Chevrolet Cruze Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hey guys, wanted to follow up my hello post with a chat on what I'm currently working on.

I have a Cruze on the driveway and will have it for the next week. I'm working to finalize my 1.4 Turbo tunes. As I mentioned I've been tuning 1.4s locally upon requests for several years but the tuning I typically do for the platforms I specialize in and offer remote/internet order tuning requires a lot of seat time, its very indepth in terms of reconstructing control tables whether they'd be spark or transmission or in the 1.4's case it includes boost as well, optimizing this and that, there's many items I want to address before releasing anything on my website and that's what I'm doing right now.

It looks like I'm going to end up with 4 tunes, from the looks of it. Two will be 87 octane tunes, and two will be 91+ octane tunes, and of each one will be performance only related and one will be a blend of MPG improvements and performance. I'll explain more about those differences when the time comes but so far I like the 87 blended tune, its improved how the car feels to drive at part throttle, and I think it'll get much better with the 91 blended tune. I'm trying to get the 87 gas in the tank down right now so I can put 91 in, so I'm not calculating my fuel mileage so to speak, but I'll do so when I get the 91 in the tank.

The 87 tuning was very delicate, as you can imagine with a turbo engine. The factory tune uses a lot of adaptives for spark and boost. Several Cruzes I've tuned on 87 now have been limiting themselves to 12-13psi based on these adaptives, for example, so my 87 tuning I've now limited them to a max of 12-13psi. I've also fully reconstructed spark timing tables for both versions of the 87 octane tune, to reduce engine knock without the adaptives. Bottom line is my 87 tune, according to the GM torque PID, increased torque at 6000rpm by 9 from 109 to 118, reduced the spark knock retard at full throttle from 3-4* to zero knock, and as I've put it into several vehicles now the amount of spark learning that the computer needs to do is drastically reduced, where by comparison if I flash the stock tune (or unhook the battery on the stock tune) which resets the adaptives, the car sounds like a marble tumbler for a couple of days.

I'm also very happy with the transmission tuning, that alone has taken me 50+ revisions even with my experience level, but I've now transferred my final settings to 3 different vehicles, all with similar positive responses. Really cleans up the shift pattern at part throttle, the transmission is shifting how I want and when I want as I drive around town and module the throttle pedal, the car feels much lighter to drive and easier to drive. I've always prided myself on being the guy who can sort out a poor shifting auto transmission, and I'm real happy with how the Cruze trans has responded.

I've also mapped out the throttle response the way that I like it. From driving stock to my tune, you'll have to relearn how to apply the throttle, its a crisp response at any road speed and fixes that rubber band feel from a stop, but its very predictable, very natural feeling, you'll get used to it quickly.

Fuel Injector Upgrade

I noticed that the current fuel injector upgrade offerings lacked a projected tip like the factory injectors. Ideally we want to keep this. So I was very happy when I went searching a few weeks ago and sourced a fuel injector that is 48# and otherwise nearly identical to the factory units including the projected tip. I installed them yesterday afternoon, R&Ded the tuning adjustment required, and I've only had a small amount of seat time so far but they seem to idle well, no driveability changes from factory at all.

I'm also, just for the **** of it, going to test a second injector upgrade. This one will adapt some shorter fuel injectors with height adapters, which will require a couple quick cuts to the intake manifold where the injectors sit, but otherwise they're the same roughly 50# size, and I can source these very very inexpensively, as in a set of 4 could be sold for less than $150 a set even with height adapters. These don't have a projected tip though, they're similar to the Bosch green 42s in that regard, I don't yet know if they'll be a viable option but that's why I'll test and find out.

Brisk LGS Spark Plugs

I've seen the concerns about spark plug gaps on the forums, and I'll need to pull and check this vehicle as well before doing any 20psi testing, but if I can I'll also be testing a set of Brisk LGS spark plugs. I've used these plugs for years on other vehicles, they're in every car of mine on my driveway (except for the Cruze). They're a patented surface fire spark plug, developed by Brisk with Lamborghini, and are their OE plug. They should perform well, if, the factory coils are strong enough to fire them, which again is why I want to test them. I don't have any of the gasket seat type Brisk plugs on my shelf, like the Cruze takes, so I've ordered a set from my supplier and bent over on the shipping charges, so hopefully they arrive in time for me to check them out this coming week, otherwise I'll have to do that on the next round.

Few other items to look at as well, I made a couple videos 2 weeks ago to chat about the things that I wanted to work on, I'll post those below and will keep you up to date over the next few days. Have a good weekend everyone!

 

·
Registered
Joined
·
13 Posts
Discussion Starter #3
I also didn't post earlier but I wanted to mention how much FUN it is tuning and driving on these Cruzes. I truthfully didn't care much for the Cobalts, the forced induction was nice especially the supercharger cause I've owned GTPs but they never turned my crank as a car.

These little Cruzes though, they drive so well, the ride quality, I fit in the seat very well for being 6'4", attractive interior, the headlights are definitely my favorite aspect of the styling, lots of room around the engine to work on it. I've been leary of new GM vehicles and their quality, and I've been a GM guy all my life, its nice to feel positive about one of their vehicles again.
 

·
Registered
Joined
·
271 Posts
With all these tunes it seems it's about making more power, I am satisfied with the stock power of the cruze--especially compared to the Pontiac sunfire 2.2L it replaced, have you ever considered trying to improve the stock tune JUST for MPG increase ? I bought the cruze mostly for it's impressive MPG and I would guess a good majority of cruze owners did also, is it even possible to just up the MPG ?
 

·
Premium Member
Joined
·
949 Posts
Given your previous work with W-body tuning, I'm definitely looking forward to your work on the Cruze! As above, I would also be interested in reliable enhancements that kept stock power levels while increasing MPG (reducing DFCO delay, etc.).
Will these tunes also need to be separate for automatic and manual transmissions?
 

·
Registered
Joined
·
13 Posts
Discussion Starter #7
With all these tunes it seems it's about making more power...have you ever considered trying to improve the stock tune JUST for MPG increase ?
YES! I was working on that yesterday. It feels like an Eco button on some of the newer cars if you've ever been in one and pushed the button, except its actually doing something more useful the way I've set it up.

I've done a blended tune that controls boost at low rpms and improves MPG with the factory trans tuning, and if you go above 4000rpm you'll get the boost up and very good acceleration on 87 octane. Then, I'm also doing a reduced boost tune which will lower boost further at heavy throttle and use less fuel under heavy throttle and further help MPG.

Either of the two, you lose that turbo spool and surging forward around town feel that I didn't like anyway, and it makes a big difference not driving everywhere on 8-10psi. Some people who want to drive in a spirited fashion will notice that it doesn't allow that unless you give it some more gas get a transmission shift down and get the rpms up but 95% of the timing I'm driving "normally" it feels peppy and completely normal. And I can tell you on 91 octane, it feels even more normal, where the better fuel allows me to program the engine to make more power when not in boost.

Given your previous work with W-body tuning, I'm definitely looking forward to your work on the Cruze! As above, I would also be interested in reliable enhancements that kept stock power levels while increasing MPG (reducing DFCO delay, etc.).
Will these tunes also need to be separate for automatic and manual transmissions?
Cheers! With the one handheld method I'll be using, the trans and engine tunes can be selected and loaded however you please, mix and match. I'll only have the one transmission tune I think, maybe an extra "firm shift" tune on request. But I'll have multiple engine tunes that can be selected from and loaded.

The Diablo handheld by comparison can only do the engine tuning at the moment, though that's the handheld I prefer, as it'll allow me to rent you a wideband sensor and provide you a dyno like custom tune, where the other handheld doesn't have that capability. I've pledged to help Diablo with trans tuning support whenever they can look at it. For manual drivers like yourself, its a much easier choice.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #9
The bad news: I won't get to try the Brisk plugs this time around, just going to run out of time.

The good news: The 48# fuel injectors are running great. Its been a couple days now, car acts just like stock injectors were installed, no idle surging, no driveability issues of any kind.

Will be doing some more 91 octane tuning starting today, can't wait!
 

·
Registered
Joined
·
990 Posts
You'll need a tune to use a ported TB on the 1.4 it will give a okay gain but most people won't notice it on our engines.


Is that the biggest injector you offer?

Or all your tunes the same for every 1.4 "canned"or will it be a custom tune?
 

·
Registered
Joined
·
13 Posts
Discussion Starter #11
I imagine a ported throttle body would be worth some minor gains for someone who has a front mount and upgrade charge pipes. And a larger throttle body may work well in particular for faster turbo spooling; I've ordered two throttle bodies that I think are the most likely candidates for a swap, we'll see how they look in terms of size and adapting bolt pattern etc.

I looked and found these 48# units specifically for the Cruze when I started checking into what else was out there that could be used. I'm actually going to use them to upgrade the 3800 Supercharged platform as well, instead of the current injectors I offer, I like these new ones much better. Anything larger, I think we're best to just look right to a 65# injector, of which there's one I'd have in mind to try, should fit with some intake manifold modding, but I don't know what the streetability might be like. With these 48#ers, I saw pulsewidths at warm park idle around 1.0-1.1ms sometimes, 0.8 if it went into "hot fuel" mode and leaned itself out. The idle quality was tremendously good though, even then; compared to using a 65# injector on an LSJ and having the idle surge up and down and crap, this idle was steady as stock.

I'm going to have Overkill tunes for the Diablosport as my main focus, and custom tuning included, with the recommended ability to rent a wideband system from me to plug into the Intune/Trinity and provide me air/fuel readings during scans that I need to do a dyno-like and proper custom tune.
 

·
Registered
Joined
·
43 Posts
All sounds great really interested as you are from Canada so no duty!When are you thinking you would have these tunes and injectors ready for sale?
 
1 - 12 of 12 Posts
Top