Dyno testing results
06-11-19, 09:09 PM
#1
Rotary Enthusiast
Thread Starter
Dyno testing results
I thought I would share some stuff I tested on the Dyno.
it was a long and ungodly hot day so more work to be done on another day.
Gslse 13b.
Ported to maximum allowable for scca Street prepared(very little)
no 6 port actuators, they were reshaped.
rb long primary exhaust
50mm ida
Megasquirt efi
efihardware airbox.
the airbox gains were an average of 10hp vs no airbox. The power and torque curve is a smoother ramp with the box on. Pretty surprised at the result. The gain was across the entire rev range.
Going from 50mm trumpets to 90mm trumpets lowered my peak hp from 8200 to 7200 rpms. I am very happy with this result.
Downside is my torque curve tapers off about 1000 rpm earlier also so I'm tapering off at 6k instead of 7k.
I'm not sure how that earlier torque loss is going to affect track performance.
On my 6 port engine 26 degrees made .7 hp and .1 torque more than 22 degrees. I choose to stick with 22. It wasn't a noticable gain anywhere.
I have later plans to test afr differences. The little testing I did targeted 13.5 afr. I went to 13 afr in a couple areas that had flat spots or dips on the graph. 13 afr generally picked up 8 to 14 hp in those spots. I want to test 12 and 12.5. I'd planned on running wot at 12.5 for heat management and lube.
if i can pick up 10-12 hp everywhere by running richer I'll be doing that as a little worse fuel economy doesn't affect what I'm doing.
Last interesting thing. My rear injector has to be trimmed to add an extra 10% fuel across the board. Could be the injector or a multitude of other things. Anyways, it's worth adding a second wide band bung at the very least and swapping the wideband and comparing readings you get.
10% is approximately 1 afr so if your a street guy tuning cruise for 15, your unmonitored rotor may not be happy.
I have wide band and egt in each pipe. It's worth the money.
That's all folks
it was a long and ungodly hot day so more work to be done on another day.
Gslse 13b.
Ported to maximum allowable for scca Street prepared(very little)
no 6 port actuators, they were reshaped.
rb long primary exhaust
50mm ida
Megasquirt efi
efihardware airbox.
the airbox gains were an average of 10hp vs no airbox. The power and torque curve is a smoother ramp with the box on. Pretty surprised at the result. The gain was across the entire rev range.
Going from 50mm trumpets to 90mm trumpets lowered my peak hp from 8200 to 7200 rpms. I am very happy with this result.
Downside is my torque curve tapers off about 1000 rpm earlier also so I'm tapering off at 6k instead of 7k.
I'm not sure how that earlier torque loss is going to affect track performance.
On my 6 port engine 26 degrees made .7 hp and .1 torque more than 22 degrees. I choose to stick with 22. It wasn't a noticable gain anywhere.
I have later plans to test afr differences. The little testing I did targeted 13.5 afr. I went to 13 afr in a couple areas that had flat spots or dips on the graph. 13 afr generally picked up 8 to 14 hp in those spots. I want to test 12 and 12.5. I'd planned on running wot at 12.5 for heat management and lube.
if i can pick up 10-12 hp everywhere by running richer I'll be doing that as a little worse fuel economy doesn't affect what I'm doing.
Last interesting thing. My rear injector has to be trimmed to add an extra 10% fuel across the board. Could be the injector or a multitude of other things. Anyways, it's worth adding a second wide band bung at the very least and swapping the wideband and comparing readings you get.
10% is approximately 1 afr so if your a street guy tuning cruise for 15, your unmonitored rotor may not be happy.
I have wide band and egt in each pipe. It's worth the money.
That's all folks
06-12-19, 10:00 AM
#2
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,904
Received 2,646 Likes
on
1,874 Posts
interesting!
you made the right choice with timing, did you try 18-20 degrees too?
and yes try richer AFR's, after loosing a couple of piston engines because they were too lean, we usually try as lean as 13.2, and then set it up about 1/2 point richer, usually power doesn't change much.
you made the right choice with timing, did you try 18-20 degrees too?
and yes try richer AFR's, after loosing a couple of piston engines because they were too lean, we usually try as lean as 13.2, and then set it up about 1/2 point richer, usually power doesn't change much.
06-12-19, 03:52 PM
#3
Rotary Enthusiast
Thread Starter
The timing was the last thing of the day before I called it quits. Next time I'll try less timing. I also want to try more/ less in earlier rpms. If I recall correctly I'm at like 10 in the 1500 rpm range and a linear ramp to 22 at 3500 rpms.
Im thinking ill do 14, 18 and a 22 like a locked setup and just do short 5k rpm pulls. I should be able to pick timing for the 2-4k rpms based off if those passes.
It was a fun experience, in the past I was not nearly as involved in the process, I let an experienced tuner do it all. All i had to show was a Dyno chart. This time I did everything.
I got this cool Info to share and talk about plus a better understanding of how my engine reacts to changes. Measureable repeatable stuff instead if wild *** guesses.
Im thinking ill do 14, 18 and a 22 like a locked setup and just do short 5k rpm pulls. I should be able to pick timing for the 2-4k rpms based off if those passes.
It was a fun experience, in the past I was not nearly as involved in the process, I let an experienced tuner do it all. All i had to show was a Dyno chart. This time I did everything.
I got this cool Info to share and talk about plus a better understanding of how my engine reacts to changes. Measureable repeatable stuff instead if wild *** guesses.
06-13-19, 09:23 AM
#5
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,904
Received 2,646 Likes
on
1,874 Posts
The timing was the last thing of the day before I called it quits. Next time I'll try less timing. I also want to try more/ less in earlier rpms. If I recall correctly I'm at like 10 in the 1500 rpm range and a linear ramp to 22 at 3500 rpms.
Im thinking ill do 14, 18 and a 22 like a locked setup and just do short 5k rpm pulls. I should be able to pick timing for the 2-4k rpms based off if those passes.
Im thinking ill do 14, 18 and a 22 like a locked setup and just do short 5k rpm pulls. I should be able to pick timing for the 2-4k rpms based off if those passes.
i would get the AFR consistent first, set it to like 13:1 or something, and then try the timing.
it does help to know how your engine responds to fuel and or timing changes, when we ran PTE, we were only allowed 136rwhp, and the dyno they used to check us would read +/- 20rwhp! so we really needed to know how to change hp on the fly.
Thread
Thread Starter
Forum
Replies
Last Post
neit_jnf
3rd Generation Specific (1993-2002)
31
11-17-04 11:10 AM
Bambam7
2nd Generation Specific (1986-1992)
23
01-11-02 08:36 PM