Go Back  CorvetteForum - Chevrolet Corvette Forum Discussion > Off Topic > Other Cars
Reload this Page >

5.3 4l80e 240sx < 3000lbs College budget

Other Cars Non-Corvette Content, Daily Drivers, Winter Beaters, Work Trucks, Tow Vehicles, for sale

5.3 4l80e 240sx < 3000lbs College budget

Old 08-22-2018, 11:04 PM
CF Senior Member
Thread Starter
Kingtal0n's Avatar
Member Since: Oct 2007
Location: miami florida
Posts: 876
Thanked 76 Times in 60 Posts

Semester started today for me, Advanced strength of materials, adv control systems, all kinds of fun to focus on. So the last two weeks I finally had some real spare time to get some things done I've been wanting to do. But not too much

One of the things i did was connect the wideband to the HPtuners scanner, so I can log the a/f ratio while driving and go back to check it later. The way I've BEEN tuning is basically by driving the car and then trying to remember where it was lean or rich (I'm pretty good at that) but my lazy method is no match to actually logging the wideband accurately then reviewing the situation painstakingly for hours making minute changes to fine tune the engine.

Key word here is 'fine tune' and HPtuners 2-bar OS does not support real-time mapping which makes it difficult to remember where the engine was lean or rich 20 minutes later sitting inside at a table and then re-upload the map. On the other hand the result is often superior when using data-logging when instruments are logging how you think they are in specific frames. No sense wasting 10-15 hours reviewing logs and making changes if your just going to change injectors or something the next day or if the logs don't have data presented the way you need it. So while I still technically need a cam, I might not cam this engine, I think I want something lighter or smaller. For now,I can't just wait around forever and not tune it till I decide to change the cam or not; I decided to knock this out while i had the time, get over the lack of real time tuning and spend the time to dial it in the only other way that makes any sense.

So here is my original map I've been driving on for months and months "un-tuned". this is the first log more or less I took with the hptuners scanner. I tuned it this way be "feel".
It was fairly close but definitely needed fine tuning. I was being a bit too conservative with fuel, it wasn't knocking or anything but it definitely picked up a bunch of torque and responseright through the mid-range with the extra fuel, it seems to run great between 12.8 to 13.0 approaching 0psi. The knock sensors do work and from time to time they did help me remove 3 to 5 degrees from some of the mid-load regions of the map where it had 25* or something and really needed more like 20*.

Now here is it after a day or two of fine tuning, still not done but much more well tuned

Here are the changes I made to the VE map in order to 'fine tune' the engine

Now that is some fine tuning. Here is the VE map before and after as well:

After fine tuning for ~1 day:

And even more fine tuning later....

In an effort to boost the voltage at the battery and in the car I also changed my alternator and made a small shield for it, and upgraded the wire for it.

Finally in order to fine tune, or rather what kick started my fine tuning, was the addition of an IAT sensor and appropriate shielding for the intake tube:

I added a couple shields. I will show more shielding once I get a little more of that done also. I just like to finalize some things before I start showing them. Like that silly radiator tap for the steam port; it needs to be a welded fitting ideally. But I need to replace the radiator anyways because the orange water coming out of the truck engine is disgusting inside it. I've been flushing it monthly until it turns back to normal color, then I'll buy a new radiator and do the radiator shroud, hold-down/core support cover, final radiator duct work and overflow container all at once. It will be marvelous haha.

I can't wait to color that intake pipe by the way. The right way, probably real powder coat. But to do that I need to park the car for a couple days and I just can't bring myself to stop driving it... >
Actually quite a few things need powder coated so I am just waiting to do all of them at once (need other things first though, like A/C)

Plans are focus on school, collect A/C parts and drive the heck out of it. Is it faster now that its tuned? Heck yes. I think it gained 20-30 horse and definitely gets up and goes quicker. Its starting to have that familiar 'pull' feeling that I love so much.

What else can I say. Rock solid reliability I put 1000 miles on it since last month. I did a highway drive economy cruise the other day and get 22-23mpg with about 120lbs extra in the car luggage, mid-day Florida sun shining 70mph highway. It will do better in the future but for now this is pretty nice, almost back to what the stock KA24DE engine gets on the highway (25mpg with automatic)
The first run:

So about 7psi of boost, notice that even with only 2-3psi of boost spooling in first the tires are already near their limits. Part of that is because the high cylinder VE due to the stock camshaft still being in the motor. When I finally install a proper camshaft the cylinder VE will drop in those regions (2400-3400) and the head/valve will flow more allowing more boost to make less torque in the low-rpm ranges where I want to spool the turbo and not blow the tires off. The reason it rises so slow and gently is because I have a large gate 44mm and using the weakest 3psi spring. With a heavier spring it should come on much faster and harder but all I have is street tires so this weak onset is actually tire sparing.
Most of my drives are 40minutes to 2 hours. I'm going to work on the A/C system next and enjoy it at 7-8psi for a while.

Last edited by Kingtal0n; 08-30-2018 at 11:47 PM.
Kingtal0n is offline  
Old 08-23-2018, 03:29 PM
CF Senior Member
Member Since: Aug 2006
Location: Clarksville TN
Posts: 519
Thanks: 0
Thanked 0 Times in 0 Posts

k-mart is offline  

Thread Tools
Search this Thread
Quick Reply: 5.3 4l80e 240sx < 3000lbs College budget

Sponsored Ads
Vendor Directory

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: