84 Corvette Journey
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Unfortunately I don't remember which one is in mine right now, maybe Bosch? I've had a few different ones over the years. There is a good app called Snag-It that does a great job capturing things you can even do an instructional vid with it. It isn't free, but not that pricey either. There shouldn't be an issue capturing TP table screens anyway.
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
I was planing on using a WB controller that can simulate NB for the BLM and INT but I have heard they are too slow. What are people’s thoughts and experiences with using the WB to do NB as well?
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
Wbo2
Ok
I have now installed a LC-2 wide band O2 sensor and it has made a big difference. The EBL Flash II ECM can learn the VE table values but you really need a wide band O2 sensor to do it. I tried with the Narrow Band and spent a bit of time smoothing the values but the tuning wasn’t that good.
All the advice I got was to install a WB (thanks Buccaneer and others). I didn’t really want to but I came to realize that it was mandatory to get a decent tune.
I forced the ECM into open loop operation by setting the closed loop CTS threshold to 150 Deg C and then did about six consecutive VE learns. The car is running very well now. I plane on doing some dyno runs in the near future so I will keep you all posted. Also whilst no two engines are the same, if anyone has a similar set up and would like my table values just PM me and I’m share what I have. I expect I will be able to make even more advances on the dyno.
I have now installed a LC-2 wide band O2 sensor and it has made a big difference. The EBL Flash II ECM can learn the VE table values but you really need a wide band O2 sensor to do it. I tried with the Narrow Band and spent a bit of time smoothing the values but the tuning wasn’t that good.
All the advice I got was to install a WB (thanks Buccaneer and others). I didn’t really want to but I came to realize that it was mandatory to get a decent tune.
I forced the ECM into open loop operation by setting the closed loop CTS threshold to 150 Deg C and then did about six consecutive VE learns. The car is running very well now. I plane on doing some dyno runs in the near future so I will keep you all posted. Also whilst no two engines are the same, if anyone has a similar set up and would like my table values just PM me and I’m share what I have. I expect I will be able to make even more advances on the dyno.
Last edited by GregMartin; Jul 10, 2019 at 08:31 AM.
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Nice! That WB makes all the difference in the world when trying to tune and saves a lot of time. 
I can't wait to hear from you about the dyno pulls on Ben's dyno. 
I can't wait to hear from you about the dyno pulls on Ben's dyno.
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
Dyno Pulls
Hi Tom
Yes I did some dyno runs on my friends Dyno Dynamics eddy current dyno yesterday. These dynos are referred to as heartbreakers and this one didn’t disappoint.
The peak power was 210hp at around 5000rpm on the rear wheels. So if you multiple it by 15% that’s probably what you would read on an inertia dyno. If you then multiple that by 16% for the 4+3 drive train you get about 275-280hp which is about what I would expect with standard injectors and throttle bodies.
We then went for a bit of a road test and the tuner said he thought the car was good for about mid 13s quarters which seams about right. He also said it was much better than a stock L98 but that’s not that surprising really.
Peak HP wasn’t really the aim of the day, we spent most of the time looking at AF ratios at different loads. That’s the benefit of a eddy current dyno.
Big thank you to ben73 for giving up your time and all your help yesterday.
Yes I did some dyno runs on my friends Dyno Dynamics eddy current dyno yesterday. These dynos are referred to as heartbreakers and this one didn’t disappoint.
The peak power was 210hp at around 5000rpm on the rear wheels. So if you multiple it by 15% that’s probably what you would read on an inertia dyno. If you then multiple that by 16% for the 4+3 drive train you get about 275-280hp which is about what I would expect with standard injectors and throttle bodies.
We then went for a bit of a road test and the tuner said he thought the car was good for about mid 13s quarters which seams about right. He also said it was much better than a stock L98 but that’s not that surprising really.
Peak HP wasn’t really the aim of the day, we spent most of the time looking at AF ratios at different loads. That’s the benefit of a eddy current dyno.
Big thank you to ben73 for giving up your time and all your help yesterday.
Intermediate
Joined: Jun 2016
Posts: 42
Likes: 33
From: Houston area
My 84
Just read your posts. Brilliant journey. I've got an 84 that had seen some various mods and a CFI car can certainly run hard. Pop the hood after a 13 flat at 107 and watch the eyes bug out lol
Enjoyed the read, lots of the same guys provided my answers a few years back.
Awesome ride !
Last edited by racerxl83; Aug 15, 2019 at 12:48 AM.
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Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
My 84
Just read your posts. Brilliant journey. I've got an 84 that had seen some various mods and a CFI car can certainly run hard. Pop the hood after a 13 flat at 107 and watch the eyes bug out lol
Enjoyed the read, lots of the same guys provided my answers a few years back.
Awesome ride !
I'm glad you enjoyed the posts I thought it would be helpful to others with crossfire Corvettes. They are a little different so there isn’t as much info out there, but as you say you can make them go pretty hard. The guy that helped me with the dyno ben73 has a 84 that runs 12 flat with a crossfire. Buccaneer thinks it’s the fastest normally aspirated crossfire in the world. By all accounts it’s a monster.
I was pretty conservative with my build but I can probably find a bit more HP if I go looking.
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Hi Tom
Yes I did some dyno runs on my friends Dyno Dynamics eddy current dyno yesterday. These dynos are referred to as heartbreakers and this one didn’t disappoint.
The peak power was 210hp at around 5000rpm on the rear wheels. So if you multiple it by 15% that’s probably what you would read on an inertia dyno. If you then multiple that by 16% for the 4+3 drive train you get about 275-280hp which is about what I would expect with standard injectors and throttle bodies.
We then went for a bit of a road test and the tuner said he thought the car was good for about mid 13s quarters which seams about right. He also said it was much better than a stock L98 but that’s not that surprising really.
Peak HP wasn’t really the aim of the day, we spent most of the time looking at AF ratios at different loads. That’s the benefit of a eddy current dyno.
Big thank you to ben73 for giving up your time and all your help yesterday.
Yes I did some dyno runs on my friends Dyno Dynamics eddy current dyno yesterday. These dynos are referred to as heartbreakers and this one didn’t disappoint.
The peak power was 210hp at around 5000rpm on the rear wheels. So if you multiple it by 15% that’s probably what you would read on an inertia dyno. If you then multiple that by 16% for the 4+3 drive train you get about 275-280hp which is about what I would expect with standard injectors and throttle bodies.
We then went for a bit of a road test and the tuner said he thought the car was good for about mid 13s quarters which seams about right. He also said it was much better than a stock L98 but that’s not that surprising really.
Peak HP wasn’t really the aim of the day, we spent most of the time looking at AF ratios at different loads. That’s the benefit of a eddy current dyno.
Big thank you to ben73 for giving up your time and all your help yesterday.
Good to hear about the progress you have made and I'm sure with a bit more tweaking you will get some more out of it for sure. Thanks again Greg.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
But I might just drive it for a while. It’s sharp on the throttle and a lot of fun. It’s also well behaved which is important for a daily driver.
Last edited by GregMartin; Aug 15, 2019 at 05:59 PM.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
No not staving for just fuel. We spent a lot of time with the AF trace scaled up and altered power enrichment to make the best power. (Plenty if head room and we could make it too rich and loose power). The peak is quite flat over a fairly large range. I think it is starving though. The standard throttle bodies only move about 570cfm and a good number for a 350 has always been 750cfm. I’ve seen power traces like this before when the carby is too small. I think it needs more air and more fuel.
But I might just drive it for a while. It’s sharp on the throttle and a lot of fun. It’s also well behaved which is important for a daily driver.
But I might just drive it for a while. It’s sharp on the throttle and a lot of fun. It’s also well behaved which is important for a daily driver.
Why don't you look at your MAP readings on a scan tool during at WOT pull? If the TB's are in fact too small (and I really don't think that they are), then you will see vacuum build with RPM.
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
I don't know....that (the bold) sounds exactly like my 400 CFI was when it was too lean. Felt wicked...ran great....ran 15's at the track.
Why don't you look at your MAP readings on a scan tool during at WOT pull? If the TB's are in fact too small (and I really don't think that they are), then you will see vacuum build with RPM.
Why don't you look at your MAP readings on a scan tool during at WOT pull? If the TB's are in fact too small (and I really don't think that they are), then you will see vacuum build with RPM.
So that is consistent with what we were seeing on the dyno.
But wow I just noticed that I reved it to 5925 on one of these runs. That can’t be good for the bearings. I don’t imagine the engine has ever spun that fast in its life. I think it’s time to rev limit it before I do something bad.
Last edited by GregMartin; Aug 16, 2019 at 08:41 AM.
Le Mans Master
Joined: Aug 2017
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From: New Jersey
Disappointingly I forgot to data log the dyno pulls but I just checked some logs from a couple of WOT street runs. @ WOT and low rpm say below 2500 KPA is 100 or 101 as expected. Over 3000 it starts to drop. @ 4000 RPM KPA is 96. @ 4900 KPA is 94 . It hovered around 93 to 95 KPA up to 5500 RPM on every run.
So that is consistent with what we were seeing on the dyno.
But wow I just noticed that I reved it to 5925 on one of this runs. That can’t be good for the bearings. I don’t imagine the engine has ever spun that fast in its life. I think it’s time to rev limit it before I do something bad.
So that is consistent with what we were seeing on the dyno.
But wow I just noticed that I reved it to 5925 on one of this runs. That can’t be good for the bearings. I don’t imagine the engine has ever spun that fast in its life. I think it’s time to rev limit it before I do something bad.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
I agree with 84 4+3; engine should be able to go to 6k no problem. That's part of the reason for the heads/intake/exhaust, was to get more RPM!
Le Mans Master
Joined: Aug 2017
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From: New Jersey
Age has nothing to do with it. If it's been maintained you're fine. Metal isn't like plastic where it gets brittle over time... well it does but not in the same way. If it's not making power up there it's not worth spinning it that high but you didn't hurt anything. Now if it were 6900, this would be a different story.
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
Thread Starter
Drifting
Joined: Jun 2018
Posts: 1,402
Likes: 287
From: Brisbane Australia
C4 of Year Finalist (performance mods) 2019
Age has nothing to do with it. If it's been maintained you're fine. Metal isn't like plastic where it gets brittle over time... well it does but not in the same way. If it's not making power up there it's not worth spinning it that high but you didn't hurt anything. Now if it were 6900, this would be a different story.
I think discretion is the better part of valor in this case.