Supercharger Experts?

[gottogo]

Hi Everyone. Any tips on tuning a 2002 Bonneville with a SC? I've been tuning for a bit now and I'm comfortable on a NA engine, but anything I should be warned about with this?

Any problems with the Bonnevile on HPT?

[gottogo]

Nothin'?

After a 21 hour soak?

[Eddie-98GTP]

My only fuel injected tuning experience is with a supercharged engine. I'm not sure too much is different, other then shooting for 11.3ish AFRs with a maximum WOT spark advance of 20-22* (I run about 17* at about 11.8 AFR).

You have to watch boost, it's easy to hit 4-5 psi at very low RPM when in 4th gear and lockup. This can cause KR, especially when it hot outside. The TCC Spark Modifier is a great place to stop this. I pull about 2* between 480 & 680 g/sec and between 1400 & 1800 RPM. With a few other TCC spark mod tweaks, this pretty much took care of all of my lockup spark knock.

If you drop a pulley size, bu sure to have supporting mods first. You want to be sure you have a good free flowing down pipe (the GP's had a terrible U-Bend restriction), a good CAI, and I'd drop to a 180* thermostat (remember to change your cooling fan on/off temps). Others will say you should have at least ported exhaust manifolds and/or higher ratio rocker arms, but on a 3.4 pulley you should be fine with the first 3 I mentioned.

When tuning you spark tables, a very good starting place is with the 04-05 GTP high octane spark table. This will give you a nice increase without being too high. Be sure you lower your AFR Spark advance table first. I set mine to add 1* at 11.7, and add 3 * at 10.7 and 9.7.

Hope this helps!

[danthurs]

Are you a member at www.bonnevillepro.com We have several tuners there using HP tuner.

No problem tuning a bonneville, do mine all the time.

The biggest difference in tuning a supercharged engine is the AFR difference. Shoot for 11.5:1-11.7:1 You really need a wideband to tune good. If no WB then your narrow band should be about 940

[n0dih]

And don't forget 3800pro.com too....

Are you saying 20-20 degrees in the high/low octane timing table or measured? I have KR issues when I push timing over stock and my combo is stone stock other than gutted airbox.

Advice? LOW timing can be very destructive as well as high, as EGT's will soar, and make sure you are running sufficient octane.

do NOT get into the habit of copying the high octane timing into the low, this is a 3D table not a 2D, it isn't switching between the tables, it is using the high as a high limit and low as a low limit and the adaptive octane scalar is the % between the 2. So you need to have enough low timing to have a "place for it to go" if KR is a problem. Broken pistons suck, timing high and low can do it.

And as Eddie said, enough fuel is very important, leaning out is potentially very destructive.

[Eddie-98GTP]

If this was directed toward me...

Are you saying 20-20 degrees in the high/low octane timing table or measured?

I meant commanded timing by the PCM. Over 22* does not provide additional power. I personally try to shoot for 18*, but I'm not one to really push anything too far.

[n0dih]

My stock table, as is every single L67, is like 10-11 in the high table, and a bit of a peak around 2400-2800 rpm of 13ish.

Mine at least has never been able to tolerate much at all in that table, it always get KR's undies in a bunch. I still think something is up, but can't figure it out....

[Eddie-98GTP]

I'm assuming you're talking about the bottom row of the high octane spark table, correct? Remember, the AFR Spark table is also adding as much as 7-8* depending on AFR.

[n0dih]

Mine is stock, and only adds between 1-3 depending on AFR of 12.7 to 11.7, can get up to 8 if you are up to 9.7:1.

All the L67's are the same that I have looked at. I'll datalog on the way home and look, but I haven't seen it ever run that high at WOT.

[RWTD]

No IC/HE system on these beasts, 'eh? That sux!

[n0dih]

Nope, wish there was!

[Eddie-98GTP]

Mine is stock, and only adds between 1-3 depending on AFR of 12.7 to 11.7, can get up to 8 if you are up to 9.7:1.

All the L67's are the same that I have looked at. I'll datalog on the way home and look, but I haven't seen it ever run that high at WOT.

On a stock engine you probably haven't, but if you get someone who is not familier and/or experienced in tuning, it's easy to get the PCM to command a low AFR (10.7 adds 6* on my car stock) which still having actual AFRs in the 12's. I just pointed this out so the OP would keep this in mind when adjusting timing...

[n0dih]

When I started dropping the AFR down it doesn't take much till power dropped off significantly due to too rich.

I need a WB... bad.....

[gottogo]

Sweet! You guys are great. Thanks for the info. When I get a chance I'm going to see what I can do to this mofo.

But safely!

I'm attempting to build my own air intake right now, and if it works well I may have to make one for the Bonneville. That stock intake looks very inefficient.

[danthurs]

Perhaps this will help you build your air box. It's a step by step write up.

http://www.bonnevilleforum.com/t280372/

[gottogo]

Perhaps this will help you build your air box. It's a step by step write up.

http://www.bonnevilleforum.com/t280372/

Nice!

[GTPNoga]

The TCC Spark Modifier

Eddie, where is this table? Or is it only Accessible via the PT?

[Eddie-98GTP]

I can tell you where it is in the hex, but as far as I know it's not available in any commercial tuner package. Sorry, I've been using my own editor so long I forget what's available in HPTuner and/or PT...

[GTPNoga]

Can you tell me where it is in Hex? I am having that same exact problem 4th gear lock up 1900rpm and knocking 1-3* under load.
Thanks..

[n0dih]

TC2 has it also. This is my stock L67 PAU, it is not used stock.