300 HP, How to Assemble Our Engines Engine Builders Chime In

[Benjamin A.R.]

21 hours ago, Dudeland said:

Isn't that a bit lean.  I would think you would be looking for 13.5-13.9 afr. 

At idle? 

[Benjamin A.R.]

16 hours ago, xr4tic said:

Megasquirt?  Why not ditch the EDIS module and just run the crank sensor and coils to the MS directly?

Can't really do that with a V3

[Dudeland]

4 hours ago, Benjamin A.R. said:

At idle? 

I will have to look again, but it seems like overall your targets are in the 14's, rather than the 13's.  Just wondering how you decided what targets your were looking for.  My concern would be if it goes lean (for whatever reason) , it doesn't give you any wiggle room before you are detonating. 

[02Coastie]

To the question of AFR’s, he’s running similar to me in the off-boost cruise area, highlighted in blue (I’m NA). It works great and delivers decent economy. The on boost numbers (red) seem plenty rich for FI. It’s the transition between off and on boost that you have to be careful of. I would think as long as the fuel is responsive and ramps up quickly with boost he should be fine. I bet that holset hits hard!

[Dudeland]

11 hours ago, 02Coastie said:

To the question of AFR’s, he’s running similar to me in the off-boost cruise area, highlighted in blue (I’m NA). It works great and delivers decent economy. The on boost numbers (red) seem plenty rich for FI. It’s the transition between off and on boost that you have to be careful of. I would think as long as the fuel is responsive and ramps up quickly with boost he should be fine. I bet that holset hits hard!

I feel that I would want to give up some resolution between 20-70 to give to give me more control when coming on boost.  I haven't tuned a MS system, only my Sniper EFI.   But on second glance it looks ok.  Not so sure about the 15's i am seeing.   I guess you are cruising in that part of the map so it would be ok.   My map is kind wack because I have TBI injection, I have to run fatter because I have a bunch of fuel coming out of suspension at low RPM's. 

 

[Benjamin A.R.]

That table is wonky but it's good enough to not explode so far. More tuning to come for sure. The HX starts to spool right at 3k which is exactly what I wanted. As for targets down low, it's how I had it when it was NA running best. Still have lots to do

[bento]

After a few weeks of putting break in miles on, my turbo 2002 finally got on the dyno for a power tune. They’re still planning to do some final tweaks in the AM and see if cooler temps change anything, but this is supposed to be 90% finished. I’m pretty happy with the outcome as I wanted to stay within range of what a Getrag 245 and E21 diff are proven to be able to handle. I’ll probably run the 6.5psi low boost level most of the time and drop the high boost down to 8 or so from 10psi. 
 

6.5psi power curve is exactly what I was after with peak power at 6k and good power out to 7. At 10psi, the turbo is pretty maxed out. T3 Super 60, 8.6 C/R, ported and polished head, big valves, turbo grind cam.

 

Only notable change planned for tomorrow is to increase the rev limiter to 7.3 from 7k and ensure the tune is clean up there so I can have a bit more usable rpm to stay on the power when shifting to the next gear.

 

Edited May 11, 2021 by bento

[bento]

Some nice improvements in terms of area under the curve from preliminary tune last night to final tune this afternoon. Peak HP was moved to the right by a fair bit and resulted in a very broad power band from 4400 to a bit over 7k. Really looking forward to getting behind the wheel this evening. 
 

I decided not to use the 10 psi boost level for now and will just use 6.5 and 8.5 psi as low and high boost on the controller.

 

 

 

[ray_]

Brent that's gonna be a blast! What's your final drive ratio? Do you have a build thread?

 

Cheers,

 

 

[bento]

3 hours ago, ray_ said:

Brent that's gonna be a blast! What's your final drive ratio? Do you have a build thread?

 

Cheers,

 

 

I’m sure it will be. Had fun putting the break in miles on the new motor!
 

3.91 final drive. It’s no 4.10. ?

 

I don’t have a build thread. Maybe I need to make that a rainy day priority. I have hundreds of photos saved over the years.

[xr4tic]

On 5/10/2021 at 9:53 PM, bento said:

After a few weeks of putting break in miles on, my turbo 2002 finally got on the dyno for a power tune. They’re still planning to do some final tweaks in the AM and see if cooler temps change anything, but this is supposed to be 90% finished. I’m pretty happy with the outcome as I wanted to stay within range of what a Getrag 245 and E21 diff are proven to be able to handle. I’ll probably run the 6.5psi low boost level most of the time and drop the high boost down to 8 or so from 10psi. 

 

 

 

Looking good, but I'll bite, what is the "range a Getrag 245 and E21 diff can handle"?

 

Because usually it's a torque rating and not HP, so if you have an ability to manage boost vs. RPM, you could have the best of both worlds.  Like flipping from 6.5 psi to 10psi at 5500 RPM.

[2002iii]

Supposedly the number of the getrag transmission is the torque rating in Newton Meters, so 245nm=181 ft lbs.

 

I've heard you can get away with 200 ft lbs but not much more. The weak point on the  getrag 245 is the input bearing, which takes the most torque and force of the clutch.

 

I would say the small case differential is good for about the same amount of torque as the 245 transmission. There is a reason e30 325's got the medium case differential.

[bento]

1 hour ago, xr4tic said:

 

Looking good, but I'll bite, what is the "range a Getrag 245 and E21 diff can handle"?

 

Because usually it's a torque rating and not HP, so if you have an ability to manage boost vs. RPM, you could have the best of both worlds.  Like flipping from 6.5 psi to 10psi at 5500 RPM.

 

33 minutes ago, 2002iii said:

Supposedly the number of the getrag transmission is the torque rating in Newton Meters, so 245nm=181 ft lbs.

 

I've heard you can get away with 200 ft lbs but not much more. The weak point on the  getrag 245 is the input bearing, which takes the most torque and force of the clutch.

 

I would say the small case differential is good for about the same amount of torque as the 245 transmission. There is a reason e30 325's got the medium case differential.

 

2002iii’s answer is roughly consistent with what I’ve been able to find, though I hadn’t seen the 245 being the rating in nm before. That’s interesting.
 

I figure there’s some margin in the stated torque rating and I’m pushing my luck as much as I dare by running 240 ft lbs even on a limited basis. This was a better outcome than I expected, so I’m thinking through where to go next. This weekend, I’ll run 6.5 psi on track since I’m mostly just doing shakedown laps, but I know I’ll want to turn up the power eventually.

 

I’m not prepared to start beefing up the drivetrain and adding a bunch of weight, so will think about switching to ecu controlled boost by rpm rather than the external boost controller I’m using today when something breaks. Should be possible to get 260-280hp close to 7k with torque limited to just over 200 ft lbs by gradually adding boost above 5k. Might need a larger exhaust turbine housing as well if I go down that path.

 

 

[jimk]

NT

Edited May 12, 2021 by jimk

[Benjamin A.R.]

Figured I'd post for anyone who doesn't watch my youtube stuff. Got on a dyno for the first time ever, thanks Hoover, Kevin, and Kenton! Made 185 wheel at only 8psi! So 220 crank? Only 80ish hp to go and I haven't even turned up the boost or put corn in the tank.