Dyno Tuning of SRL 0427
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- Alvin
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Dyno Tuning of SRL 0427
We had the opportunity to dyno tune Brian's (Bkippen) '67 2000 earlier this week.
Brian's build thread of #427 is here:
http://www.311s.org/phpBB3/viewtopic.ph ... 7&start=30
After he completed the "gentle" break-in of his Hasselgren-built U20 with a thousands-of-miles roadtrip he wanted to have it tuned. He also wanted to test different Solex filter housings.
The U20 has a C cam, .040 pistons, 44 Mikunis, a lovely JT68 exhaust system and 9:5:1 compression on 91 octane:
On the dyno:
You can hear the Solex-U20 sing in this video below. Keep watching as Brian took videos comparing the open vs late elements...it's ALOT louder with the early style:
[youtube][/youtube]
And, the magic numbers...Brian baselined at 121hp/122tq and left with 142hp/134tq to the wheels:
Very nice power delivery! And a great example of how tuning is critical
Thanks Brian, your roadster is immaculate...and fast!
More pictures here:
http://www.zcarblog.com/2017/12/08/perf ... -2000.html
Alvin Gogineni
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
Instagram
YouTube
My SR20 Build Thread
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
YouTube
My SR20 Build Thread
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Re: Dyno Tuning of SRL 0427
Thanks for the write up Alvin! A nifty note. Changing from the late comp housing to the early open housing increased the hp by 7. The remaining 14 horsepower was obtained primarily by using the 123ignition and a final icing was a slightly larger main fuel jet.
Brian
Berkeley, CA
1967 1600
1967.5 2000
1966 PL411
1967 Nissan Patrol
1970 240z
1972 240z
another 1972 240z
2013 Tacoma
Berkeley, CA
1967 1600
1967.5 2000
1966 PL411
1967 Nissan Patrol
1970 240z
1972 240z
another 1972 240z
2013 Tacoma
- spags1986
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Re: Dyno Tuning of SRL 0427
I can listen to that sound all day! Beautiful car bkippen, and thanks for the write up Alvin.
1967.5 2000 (In Frame off restoration)
1966 1600
1969 2000
1966 1600
1969 2000
- cole455
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Re: Dyno Tuning of SRL 0427
Oh wow, thanks! Very cool..
Awesome to see a comparison with different air filter housings! Would be interesting to see a similar test done with different length velocity stacks as well... Anyone?
Awesome to see a comparison with different air filter housings! Would be interesting to see a similar test done with different length velocity stacks as well... Anyone?
- GeoffM
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Re: Dyno Tuning of SRL 0427
Great post...thanks for sharing! The car looks awesome.
Nice to have empirical numbers.
Nice to have empirical numbers.
Geoff
1969 SPL-311
1969 SPL-311
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Re: Dyno Tuning of SRL 0427
Dang, I might have to source an early filter housing!
J. Baker
Lafayette, CA
'69 2000 (Solex)
Lafayette, CA
'69 2000 (Solex)
- Gregs672000
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Re: Dyno Tuning of SRL 0427
Stunner of a car, great engine result, so fun when the tuning improves things so nicely! Very interesting that the housing makes that much difference. Was he using a different backing plate as well, or just the front cover? The original had built in velocity stacks, and they can make some flow improvements. If it were just the front cover, that is quite significant as well. If so, I wonder how it would respond to additional holes being drilled in it as some have done. It has been my understanding that Nissan was trying to make the intake more quiet, but if it costs power, well that's a no go!
What did you finally come to for an ignition curve? It looks like she might have miss-fired at about 5000 rpms as that torque was doing great then dropped suddenly for a bit, then recovered and even increased. Were you running more or less advance above 5000 vs your original timing? She really spikes up nicely at 5200. I see you had 7 recorded pulls; did you print out the others, noting what changes you were making and the result (I would assume so, as you know the intake was worth 7, timing worth 14 etc). What was changed first, intake or timing (I would assume timing, but of course everything works as a system). 21hp/12tq change, that's freakin great, well worth the dyno time cost!
I'm sure others will be interested in your final jetting too. Assuming 37mm chokes?
Congrats on a GREAT car and build!
What did you finally come to for an ignition curve? It looks like she might have miss-fired at about 5000 rpms as that torque was doing great then dropped suddenly for a bit, then recovered and even increased. Were you running more or less advance above 5000 vs your original timing? She really spikes up nicely at 5200. I see you had 7 recorded pulls; did you print out the others, noting what changes you were making and the result (I would assume so, as you know the intake was worth 7, timing worth 14 etc). What was changed first, intake or timing (I would assume timing, but of course everything works as a system). 21hp/12tq change, that's freakin great, well worth the dyno time cost!
I'm sure others will be interested in your final jetting too. Assuming 37mm chokes?
Congrats on a GREAT car and build!
Greg Burrows
'67 2000 #588
Tacoma, WA
'67 2000 #588
Tacoma, WA
- Pjackb
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Re: Dyno Tuning of SRL 0427
Thanks for sharing I was wondering were you got the increase from,bkippen wrote:Thanks for the write up Alvin! A nifty note. Changing from the late comp housing to the early open housing increased the hp by 7. The remaining 14 horsepower was obtained primarily by using the 123ignition and a final icing was a slightly larger main fuel jet.
And congratulations on a beautiful example of Roadster
- sfdaugherty
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Re: Dyno Tuning of SRL 0427
Very impressive numbers for a 50 year old 2L. A little better than my stock SR20DE S14 and only 18 hp and 7 lbft of torque less than my SR20DE S15 Autech with 11.7 to 1 compression.
Well done.
Shannon
Well done.
Shannon
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
- Mattk
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Re: Dyno Tuning of SRL 0427
Quite the the roadster!! Sounds great! Must be fun to take through and around Tilden Park!
Cheers
Matthew
Cheers
Matthew
MattK
- Alvin
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Re: Dyno Tuning of SRL 0427
Shannon,sfdaugherty wrote:Very impressive numbers for a 50 year old 2L. A little better than my stock SR20DE S14 and only 18 hp and 7 lbft of torque less than my SR20DE S15 Autech with 11.7 to 1 compression.
Well done.
Shannon
We dyno tuned our friend's Autech SR20-powered Miata just before JCCS. This was built by Spriso and Eric Straw:
With a few adjustments, it made 179hp/149tq at the wheels, on 91 octane. I thought she was quick when Diamond gave me a ride back in August, but now it must absolutely rip!
[youtube][/youtube]
Last edited by Alvin on Fri Dec 08, 2017 4:15 pm, edited 1 time in total.
Alvin Gogineni
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
Instagram
YouTube
My SR20 Build Thread
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
YouTube
My SR20 Build Thread
- Alvin
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Re: Dyno Tuning of SRL 0427
PREACHGeoffM wrote: Nice to have empirical numbers.
Alvin Gogineni
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
Instagram
YouTube
My SR20 Build Thread
San Jose, CA
1967.5 SPL/SR20
1997 Acura Integra GS-R
2022 Chevy Bolt EUV
zcarblog.com
YouTube
My SR20 Build Thread
- sfdaugherty
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Re: Dyno Tuning of SRL 0427
Alvin:With a few adjustments, it made 179hp/149tq at the wheels, on 91 octane. I thought she was quick when Diamond gave me a ride back in August, but now it must absolutely rip
Nice to have something to compare.
Mine only put out 160hp and 139tq (also on 91 octane). The main difference is probably that he can run that beautiful factory stainless steel header. Other differences might be the altitude (6000ft) and the dyno. I would think that dynos would compensate for altitude but I’m no expert.
Fun fact: it put out 165hp when the k&n air filter was removed.
Shannon
You do not have the required permissions to view the files attached to this post.
69 2000 SRL311-10088 (Type 4 Solexes)
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
68 SR20DE SPL311-18735 (SR20DE S15 Autech)
68 2000 SRL311-01179 (Restoration underway)
68 1600 SPL311-20462 SOLD! After 41 years in the family
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Re: Dyno Tuning of SRL 0427
bakerjf wrote:Dang, I might have to source an early filter housing!
Pretty sure Brian's got my repro early AF assembly with 2" K&N and included velocity stacks too. Also the light steel FW and 225mm clutch yow!
We have another filter element to test too, but thats for another day/another thread. U20, the quintessential roadster engine.
Nice work guys!
LT/JT
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Re: Dyno Tuning of SRL 0427
I do have the Jim special air box.
The sag Greg mentioned is likely due to timing. We ran several runs and adjusted the curve. If I had an entire day at Z car garage and plumbing for a vacuum signal I’m sure we could steady it and likely increase output by a couple hp.
Here is my timing curve. A note is I am running 17degrees static so the numbers you see are 17deg plus the programmed number.
I am still selling these distributors too.
The sag Greg mentioned is likely due to timing. We ran several runs and adjusted the curve. If I had an entire day at Z car garage and plumbing for a vacuum signal I’m sure we could steady it and likely increase output by a couple hp.
Here is my timing curve. A note is I am running 17degrees static so the numbers you see are 17deg plus the programmed number.
I am still selling these distributors too.
You do not have the required permissions to view the files attached to this post.
Brian
Berkeley, CA
1967 1600
1967.5 2000
1966 PL411
1967 Nissan Patrol
1970 240z
1972 240z
another 1972 240z
2013 Tacoma
Berkeley, CA
1967 1600
1967.5 2000
1966 PL411
1967 Nissan Patrol
1970 240z
1972 240z
another 1972 240z
2013 Tacoma