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From naturally aspirated 225 to a boosted 170
https://slantsix.org/forum/viewtopic.php?t=66100		 Page 1 of 2
Author:  lgu32 [ Sat Jul 24, 2021 11:16 pm ]
Post subject:  From naturally aspirated 225 to a boosted 170
Reformulated post:

I like to have a cam suggestion for 170 cu in slant which will have sequential injection and stock compression. Boost estimation 0,5-0,7 bars. E85 fuel only.

Behind of the 170 cu in slant will be 904 with high stall converter (3500+ with naturally aspirated 225) and 7,25" rear with 4,10 gears. <= These parts I will keep

I have an Oregon cam with 236/230 (0,050") degrees. It has been surprisingly smooth in street use.

If not better recommendations are come I will use it. But if a good turbo cam suggestion comes I will try it. Would be nice if it runs from 2000 up and the high power range is 3000-6000.
Author:  lgu32 [ Sat Sep 04, 2021 6:25 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Monology continues:

End of season. Plenty of 15s timeslips. Two times 15,3. A batch of 15,5-15,6 times. Worst was near 17 but it was fun ride. Slipping finally stopped at 3rd gear going on.

139.5 km/h at the end. 5500 rpm. Cast pistons. How much I can go up with 225?

I tested my 225 today. Was running happily at 6500. Probably my cast pistons can do it every this and then.

If I keep my 225 as is and add 0.4 bar boost I probably reach 13.6-13.8 time with 160 km/h trap speed @ 6300.

This is my way to do it.

I will order a t3/4 turbo and add it on this engine!
Author:  Dart270 [ Mon Sep 06, 2021 4:35 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
I keep my cast piston 225 engines at 6000 or below, but maybe you will be lucky? Thanks for the report and keep having fun!!

Lou
Author:  lgu32 [ Mon Oct 30, 2023 11:53 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Tested and inspected for road traffic.

In Finland we have some rules how much power is legal for a car. For this 66Dart the reference is the most powerful model of same car. A 273 4bbl with 235 Sae horsepower rating gives with our formulas 10,7 kg/kW weight to power ratio. The current rule says I gan reach 7kg/kW with my car. As the empty car is 1270 kg I can go up to 180 kW engine power.

When measuring the power from rear axle there has to be estimated some loss. We decided to have 15%.

I had some ideas from road tests how much my boosted and injected 170 will push so I reduced the boost from 0.9 bar to 0.7 bar by replacing the waste gate actuator spring. As well I set the rpm limiter from 6500 down to 5500. At the 1st pull we got 157 kW from rear axle (tires removed brake dynos bolted to the axle). As the engine was running ”without cone wind” it was doing light pinging even I use e85. So I set ignition -2 degrees and the 2nd pull gave 146 kW. That fits to our target to get no more than 180 kW at the engine. (240 hp net)

I am satisfied. I have 240 hp 170 cu in slantsix (and it is limited to that level!)
Author:  Dart270 [ Mon Oct 30, 2023 2:28 pm ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Sounds great. I bet that is quite fun to drive, and should be reliable. Assumedly, you can just turn up the boost after your inspection and just make sure you do not get into an accident.

Running the numbers on my 68 Dart with Torqstorm supercharged 225, I am around 330 HP at the crank. 0.3-0.4 bar leaving the starting line, and up to 0.8-0.9 bar at 6000 RPM. The turbo makes more average and peak power than the supercharger, but is less predictable to drive as the boost can rise while your right foot is at one position, and then overcome the tires...

Lou
Author:  lgu32 [ Sat Nov 11, 2023 12:12 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
I am driving my Dart to storage over the winter. It is now at freezing point but not snow. After I got engine tuned well I have found roads are slippery in all conditions. It is not worth test it on snow even I have old set of MS tires with spikes on them.

For next season I will do for the engine a control valve for the waste gate actuator to get some aid for the area where the turbo is going to raise the pressure. I will also made a table for the valve control with axes of boost and speed. I have an idea to raise the boost a little at the high gear to get some extra for the trap speed. I bought a sensor for speed information. It goes to the place of the original speedometer cable connection at the 904.

I have also planned to made kind of launch control with the ecu (which supports that function) to see if I can get turbo spooling faster. It will just be a test and I dont think it is needed.

And I got the oil leak controlled with an electric vacuum pumpu. It is driven by the ecu making low vacuum at normal driving and deep vacuum when pulling hard. Simple table of rpm and boost level controls it.
Author:  Dart270 [ Sat Nov 11, 2023 4:48 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Sounds like great progress and great plans.

I have used a MSD 2-step for launch and it gets me about 0.1 or more sec in the 60 ft time vs. stalling up the converter to the same RPM. This is around 0.3 sec in the 1/4.

Lou
Author:  lgu32 [ Sat Dec 02, 2023 1:42 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
I have there now a proportional valve which is connected to the waste gate actuator line. I will try just keep the wastegate not activated at launch to get the boost raising a bit faster.

Another add on is the speed information on the ECU. I have planned to add extra boost with high gear starting at about 60 - 70 MPH. "Compensates bad aerodynamics".
Author:  Greg Ondayko [ Sat Dec 02, 2023 1:24 pm ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Good reports from finland.

Would the 4.10 ratio be too much gear for a turbo?

I would think that 3.73-3.23 would be better depending on boost pressures and torque converter stall?
Author:  lgu32 [ Sat Dec 02, 2023 8:32 pm ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Quote:
Good reports from finland.

Would the 4.10 ratio be too much gear for a turbo?

I would think that 3.73-3.23 would be better depending on boost pressures and torque converter stall?
Yes and no. It was too deep (mistake) for NA 225 which doesnt like to produce anything above 5000. I took this 4.1 because it was available when I had the replace the factory original 3.55 for noise and for sure grip installation. This really had 3.55 from new like I have had with another 170 car before.

I had plan to get my NA225 a little faster. But no. There was no power above 5000. Thats why I took 225 off and went to 170. And turbo.

With 4.10 and 245/60R14 I can cruise 50MPH @ 3000 rpm and do the full pull at 1/4 mile with above 100 MPH trap speed. I think this is just in balance of both worlds! But sure I am not going to use this car for summer cottage trips to the mid Finland. There is not available E85 which I need and need quite a lot of it.
Author:  lgu32 [ Tue Aug 06, 2024 2:19 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
I am planning a replacement cam for my boosted 170.

It has now 224/224 0.05 degrees and 110 LSA and I like to get the powerband about 500 rpm lower. That cam came from Oregon. This cam really starts at 3500 and the power is strong at redline of 6500. Not used daily at there.

One local grinder has a selection of old Mopar cam profiles. He has for example 218 (0.05) degrees cam profile with 0.45 lift.

I am thinking of a cam with 218/218/114 LSA. How does this sound for turbo experts?
Author:  Dart270 [ Tue Aug 06, 2024 7:09 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
That should get you down at least 500 RPM and it should still be great up high. I would even go 216 LSA and maybe 214 deg @ 0.050" for a street car, or 218/218 and 116 LSA sounds about perfect. Leighton Drake used quite small cams (like the MP 244/0.436" cam) and still made 500 HP on a 225. I am going to try the Howards cam 214/214 with 0.450" lift and 112 or 114 LSA on a 225. On a 170 you should go wider on the LSA. Kenny Duttweiler (famous turbo V6 guy and Bonneville authority) recommended 116 LSA for Bob Dally's 170 bcuda with turbo.

Lou
Author:  lgu32 [ Tue Aug 06, 2024 9:42 pm ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
Ok. I will check if he has 214 degree lobe model. We were discussing 218 (and 208) from which I was choosing the 218.

116 LSA sounds that special that I like to try it.

If I get a cam with 218/218/116 how should it be degreed in to the engine? Could you advise about this?
Author:  Dart270 [ Wed Aug 07, 2024 5:55 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
From my research, and from what I just measured on one of Leighton Drake's old turbo engines, I would most likely install it straight up (same intake centerline as the LSA number). I have installed my NA engine cams about 8 deg advanced of the LSA number, but turbos are different. I have not thought through this completely, but I would say either straight up or maybe 2-4 deg advanced from that. 218/218 and 116 should work well.

Lou
Author:  lgu32 [ Wed Aug 07, 2024 7:32 am ]
Post subject:  Re: From naturally aspirated 225 to a boosted 170
OK and thank you. I will ask to do such a cam.

It will take to next summer before I have results to reply. :D
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