Kersh

All right, I’ll plead ignorance.

I know and understand the potential of the 2.0L Turbo (LNF) motor. What I DON’T understand is how anyone with the FWD’s go ANYWHERE fast.

My HHR SS is completely stock at this point. I’ve been compiling some go-fast parts (cat’d down-pipe, HPTuners, a Tune to use with it (thanks, DrLoch for your assistance), etc.) but I figured going into winter with the SS being my daily driver, I am waiting until spring to do any of the performance upgrades. I find myself considering NOT upgrading as I simply can’t get the power it has now to the ground.

When I bought it last year (with 25K) it still had the stock (original) tires. Traction was a joke. 1st gear was useless. We’re not talking about dumping the clutch and expecting it not to spin, this is easing into gear then mashing the throttle…as soon as the boost builds (up to the stock 14-15 psi) the tires go up in smoke. I wanted to pull the trigger on larger meats, so when spring hit and the snow tires came off (16”-ers I picked up off of craigslist for cheap) I went with 245/40/18 Cooper RS3-A’s for the factory 18” wheels. The Coopers are supposedly a much better tire plus being ¾” wider, I’d hoped for somewhat better performance out of them.

While it did improve, I’m still losing traction (BOTH tires, it has the LSD diff.) halfway through 1st about 90% of the time (occasionally, I do make it all the way through w/o spinning, but it’s rare enough that I think something’s wrong when it doesn’t spin ). Any bump, bobble, or debris in the road will allow it to break loose in 2nd as well, but that’s at least less frequent.

I try not to just allow it to continue to spin (as soon as it starts, I back out of the throttle to save as much tire as possible). Even with that, In the 10.5K I’ve driven since the tires were mounted, I’ve managed to take a brand new set of tires to the wear-bars…as in toasted (yes, I know I should have rotated them, but oh-well).

At this point, I don’t know what to do. I don’t seem to have a way to fix my traction issues, I can’t afford to be replacing a pair of tires every 10K (especially driving 15K/year), and It seems kinda’ stupid to add power to an assembly that’s capabilities have seemingly been surpassed.

Anyone have any suggestions? Am I missing something that others are doing for traction?

843de

Click on 2005HHRauto's username and check out his threads, he's our in-house "Mad Scientist" when it comes to running SS's on the strip, so he has info on getting one to "Hook Up" off the line.

Or shoot him a Private Message, I'm sure he'd be glad to talk with you.

Oldblue

I'm sure the SS folks will chime in but TTR upper engine mount ant transmission mounts come to mind!

DrLoch

If you are still on the stock tune, which it sounds like you are with the boost numbers you mentioned, it will only get worse when you put the other one in. I can give you a tune so it won't spin the tires if you want. As far as wearing out your tires, that is can also be controlled with your right foot.

1st gear in our cars with somewhat of a decent tune is like the pro stocks, use it to shock and set the suspension and tires then get ready to grab the next gear. That's why the automatics work so well, load it against the converter and let it up shift automatically. We aren't Ronny Sox, so we'll never be able shift faster and repeatably as the Auto guys at the strip. Now a road course.... different story.

Kersh

Thanks for your responses...

843de, I've looks over a lot of 2005HHRauto's posts, but I think a lot of his upgrades work because he's an auto guy. The difference between first gear (3.38 man vs. 2.96 Auto) and the final drive ratios (4.05 Man vs. 3.29 Auto) makes a BIG difference in first gear when comparing the two. I also have to look at this from the Daily-Driver standpoint. I can't run around on drag slicks (though it would be fun!!).

Oldblue, I do have the TTR upper mount (installed), I should have noted that. I haven't gone any further since I don't have ANY tire-hop issues. I don't want to make it TOO firm/solid.

DrLoch, While I'd prefer not to reduce power overall, I'd be open to reducing boost in 1st like some of the "can" tune people offer (ZZ Performance does, I think).

Can we do that through HP Tuners, or are they using a different program that offers them that capability?

Frankly, if I had the ability to control the "tune" that precisely, I'd reduce boost in 1st, keep 2nd close to stock (maybe a little more boost), and open up 3rd + up.

firemangeorge

Hmmm. If I remember correctly from all my previous reading/research, a stock SS 5 speed has limited boost in 1st gear. Somewhere in the 5-8 lb range. I seem to remember.
Not sure how you're getting 14-15 as you stated above. Maybe that's the reason. Overboosting could be producing too much power in 1st gear.
Even with the GMTU Stage 1, I think it still will have a limited boost in 1st. Somewhere around 10 or so.

Do you have the GMTU ?

As Oldblue mentioned, the TTR front engine mount does help somewhat. It is really good for eliminating the wheel hop the stockers have when breaking traction.

2005HHRauto

Wrong-wheel drive does really suck with the 5 speed.
The auto is easier to control as it only has a 3.29 final gear ratio.
The auto is boost limited, not the 5 speed, with a stock factory tune.
The tuners are boost limiting the 5 speed 'tunes' , in different RPM ranges in 1st, 2nd, & 3rd gears, to limit power, & to save the clutch & transmission.
Also the 4.05 HHR 5 speed is the preferred 5 speed for the Cobalt guys
as it is stronger.

Goto cobaltss.net to read up on what it takes to control the 5 speed, tune wise,
& tire wise, for street use...

Kersh

2005HHRauto, I corrected the error regarding the auto final drive ratio (I don't need to contribute to incorrect info on the "net")...Thanks.

With regard to the F35, I got the impression that none of the units are stronger (or weaker) but that the higher (numeric) final drive puts less stress on the tranny internals because it's transferring the stress to the axles, wheels, etc.

If I'm looking at this correctly, 1st gear in the Auto trans is actually closer to the manual 2nd gear when taking the final drive into account.

Auto trans w/3.29:1 final drive:
1st = 9.74:1
2nd = 5.33:1

Manual trans w/4.05 Final drive:
1st = 13.69:1
2nd = 7.13:1

Between the stall converter and the wide torque band of the engine, a tuned Auto has to be A LOT of fun to drive.

I always thought "rowing through the gears" was fun, but on this car, I can agree that the Auto trans would be A LOT faster for the street.