Wert842

iTrader: (3)

The F40 + zfr set up would be kickass but for just the trans setup is like 4k. Crazy expensive compared to a 4.45 or 4.05. The 4.45 is so intense though. The pull is incredible and still wonderful. Just wish it was a 6 speed from to time cause long trips are loud cause it is revving so high on the highway.

09CobaltSS1

While I'm not the biggest fan of Mitsubishi turbos, they really aren't nearly as bad as they're made out to be around here. It's primarily an issue of knowing the turbo characteristics and tuning the vehicle accordingly. The low end surging that is common in the 20g isn't related to the adaptor Hahn uses or even issues with the stock manifold as some might try to claim. It's simply an inherent characteristic of the turbo. If you try to push 20+psi below 4000rpm you are far below the turbo's surge line at that point, which will cause the turbo to surge. Anyone who can read a compressor map can clearly see this. Simple solution, slow spool time. Tons of testing and tuning isn't needed to determine this. I'm not defending Hahn or the 20g and saying you should have just slapped a 20g on there instead, because clearly you ultimately ended up with a superior turbo imo. I am however just trying to clear up a terribly incorrect misconception about the turbo that some seem to have.

alerosaint

Must be nice I get 30 mpgs tops and haven't even seen that lately.....but I do drive hilly places

08VRSS

Yes, but in James' thread when he dyno'd the hahn s20g it was mentioned that he had the surging at the upper rpm range when boost was around 26 psi then he had to drop it to 24psi for a few hundred rpms then back up to 26psi. I'm not saying James is THE best tuner out there, but I trust the guy. Can you offer your explanation why this possibly happened? I always like learning new stuff.

Edit:

lol every thread i've just searched you posted in.

Ahhh found it... Quote from James in lnf hahn s20g dyno thread:

"25lbs on a 20g isn't technically 400whp. If timing is great and the boost is efficient then yeah. But lnfs are different within the kit. The 20gs get massive surge on the lnfs with Hahns kit . I've replaced the adapter to a smaller bend and I got less surge and it gained more midrange of course but a lot is timing and boost up top"

"Now why would I do the mix. Because not everyone has the 91 or more. And the gas station didn't have 92 only 91 89 and 87 so I went with a more baseline of what numbers can be hit. I even explained myself on why I did it in the thread. My car is actually quicker now then it was then and I'm on 93 octane 14* mid and 17.5 topend (because I'm not getting kr) but also because I keep my 26 til 5k which i have it go to 24lbs then at 6k I raise it to 26 BECAUSE SOME SURGE!"

Next post was by lazaro:

"Yea my tubo surges like a mother"

Heres the link to the thread:

https://www.cobaltss.net/forums/08-1...80/index3.html

And just for reference, I'm a big fan of the 18g, 20g, t67 25g, etc, they do pretty well and are pretty cheap/ reliable to boot, just maybe not the best match for the LNF.

09CobaltSS1

I have a bit of a love/hate relationship with mitsu turbos really. They aren't by any stretch the best turbo around, but they are inexpensive and relatively reliable for the most part. Some lnf's I've dealt with took perfectly well to Hahn's 20g setup and others basically hated it and more or less crapped it out.

As far as surging goes. Generally speaking, the most common issue that would cause surging mid range or up top could be basically the turbo pushing more air at a given point than the engine can take in. Possibly due to a restriction, or even the throttle plate closing. Sometimes even the incorrect bov setup can sometimes cause what looks and sounds like surging, but is really just essentially the bov and turbo flow fighting one another in a game of flutter. I went through some random 20g logs as a reference and I'm really not seeing any issues with surging up top. I am however seeing quite a bit down low if boost, cam timing and other factors aren't set up just right. Another issue they tend to have more so than just about any other turbo on the lnf are high egt's. Granted there is no real pyrometer to go off of unless one is installed aftermarket, but you can clearly see it becoming an issue up top with an apples to apples comparison using the stock sensors the log supports what the egt's are showing.

08VRSS

I can agree with that, thanks for your insight. If the optimum torque and optimum timing tables along with the PID tables aren't setup correctly, they can definitely cause a restriction trying to fight the throttle plate by closing it in the upper range, and yeah cam tables too I can imagine. All of these tables on mine are very far from stock.

InfraRedline

iTrader: (4)

Great review. I am sure you have easily achieved your goals. A friend of mine had a ZFR with the bolt ons like you and was on E47 and 25-26 lbs and when we tuned it, the car was out of injection window at 5900 rpms, but he liked the power so didn't want to turn down lol, but it made 420whp and 410tq.

08VRSS

Did you guys get misfires, or just the drop in fuel pressure and raise in injector duty cycle?

InfraRedline

iTrader: (4)

The car would get injector window misfire above that. He now has a pte5857 and is doing his valve springs and zzp cam soon.

08VRSS

Did you guys try shifting the injector window? Or just leave it alone? I'm not having any issues yet, but haven't been able to go above 5800 rpms many times in gd Houston traffic, and the few times i did, i wasn't logging. I'm getting to 7.3ms on my injectors around 5200 rpms which is kinda high, but fuel pressure is staying steady up to 5800. My injector timing tables are stock but my cam tables are far from stock. I think i may shift my injector timing a bit, still doing research on it though trying to see where an ideal shift would be depending on my cam timing, I don't want to guess and make a blind shift on the injectors lol. The cam tables are pretty damn good though, my MAF and VE readings are pretty much dead on matching to one another.

To do list:

1.) Injector timing research
2.) aeroforce interceptor
3.) zzp stock intake cam with fuel lobe

Wert842

iTrader: (3)

I know you do have to mess with it to get it perfect. It took a good solid 4-5 revisions until we stopped my problem. My biggest issue was right around 4800-5k when the car would buck a tad. There was times when getting my car revised it would happen between 4.5k and sometimes up higher like around 5.5k. It was a horrible time at getting it perfect. It also has to deal with the WG canister installed on some of the zfrs that were causing a slower than average spool compared to others.

08VRSS

Any idea which way the injector timing was shifted? I'm seeing two different sides on hptuners forums, one is saying narrow the window by starting the injector later and another says start the injection earlier. Im going to try to lay out my cam timing to see what would be ideal.

I have no issues so far like that though, just worried about the upper rpms injector ms. Plus im only boosting 22 psi up to 4500 rpms, so that why im probably not seeing an issue like you were.

alerosaint

you can also PM cobaltssoverbooster on HP tuners forum....he has a really good grip on the lnf, he might have a good answer for you

Wert842

iTrader: (3)

I'll have to look when I get home. I noticed it varying a couple times but never actually looked at the final product.

I gotta get into it more and figure out somethings. I was tuned by term2 and now he is out of the game so I'll be looking to do it myself with the of some guides. Hopefully. :/

09CobaltSS1

Injection window and/or rail pressure drops shouldn't really be an issue up top with the right injector timing set up even at that boost level. The only time it becomes a prominent issue is in high torque area, such as 3500-4700rpm, where fuel demand is greatest.

There's part of your issue right there. Even without my 5th injector spraying I hardly ever saw much more than 7ms beyond 5k and that's with e47. On 93 you shouldn't see much more than 6ms that high up in the rpm range especially only running 22psi.

09CobaltSS1

You've got my number home slice. Don't be afraid to bug me. I just might not respond immediately.

InfraRedline

iTrader: (4)

The IDC was highest in the higher rpm range. It was a 60/40 mix of E85 and 91 since our premium doesn't have 10% ethanol, so probably a little stronger than E50. It didn't have any issues getting to 6500 until the summer blend came around. Either way, the car has a new setup now.

08VRSS

I'm also on E47, 7.3ms was the highest i saw in the log, are you supposed to inject sooner to help this I'm assuming, ie raising the values in the hom low table? Whats a good way to experiment, how much adjustment at a time etc? hp tuners forum is very slow to respond. At 5200 rpms I'm already at 25-26 psi, I'm thinking the only thing saving me is that i scaled down the maf in that range a bit to compensate for the alky/water injection.

Do you really have to lay out your cam timing and find the correct place to start injecting? Or is there a simpler way to do this?

And thanks for the help so far.

08VRSS

well i guess i answered my own question, mapped out my cam and shifted my injection timing......and quite a difference it made....... Im at 6.9ms where is was at 7.3 before shifting it, and 6.4ms and 6000rpms. No issues i saw and it actually feels smoother. This is as much as i could push it with traffic, and i lowered boost a tad. Theres also an example of how good the zzp smaller intercooler is at keeping IATs in check.

08VRSS

Also wanted to share, I got my KY clutch for $86 cheaper than TTR offers.

I'm glad i got mine before TTR has a hissy fit about another guy undercutting them on the price and tries to have them remove it from their site lol

Bought my kit from Kruman Custom Cars Performance located In PA, great service.

TTR : $430
KY Clutch - Chevrolet Cobalt/HHR 2.0L F35 Trans Stage 3

KCC Performance: $344
KY Clutch - Chevrolet Cobalt/HHR 2.0L F35 Trans Stage 3

08VRSS

Update:

Still going strong on the ZFR, now minus the E47, back on 93 octane. 4.05 tranny still holding up, KY stage 3 still holding. Still a fun daily, front tire sets since ZFR, 2 sets down lol.

Back when she was running E47 and on the way home from work:

tomj77

iTrader: (2)

my zfr fried my ky stage 3 clutch. installed southbend stage 4+. so much better clutch

09CobaltSS1

Ya know, it's sort of funny you say this. I've had my kys3 clutch for over 3 years now without as so much of an issue. Same thing goes for the multiple other kys3's I've installed on other balts. Now on the flip side, I've now had 2 southbend stage 4+ clutches come into my shop (towed not driven) that were shot and both had the identical problem. One of which was actually just last week. In both situations the disk hub springs were shattered and lodged in between the disk and flywheel. Not a cool thing.

It's just interesting how polar opposite experiences people can have with the same exact products. The thing is, I was reading up a bit more on these southbend clutches and it seems as though the disk springs are a bit of an issue. I'm not saying their a bad clutch, but I'm also not saying they're worth every penny of that $700+.

I just hope yours holds out a bit better. I'm sure it will, but just maybe keep vigilant for if the trans starts to seem like it's hard to get into gear at times.

blueLNFftw

iTrader: (16)

Damn.
I wish I would have seen this review of the KY clutch before I installed mine. I never would have used it.

09CobaltSS1

I wouldn't be too worried about the kys3. Like I said above, it seems to vary quite a bit from case to case. I've actually seen more issues with the southbend clutches than I have with the kys3. It's really just a crap shoot in the end.