Erik W. Treves
05-08-2023, 10:14 AM
It has been an interesting spring already - I am in the middle of parts collection and planning coordination for the BETA XT1 truck - while that doesn't completely keep me occupied - Idle hands...
My eyes turned to the Hawk Coupe and while we are approaching 10k on the car and it has been reasonably reliable (never left me on the side of road) - I have continued to refine the performance aspect of this car - trying to make it the "do everything car".
The drivability of the car was about 90% perfect - and sometimes it was 98% perfect but it would never stay that way on long highway cruise or long decel to an idle.... This winter I took a long look the charge pipe in front of the mass air and where I had my BOV. My twin turbo setup for the truck came with 2 BOV's and I only had 1.. so that got me thinking.. always dangerous.
The other thing that I have always wondered about is how I was merging the 2 turbo pipes immediately ahead of the MAF - Since building this car I would have never attempted this setup since the MAF normally needs a good 12 inches + ahead of it. But for what ever reason my car was working - well 90% of the time -
The issue I was wanting to fix is a hanging idle after decel - it would sit at 1300-1400 RPM at times and when it was cold out my initial start was "untuned" sounding.
In the middle of all this I bought new RT 660 Falken tires and reset the rebound of the Koni Reds in hope of lowering my times at the local track.
So the weekend before the first event I added a second BOV to my intake track which caused me to replace my merge pipe.... and that's where things went COMPLETELY off track.!!!!
Merge pipe before...
https://thefactoryfiveforum.com/attachment.php?attachmentid=184193&d=1683557532
and after...
https://thefactoryfiveforum.com/attachment.php?attachmentid=184194&d=1683557532
keep in mind the MAF is basically right after this 4inch collector - there is a 45* silicone elbow but that's it... anyway I installed this "upgrade" and all of the sudden the car was idling great! best it ever has! I thought it was good to go - ha! Took it took work a couple of days later and the car was way down on power and had all sorts of issues making a clean pass - and was slow to accept throttle... I plugged in the laptop and my AFR's were WAY LEAN - not sure how the car even ran that way... anyway I tried to tune around it and the car just got worse and worse - so it had to be mechanical in the ENGINE>!>!>
Well after a long night I determined that all the compression was good and all the plugs and coils were also good - -- whew.
Spoke to Wayne Presley and decided to return the car to NA and see how the car reacted - to my surprise ran AWESOME (low on power) - but perfect! I went ahead and tuned for NA again - at which time my fuel pump locked up and died.... in the subdivision thankfully....
so it appears I had 2 things going on - bad intake charge pipe design and a failing fuel pump - only took 2 weeks to find - but once it breaks hard things get simple....lol...but I never get there in the shorted path.
now the issue was how do I change the current setup to be able to get a 12+ inch straight run in front of the MAF - I mean I ended up in this design cause there was no room! (and I built the car in 4 months)..... well after laying 4 inch pipe all over the engine compartment this how it went - on a completed car that has been on the road for 4 + years.... it never ends does it??
https://thefactoryfiveforum.com/attachment.php?attachmentid=184195&d=1683557532
https://thefactoryfiveforum.com/attachment.php?attachmentid=184196&d=1683557532
And here is the final product that we raced with this weekend - 2x BOV's now between the turbo and intercooler seems to keep the intercooler from getting heat soaked as well....
https://thefactoryfiveforum.com/attachment.php?attachmentid=184202&d=1683558765
My eyes turned to the Hawk Coupe and while we are approaching 10k on the car and it has been reasonably reliable (never left me on the side of road) - I have continued to refine the performance aspect of this car - trying to make it the "do everything car".
The drivability of the car was about 90% perfect - and sometimes it was 98% perfect but it would never stay that way on long highway cruise or long decel to an idle.... This winter I took a long look the charge pipe in front of the mass air and where I had my BOV. My twin turbo setup for the truck came with 2 BOV's and I only had 1.. so that got me thinking.. always dangerous.
The other thing that I have always wondered about is how I was merging the 2 turbo pipes immediately ahead of the MAF - Since building this car I would have never attempted this setup since the MAF normally needs a good 12 inches + ahead of it. But for what ever reason my car was working - well 90% of the time -
The issue I was wanting to fix is a hanging idle after decel - it would sit at 1300-1400 RPM at times and when it was cold out my initial start was "untuned" sounding.
In the middle of all this I bought new RT 660 Falken tires and reset the rebound of the Koni Reds in hope of lowering my times at the local track.
So the weekend before the first event I added a second BOV to my intake track which caused me to replace my merge pipe.... and that's where things went COMPLETELY off track.!!!!
Merge pipe before...
https://thefactoryfiveforum.com/attachment.php?attachmentid=184193&d=1683557532
and after...
https://thefactoryfiveforum.com/attachment.php?attachmentid=184194&d=1683557532
keep in mind the MAF is basically right after this 4inch collector - there is a 45* silicone elbow but that's it... anyway I installed this "upgrade" and all of the sudden the car was idling great! best it ever has! I thought it was good to go - ha! Took it took work a couple of days later and the car was way down on power and had all sorts of issues making a clean pass - and was slow to accept throttle... I plugged in the laptop and my AFR's were WAY LEAN - not sure how the car even ran that way... anyway I tried to tune around it and the car just got worse and worse - so it had to be mechanical in the ENGINE>!>!>
Well after a long night I determined that all the compression was good and all the plugs and coils were also good - -- whew.
Spoke to Wayne Presley and decided to return the car to NA and see how the car reacted - to my surprise ran AWESOME (low on power) - but perfect! I went ahead and tuned for NA again - at which time my fuel pump locked up and died.... in the subdivision thankfully....
so it appears I had 2 things going on - bad intake charge pipe design and a failing fuel pump - only took 2 weeks to find - but once it breaks hard things get simple....lol...but I never get there in the shorted path.
now the issue was how do I change the current setup to be able to get a 12+ inch straight run in front of the MAF - I mean I ended up in this design cause there was no room! (and I built the car in 4 months)..... well after laying 4 inch pipe all over the engine compartment this how it went - on a completed car that has been on the road for 4 + years.... it never ends does it??
https://thefactoryfiveforum.com/attachment.php?attachmentid=184195&d=1683557532
https://thefactoryfiveforum.com/attachment.php?attachmentid=184196&d=1683557532
And here is the final product that we raced with this weekend - 2x BOV's now between the turbo and intercooler seems to keep the intercooler from getting heat soaked as well....
https://thefactoryfiveforum.com/attachment.php?attachmentid=184202&d=1683558765