air temps in the manifold for both cases?

Also, where's your boost sensor mounted?

 

[JustenGT8]

Yup TT was 30 deg and TC was 40 deg. Both air temp sensor and boost feed are from the SC manifold ie after all boost devices

 

[pwd]

Very impressive Justen, a 3.3 litre Whipple would be a good upgrade.

Nice to know I can throw a few more pounds at mine soon, no where near what you are doing though.

 

[cribbj]

I checked the drive loss curve for the M90. Assuming you were doing 10psi worth of compression with it at 12,000 RPM, you'd have around 30kW of losses driving it. Wonder if 30kW of drive loss equates to your additional boost required?

I'd have thought the drive loss would be worth a few psi or 4-5 max - not the difference between 17 and 25psi.

So if you can make the same RWKW at lower boost (ie less stress on the motor) with a turbo system, then the only compelling argument for the supercharger is the extra low end torque it gives. Which is sorta what we've been saying all along.

To me, this result may be a good argument for running the systems in parallel, not in stages. Down low you run the SC only, then once the turbo has spooled up, declutch or unload the SC to minimise its parasitic load on the motor.

It would be really interesting to measure what the pumping losses were at each point in the whole intake system.

 

[Zuffen]

Don't forget boost figures are representative of both thte amount of air the compressor is producing plus the restiction it is meeting in gettig into the cylinder.

Could it be the system is now so restrictive you need more boost to get the same amount of air into the cylinder?

Assuming it all flowed more air the boost would drop but the flow would remain constant or perhaps even increase.

Regardless, excellent job. You're showing the rest of us how to do it!

 

[JustenGT8]

Yeah some weird results there. My early summation (this will need a few sleeps to fully think thru) is great gains down low as you would expect. brings the turbos on quicker too so a double bonus. Mid range is also good and SC doesn't look to be a restriction. Top end is where it starts getting weird?

I think the SC is having some restriction. The pumping losses would also be for something approaching the full 25psi as it's still working with 12psi on top of the 5psi it's running at. So there are 2 areas of concern. The 3rd is the actual manifold....a manifold pressure of 25psi should be making more power you would think? All i can guess at this stage is there are some weird reversions going on in the manifold that are really hurting flow? I have yet to be impressed with any of the SC manifolds i have seen (with the exception of the inverted styles like the Jag XKR).

I think a bigger M112 would remove some of the top end restriction and the pumping loses would also prob go down? The manifold is gonna need some work.

 

[cribbj]

You're right about needing a few sleeps to sort this out; I feel the same way. That's why I was asking about your charge air temps, and the location of your boost sensor.

IMO, if you're seeing 25psi "in" the manifold, then the motor is making the power. It's just being lost again in the belt drive for the SC.

That is unless something has changed in the exhaust system since you made your TT dynos, or the ambient temp has changed dramatically, etc.?

Is it possible you have more exhaust restriction now, or smaller A/R turbines, waste gates set higher, etc?

Any idea what the boost was post turbos, but presupercharger?

 

[JustenGT8]

Yup boost was 12psi post turbo pre SC. Nothing has changed in the system, other than the addition of the SC/manifold.

Calculated boost based on PRs should have been 22psi so pretty close to the theoretical.

We don't know what the TT system would have delivered at +17psi so it's remotely possible we would have seen the same result and the heads/cams have met their flow limit? Unlikely in my view but again could be a contributing factor.....that's 4 possible sources of power limiter all contributing their bit.....?

 

[NZ_V8farmer]

a guy i spoke to at meremere drag way here in NZ runs a twin turbo 1uz with custom intake manifold, twin intercooler, ported heads and steel head gasket and arp head bolts and running it 17 as turbos were justg rebuilt. he said he's ran it right up to 32 psi, but normally 27psi. hes got standard internals minus the head work. standard cams too. ignition has been upgraded. he said he's never had a problem with standard internals and people never believe him when he tells them hes runnning 850hp.(think that was at wheels but cant remember) runs a record of 8.88 seconds down the quater.

 

[saahild]

Very impressive stuff there mate. And makes for some interesting reading there. But dyno figures are dyno figures. In your opinion, when it comes to driving it, is it worth the extra cost and complication of twin charging it over the twin turbos?

 

[JustenGT8]

Very impressive stuff there mate. And makes for some interesting reading there. But dyno figures are dyno figures. In your opinion, when it comes to driving it, is it worth the extra cost and complication of twin charging it over the twin turbos?

Nah mate you are nearly right...it should read "there are dyno figure and there are dyno figures"

These speak for themselves....how do you think 250rwkw @ 3000rpm feels It's a torque monster. As to whether it's worth it...depends on what your purpose it. As a streeter that'll run an easy 10 sec 1/4 then this is definitely a good way to go. As a circuit car i would just stay TT.

BTW there's bugger all extra complication. The SC setup is as tidy as the stock intake. The pulley belt is longer, that's about it. Cost is cost, i know some who have spent more on a single T setup...in fact a rebuilt n/a engine would set you back more than it cost me to set this up :biggthumpup:

 

[saahild]

I am pretty sure that is more then what the stock supra TT makes at its peak power band . So for a street car this is good. But why would you not use it as a circuit car? Restrictions at the top end of the rev range? (where you would be for most of the time on track). Wouldnt a bigger supercharger solve that problem?

The lack of extra complication is very nice though . Just have to figure out if and how this will all fit in my little mx5 now . How much higher would a supercharger sit above the normal engine? Width wise I am sure I will be fine, just having some concerns about how much height clearance i have.