Tim Sloper

I finally got my engine back in my car and running (well sort of). Here is the setup at the moment...

Comp XE-R 224/228 (actually 226/230 when I degreed it in) on a 112 LSA and 112 ICL.
98 stock heads milled 0.015" (10.6:1 CR)
TSP lid
LS1 intake
stock MAF
ported TB (used on my last motor with no issues)
JetHot LT non-emmissions headers
Hooker ORY

My question to those of you running the XE-R 224/228 grind with stock heads is how is your car currently configured for idle quality? I'm particularly interested in 98 setups but any year will be helpful.

Specifically...

- drilled TB? If so how big?
- LS1Edit running airflow table adjustments?

The problem I'm having at the moment is that I have the TB hole drilled slightly larger than stock. This combined with adjusting my throttle blade set screw gets the IAC at around 30 with the desired idle at 975 RPMs. The car will not stay running at initial startup unless I assist with the throttle. Eventually I release the throttle and the car will idle to a point. It will start with a very slight surge and then the surge will continue to increase to the point that the engine stops running.

Now... if I take my old TB blade from my last setup (much much larger hole) the car will fire up with no problem but the idle is artificially high (1400 or so). The last setup was a 226/234/114 grind with Stage II heads.

So at the moment it looks as though I have no choice but to either open the TB blade or drill the TB blade until I can find some compromise between the car firing unassisted and idle speed. This will mean IAC counts of 0. Of all the cars I've tuned mine is the one giving me trouble!

Tim

<small>[ February 25, 2003, 11:35 PM: Message edited by: Tim Sloper ]</small>

wicked 98z

I had hell with my old 224/228. I had the throttle body drilled a little and had Ed raise the idle. On some occasions it didnt want to stay running when cold. And would shut off on hard stops. Though when I drilled the TB it did help alot.

Tim Sloper

Ken sent me a beta version this morning with the IAC Park table implemented for the 98s. I'll try it out this afternoon.

Tim

CKZ

iTrader: (1)

What's the lift on this cam??

Also, I'm interesed in hearing your results on idle and performance.

Thanks

CK

CKZ

iTrader: (1)

TTT

KOOL C5

iTrader: (2)

[QUOTE] Ken sent me a beta version this morning with the IAC Park table implemented for the 98s. I'll try it out this afternoon.
[QUOTE]
I have been waiting for ever for this upgrade on Edit. How long before the update comes out? I have had idle problems from day one with my 422.

Tim Sloper

The lift on the cam is spec'd at 0.581/0.585. It did measure out to be 0.579/0.584. The IAC park table made all the difference in the world. It will now start without any throttle assistance. Eventually it will surge and die but that is due to not having the y-pipe on the car. The O2s are seeing air from the collector ends and pushing the fuel trims to their limits. I'll be correcting that this weekend.

Tim

CHRISPY

I wouldnt crack the T-body blade at all. I would leave it closed and adjust your IAC through T-body blade drilling alone.
I have a 230/230 cam and have IACs around 45 hot idle with no idling or surging issues. Base idle is set at 950 as far as I remember.
cheers,
Chris

CKZ

iTrader: (1)

When are you dynoing?

Is the idle fair or overly lumpy?

Thanks

Tim Sloper

Chris,

The blade is totally closed. I drilled a slightly larger hole. With a desired idle of 975 my IAC is ~30 which is about right. At 975 the idle is decent. I do need to get a y-pipe on there sealed down so the fuel trims no longer cause the surge as they increase but that's an easy fix.

CKZ... at 975 its not very lumpy. I won't try to say it is like stock because it isn't but it is not lumpy like the older camshafts we used to run. I will probably dyno next week. I have to get the transmission in it this weekend and then a few days of driving around to make sure there are no issues.

Tim

CKZ

iTrader: (1)

Good to hear, i'm local so maybe i'll come check it out? You dyno at Norris right?

That's the cam i'm looking into right now, and your set-up is very similar to mine

Thanks