Project Thread Supercharged Supra

[Zuffen]

Jbrady,

I have that page printed out at home.

The temp rise is only minor but John C was seeing almost 100* increase which he beat with lots of meth.

Something here doesn't make sense as he should only see a minor rise in the inlet temp.

 

[turboandrew]

I forgot to ask about air fuel ratios. Too rich can cause a big drop in HP, and would help explain all that fuel you are using. Did you happen to log air-fuel ratios?

 

[cribbj]

OK, so I've been correlating a data log taken by Mitch to the 498 HP dyno pull data taken by Dennis and I've come up with some interesting results. The table of data and a graph of it are below.

One thing I noticed is that our injector duty on this pull did not go over 76%, however Mitch stated during subsequent pulls that we were at 90% and possibly higher.

This anomaly, and the fact that Mitch was leaning the motor out in subsequent pulls, and we should have made a lot more power than this one, leads me to wonder if the plug with the blown insulator failed just after the 498 HP run, and we were only running on 7 cylinders for the subsequent pulls. This would certainly explain the higher injector duties and all the meth, etc. in the exhaust.

If we have an engine with 8 injectors running 75% duty, then we try to make the same power with only 7 injectors, we're going to have 0.75 x 8/7 = 86% duty. Hmmmm.

I don't think Mitch logged any of the subsequent runs where we were trying to beat the 498 HP pull, as the last log we have shows a time of 2:11 PM, and we were still doing pulls up to nearly 4PM when we had to leave to bring him to the airport.

Edit: This data doesn't show it, but I noticed that our intake air temps, before we came on boost, and before the meth came on, were 145 to 150 degrees, but as soon as the meth came in, they dropped to ambient, then as the boost climbed to 18 psi, they rose another 20 degrees max to 110.

 

[JustenGT8]

That all looks good John.....bar the missing hp? Torque dip is a little interesting but no clue there in the table as to why. Looks like your meth is ON the whole time so that wasn't the issue.

The torque outputs aren't as stable as i would like to see? How 'smooth' did it sound on the dyno? what sort of coupling and drive does the engine dyno use?

That boost and timing on my engine would be an easy 700hp so there's a 100hp or so lurking in there somewhere (allowing for SC drive and higher intake temps).

All said and done though, that torque curve is gonna make for a hell of a ride

 

[spf_lexus]

anyone know the average life span of a standard reservoir of methanol? Is it like gas, do you have to fill up at every fillup? just curious because i would not mind the fill, and even when out it would not hurt anything, just less efficiency until next fillup? I figure 7psi is healthy for a daily driver but add the IC and meth I could 'squeeze" more power from my 7psi?


Just curious but why is there such a large gap between hp and tq at 6900rpm? 498hp and 379tq? wouldn't our engine produce more tq than hp, especially w/ roots? Or is it a dyno attribute?

 

[Lextreme II]

Looks like it needs another 10-11 rpm to get to 500 hp.

 

[JustenGT8]

anyone know the average life span of a standard reservoir of methanol? Is it like gas, do you have to fill up at every fillup? just curious because i would not mind the fill, and even when out it would not hurt anything, just less efficiency until next fillup? I figure 7psi is healthy for a daily driver but add the IC and meth I could 'squeeze" more power from my 7psi?


Just curious but why is there such a large gap between hp and tq at 6900rpm? 498hp and 379tq? wouldn't our engine produce more tq than hp, especially w/ roots? Or is it a dyno attribute?

torque and hp are just a fixed function (hp = torque x rpm) mate so once past 5252rpm torque is ALWAYS less than hp....nothing to do with whether it's a blower, dyno, turbo, n/a etc.

 

[stevechumo]

That's why a small displacement engine with forced induction system usually has severe lag at low speed. It only kicks in fast after certain speed (let's say 30-40 mph and up), and that's when its high hp figure come in and take over its torque. Vice versa, my Tacoma truck has more tq than hp, so after it spins its wheel at dead stop and rolls quick for a very short distance, it start crawling like the turtle. The 1UZ with a forced induction, just as in the case of John, it has high tq at low end and high hp and high end. It'll definitely be very fun to drive at all speed.

 

[cribbj]

Another interesting graph showing the effects of the methanol. (Although the "X" axis is supposed to be RPM, it really is a timeline of the dyno pull, because it starts at 4000, climbs to 4400, then dips again to 4273 as Dennis is opening the throttle and feeding the dyno load in.)

Note how the air temperature climbs from 140 up to 155+ at low boost, but once the meth is triggered on at 15psi, the air temps drop nicely, although the load (boost) continues to increase, as well as the throttle percentage.

Once we were at full throttle and full boost, the air temps did not go over 110-111 degrees F. Without the meth, I'm sure they would have been well over 200 degrees F.

 

[PEI330Ci]

Any updates from across the pond?

 

[cribbj]

Not much to report ATM. Dennis has been up to his eyeballs with other work, but the plan is to sort out the difference in compression from bank to bank, put a cogged belt system to drive the supercharger, fabricate some dyno headers, then have another go on the dyno.

We're also preparing a 2nd 1UZ, which will have a different set of cams and should put out some some interesting numbers. This one will also have 12mm head studs, piston squirters, Lextreme rods, Ross 8.75:1 pistons, etc.

I'm tempted to keep one motor supercharged, and build the other up as a twin turbo. Except for the FMIC piping, the car won't know or care whether it's a turbo motor or a supercharged motor, as long as the intake, fuel, radiator, and exhaust pipe(s) connect in the same place.

I honestly think a turbo motor might be a little easier on the drivetrain than a supercharged motor, as it won't have such a fat torque curve. 425 ftlbs of supercharged torque from the get-go might be too much for even the Supra's mighty 6spd, whereas the turbo motor's torque should come on more linearly with boost and RPM.

We're shooting for another dyno session before Christmas.

 

[hypronet]

Would be nice to see what the final figures are when done.
My engine is ready (after a full rebuild and mods) but just had some last minute changes to the blower drive system before fitting to car.
Plan to have it chassis dyno'd in the next 2 weeks.
Would be nice to compare results on the blown engines

 

[PEI330Ci]

Not much to report ATM. Dennis has been up to his eyeballs with other work, but the plan is to sort out the difference in compression from bank to bank, put a cogged belt system to drive the supercharger, fabricate some dyno headers, then have another go on the dyno.

We're also preparing a 2nd 1UZ, which will have a different set of cams and should put out some some interesting numbers. This one will also have 12mm head studs, piston squirters, Lextreme rods, Ross 8.75:1 pistons, etc.

I'm tempted to keep one motor supercharged, and build the other up as a twin turbo. Except for the FMIC piping, the car won't know or care whether it's a turbo motor or a supercharged motor, as long as the intake, fuel, radiator, and exhaust pipe(s) connect in the same place.

I honestly think a turbo motor might be a little easier on the drivetrain than a supercharged motor, as it won't have such a fat torque curve. 425 ftlbs of supercharged torque from the get-go might be too much for even the Supra's mighty 6spd, whereas the turbo motor's torque should come on more linearly with boost and RPM.

We're shooting for another dyno session before Christmas.

Thanks for the insight into what you've got planned. Very exciting stuff!

 

[cribbj]

Would be nice to see what the final figures are when done. Would be nice to compare results on the blown engines

No problem; my project is an open book ;-) The successes and the failures, or should I say "the near successes that need a little more work"

My engine is ready (after a full rebuild and mods) but just had some last minute changes to the blower drive system before fitting to car.

I'm looking forward to seeing your new blower drive system; from your description in your thread, it seems we're going down the same path with a separate cogged belt drive.

Thanks for the insight into what you've got planned. Very exciting stuff!

It is interesting and fun stuff exploring what can be done with these little V8's. Just a tad expensive though....

 

[PEI330Ci]

It is interesting and fun stuff exploring what can be done with these little V8's. Just a tad expensive though....

I know all about "expensive", I'm currently developing a newer BMW engine...

 

[3barboost]

Hi Cribbj - your comment on drivetrain longevity has me worried ! not to jack your thread but my thinking was the opposite - the transition of low torque to BIG torque as the turbos boost "hits" was what made me go supercharged to prevent the "hit" - am I way off base on my thinking ? I got a lowly W58 behind my uz

 

[XR8tt]

Depends how you drive.. Due to turbo being more load dependant.. When letting clutch out there's less power.. Which gives less shock loading to driveline.. But abuse, power shifting etc they are much the same..
The type of clutch has a big part in shock loading also..

 

[scotturnot]

425 ftlbs of supercharged torque from the get-go might be too much for even the Supra's mighty 6spd, whereas the turbo motor's torque should come on more linearly with boost and RPM.

My biggest fear!

 

[turboandrew]

My biggest fear!

I would not worry about it too much. There was just a Supra in TX who has done 242 MPH in a -standing- mile race (the record at this track by a big margin). That Supra is producing over 1500 rwhp and easily over 1000 rwtq. Yes, 1000 ft/lbs of torque, on a stock V160 getrag transmission. There are not many things harder on a drive-train than top speed runs.

 

[scotturnot]

I would not worry about it too much. There was just a Supra in TX who has done 242 MPH in a -standing- mile race (the record at this track by a big margin). That Supra is producing over 1500 rwhp and easily over 1000 rwtq. Yes, 1000 ft/lbs of torque, on a stock V160 getrag transmission. There are not many things harder on a drive-train than top speed runs.

Must be talking about this guy?
https://email.full-vision.com/exchw...://www.youtube.com/watch?v=PUyf3g5AkI0&fmt=18
I am more worried about the raw torque coming off the line with slicks. Note, on his departure there is not a huge amount of torque being displayed. It almost bogs off the line, not knocking it, that is way impressive!