Dyno sheet thread

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sfdaugherty
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Re: Dyno sheet thread

Post by sfdaugherty » Fri May 03, 2019 6:09 pm

Dyno results for my sr20de s15 Autech. Factory high lift cam and 11.7 to 1 compression ratio. The video is of an earlier run. 161 hp and 139 ft lbs of torque.
S15 dyno 161 hp 139 tq(1).jpg
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Shannon
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Last edited by sfdaugherty on Sat May 04, 2019 10:17 pm, edited 1 time in total.
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Waiting patiently for restoration)
69 2000 SRL311-10485 (1/2 owner) (Type 2 Solexes)
68 1600 SPL311-20462 SOLD! After 41 years in the family

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Pjackb
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Re: Dyno sheet thread

Post by Pjackb » Sat May 04, 2019 7:06 am

sfdaugherty wrote:
Fri May 03, 2019 6:09 pm
Dyno results for my sr20de s15 Autech. Factory high lift cam and 11.7 to 1 compression ratio. The video is of an earlier run. 161 hp and 139 lb ft of torque.
Shannon
This is stock Autech right ?

GoldHawg
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Re: Dyno sheet thread

Post by GoldHawg » Sat May 04, 2019 7:09 am

[/quote] This is stock Autech right ? [/quote]

Sans header. Wonder what it would do with a nice SS header? Hmmm. May have to solve that problem real soon. Yes Shannon, real soon!

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sfdaugherty
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Re: Dyno sheet thread

Post by sfdaugherty » Sat May 04, 2019 8:42 am

Yes. Stock except converted distributor to coil on plug and tuned with Haltech Platinum Pro ecu.

The factory stainless header won't fit in a roadster so anxiously awaiting a header from Jeff.

Shannon
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Waiting patiently for restoration)
69 2000 SRL311-10485 (1/2 owner) (Type 2 Solexes)
68 1600 SPL311-20462 SOLD! After 41 years in the family

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Gregs672000
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Re: Dyno sheet thread

Post by Gregs672000 » Sat May 04, 2019 12:44 pm

Very nice numbers for sure. I did some comparisons in torque between a few of the U20 sheets, noting where peak torque occurred. I think Brian's sheet demonstrates how a cam, carb jetting and timing (ignition and cam) all work together when it hits it's 'sweet spot'. The torque REALLY picks up between 4000 and 4500 rpms on Brian's motor, jumping about 17 points in this very short span, where as the other U20 profiles have remained close to their peeks. This could be where the C cam outperforms the B when all the other components are aligned (?). It also shows how the C or the " bigger" (more duration) cam hurts low end power even vs the B, as Brian's engine is making 11 less ft lbs of torque at 3500 rpms vs the others. By 4000 rpms they are equal and very suddenly the cam "comes on" and the power increase results. I wonder what an A cam SU engine would make and what the profile would look like in comparison. I would also be interested in what they did during the tuning that resulted in such a significant change in Brian's output... really a big change!

Comparing Brian's U20 to the S15 (variable cam timing Engine? Also much higher compression ratio), at 3500 the S15 has a lot more torque (19 ft Lbs more), but when the C cam comes on, they become about equal. But unlike the U20, which starts dropping off past 5000 rpms, the S15 continues to build torque all the way to 5500 rpm and maintains. Is all this the result of variable cam timing? You see how engineers have been able to "have your cake and eat it too" eh? Can't fight 40 years of technology!

I'm just spit balling here, but I think Brian's motor has come together very nicely regarding cam timing. I wonder how the other two B cam motors might benefit from some cam timing adjustment and likely subsequent tuning changes? Very helpful that all these engines were run on the same dyno. This is great information for one to do some general comparisons, thanks!

Discuss... :D
Greg Burrows
'67 2000 #588
Tacoma, WA