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| My 1988 LFX F40 build. (Page 30/68) |
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ericjon262
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MAR 04, 11:10 PM
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| quote | Originally posted by Daryl M:
Doesn't running a turbo defeat the purpose of headers? Besides, most cars are still naturally aspirated. |
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kinda, but kinda not, pulse tuning can make improvements in the gas signal to the turbine wheel, which results in a faster spool, the flip side, is that the added length of tubing creates more surface area for heat transfer to occur, so unless steps are taken to reduce the thermal conductivity of the pipe (wrap, coatings ect) then the gains could be less than expected. this is part of the reason I went with a log manifold for the turbo kit I am currently building, but the main part is that it is mush simpler, and easier to build, and in my case I don't think the gains would be worth the effort.
All that being said, I would be very interested in seeing back to back dyno pulls, changing only the manifolds and tune to test the performance difference between a well designed log, and a well designed header on a turbo car. ------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html
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fieroguru
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MAR 05, 10:42 AM
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| quote | Originally posted by ericjon262:
All that being said, I would be very interested in seeing back to back dyno pulls, changing only the manifolds and tune to test the performance difference between a well designed log, and a well designed header on a turbo car.
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Different engine but interesting results.
https://www.enginelabs.com/...ubular-race-headers/
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Will
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MAR 05, 10:58 AM
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| quote | Originally posted by wftb:
The new integrated exhaust manifolds are largely the result of designing an engine from the get go to be more efficient with turbos.Get the turbo as close as possible to the combustion chamber to better make use of the heat and pressure there and then bolt the catylitic converter right to the turbo and you can lower cold start emisions. New turbo v8's from BMW, Mercedes and some others use 2 small turbos where the intake used to be in a conventional V8-in the middle of the V. I am thinking they do not do this with V6's as there might not be enough room in the V.
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And on the non-turbo versions, they can bolt the catalyst straight to the head.
Combustion efficiency in modern engines is >99%. That is, >99% of fuel introduced into the chamber is burned. It's now essentially impossible to reduce unburned hydrocarbons by improving combustion efficiency. Thus the focus for emissions reduction is on quickening catalyst lightoff. Seconds count in that area.
| quote | Originally posted by ericjon262:
kinda, but kinda not, pulse tuning can make improvements in the gas signal to the turbine wheel, which results in a faster spool, the flip side, is that the added length of tubing creates more surface area for heat transfer to occur, so unless steps are taken to reduce the thermal conductivity of the pipe (wrap, coatings ect) then the gains could be less than expected. this is part of the reason I went with a log manifold for the turbo kit I am currently building, but the main part is that it is mush simpler, and easier to build, and in my case I don't think the gains would be worth the effort.
All that being said, I would be very interested in seeing back to back dyno pulls, changing only the manifolds and tune to test the performance difference between a well designed log, and a well designed header on a turbo car.
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A well designed header won't fit in the same space as a well designed log, so things can only be so comparable. Headers in turbo race cars trade pressure at the exhaust valve for velocity at the turbine inducer for very efficient transfer of angular momentum to the turbine while keeping exhaust back pressure minimal. This is key to operating the turbo beyond crossover, but it does not package well.[This message has been edited by Will (edited 03-05-2020).]
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Will
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MAR 05, 01:36 PM
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Interesting that they put in a plug for Holley EFI, then use a manual boost controller. What kind of knuckle dragger shenanigans is that? They might as well have put a Q-Jet on it.
Interesting that they *almost* achieved crossover at the control point, even on a fairly primitive "race" system and a low boost pressure. 180 degree collectors would have done even better.
The "race" system DID hit crossover briefly in the mid-range RPM, where it hit 12 psi boost with 11.5 psi of back pressure @ 4800 RPM.
750 HP looks SOOOOOOO easy.
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ericjon262
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MAR 06, 12:11 AM
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I'd like to see the difference on an even fire V6 with equal length runners, I think the difference might even favor a well designed log in some aspects. as far as packaging goes, I think both could be done on my car, in the allotted space, but I'm not going to do something that involved yet, I have too many other irons in the fire. ------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html
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RandomTask
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MAR 30, 08:53 PM
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Daryl,
Random question - Do you know where you can get the FW bolts? I cant find them online to save my life.
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Daryl M
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MAR 30, 11:31 PM
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I might if I knew what you meant by "FW Bolt". What is it you need?
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Will
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MAR 31, 12:07 PM
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I @$$ume he means flywheel bolts...
I just found out that the forged crank Northstars use 11mm flywheel bolts like the LS engines.
ARP makes 3 or 4 different lengths of 11mm FW bolts.
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Daryl M
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MAR 31, 06:07 PM
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I went to a local industrial bolt place and bought exactly what I needed. They did have to special order them, but they had them delivered directly to me.
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RandomTask
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APR 03, 07:55 PM
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Thanks. I ended up ordering them from fastenal. They were M10-1.0 and I got them in 25mm length for my flywheel.
Next up, figuring out what the hell this piece is that came with the clutch kit...
 [This message has been edited by RandomTask (edited 04-03-2020).]
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