Considerations if starting to mod a stock car
 

One of the issues with starting the mod process is if you break more that you fix. These cars seem to be a little touchy, so you have to be aware of potential issues as you change parts.

I found that doing one mod at a time and dialing it in was easier than doing multiple, and chasing issues...

Ill provide some examples, and chime in if you have others:

82mm Throttle Body - A lot of people have issues after this mod with CE light and poor idle. My suggestion: Go with a kit that does not use adapter, do TB reset and get it tuned for new TB.

Pulley - Numerous have fallen off, and its not fun. There are many write ups on this, so read up if you are doing your first pulley. I use an ASP pulley torqued to factory specs, and have not had an issue. I am on my 3rd pulley, and never a problem, but beware. It can be an EXPENSIVE fix

Dampened OEM pulley with welded ring (and the balanced) has been shown to be reliable. There have been other types released, and problems blamed on them. All 3 of the pulley I have used were ASP built on an OEM dampened unit. When shopping for a pulley, this is a great first question. (Not saying others don't work, I just know so far I have had no issues with the original design)

Electrical - If you mess with anything electrical, you stand a good chance of setting off the SRS light. Not sure why it happens, but it does. I read that you must use star diag to clear the issue once it happens, but when I have tripped it, it goes off in a "while" on-of-on-off.. 20 minutes later, it stays off.

Battery - If you disconnect battery, you will probably need to reset Pano roof. (Don't know about sun roof, but possible) There are write ups on this procedure. If the movement stutters, it just needs reset

Fuel Rail - When doing fuel rail, be cautious with injectors. You can push them into the rail too far, and it leads to a lot of frustration. Put them in only a very small amount, and as you seat the rail, the injectors will slide in to the correct position.

Exhaust - If doing custom exhaust work or adding headers, use "good" v-bands, or weld. The cheap v-bands will leak a little, no matter what. If you are like me, exhaust leaks are unbearable. The good V-Bands have a small lip machined into each side that seals the two rings. Welding everything together eliminates the issue.. Just cant ever remove exhaust without a saws-all

Tuning - I have seen issues where the SC will simply stop engaging while tuning. Seems the ECU gets freaked out, and just shuts it down. Simple fix: Battery reset. I have seem a lot of work go into troubleshooting this issue, and all it needed was a reboot.

Tuning - At a certain level, if torque limiters are not modified, you will get a hesitation at the shift points. Feels like a trans problem, its not. Its the TRQ limiter.

Split Heat Exchanger - There is a good DIY, and very straight forward. Not too much to worry about here.

IC Pump on with key - I wired my pump from battery, through a relay that is triggered by the Cig Lighter switched power. This allows the pump to run with key in accessory position, and at all times when running. Simple to do, and helps. If you need instructions, let me know, Ill post up.

Mechanic - It is very helpful if you have a certified mechanic that you can have do your mods. My guy is not certified, but knows these cars upside down. Strange things happen with these cars where the fix is not obvious. Having someone that has "been there done that" helps a LOT. (From Hammer Down - Thanks!!)

That's about all I can think of off the top of my head.

There is nothing more frustrating than doing a mod, and messing something up. So hopefully this thread will grow with input from others, and help you get your mods in, and maintain perfect drive-ability.

good info

Great thread....Seems like we should create a step by step too (e.g. first get an OBD2 & WB, then blah blah blah) and expected gains, as well as downsides...

On the pulleys I have a question. I thought ASP weld a larger steel ring on a oem pulley and have no frequency dampening at all. MB puts a frequency damp on every M113 v8 they make.
This is why I think Iam going with a kleeman pulley they Have the frequency damp, already have there headers and tune mine as well. Wouldn't that throw the balance off ?

Incorrect. ASP uses a dampened OEM pulley hub that has a larger ring welded and balanced on top. I believe Kleeman does a similar process.

There are a few vendors that do not use the the OEM hub and I would stay far away from those....

Good info, thanks for sharing. Will you post the wired IC pump process please?

Hope they make this a sticky.

Definitely HELPS to have insight from other MODz.
Thanks for ALL GOOD info.

Thank you for great information. I have bookmarked because I will be back to reference something.

If I may add it also helps to have a REALLY good MB Tech to install everything. I had Top of The Hill Performance install my headers and my friend who is also a MB Tech (well use to be now he's the Service Manager) install everything at the same time and I polished it off with a OE tune through TTM Motorsports

Good conversation, and where new info is provided, Ill edit the first post to include your information. Thanks HammerDown, your advice is good, and I agree completely. Also added my view in terms of pulley design per discussion in this thread. Where I use brand names, it is only to provide information on what I have personal experience with. I don't intend on making this a commercial for anyone

(BUY PEPSI) j/k

Back to the point of this thread.. Having done a lot of mods, I always worry: Am I going to screw something up. And I have, and that is opposite of my goal :)

I would stay clear of a welded pulley and I'd like to know how they balance a welded pulley.do they grind the welds off and redo it lol.

Seriously a welded ring has unbalanced weight and I would NOT run a welded pulley.

great thread!

In general as far as mods go, what would be the preferred order to do mods if you aren't doing full stages all at one time?

Some say headers should be first, some say a tune, some say a pulley + tune...

I went with a tune first, then added the S/C pulley - but I can see why headers are important now as that's the restriction (stock!) even more now with more air being ingested...

They drill holes to remove material just like they do stock. It wouldn't surprise me if there are more ASP pulleys out there than any other brand.

Asp makes non welded pressed pulley's just like renntech,kleeman,brabus,evotech etc.

I'm just saying I would not run a pulley with weld blobs on it for the fear of throwing the whole reason why we have a balanced harmonic damper on our cranks

One other add to contribute...

Data logging - If you want to make more power than the best investment you can make to insure safety is a good data logging system ideally that not only does the OBD, but also AFR with a wideband sensor. There are plenty of good options (zeitronix, innovative, kiwi, torque) but it should be available upon the first mod/tune for best possible safety. I believe cij911 mentioned this and I'd stress it again. I've done every mod myself on my car with the exception of the tune, and it's saved me a ton of time and agony troubleshooting since I knew what was going on and allowed for better tuning since we all know dyno's aren't perfect.


IAT considerations - Make sure your IC pump is working since they fail! Additionally, always bleed the supercharger whenever it's cooling system is touched. This applies to the split system, pump replacement, HE install, and also the TB install. It may sometimes apply to the pulley install depending how you go about it since I've seen some move the radiator out of the way but not remove it. Personally, I removed my radiator upon pulley install but to each is own.

Gotcha and fair enough. I have one of each from ASP. One welded and one pinned and your point makes sense however the welded version worked perfect on my car. The big benefit I see on the pinned version is that it keeps the weight down on the big pulleys since it allows them to use aluminum instead of steel. Maybe that was your point that I missed.

I would only run a welded pulley as it is based on a stock unit. Had issues with a non welded and we all know about the RTR pulleys that I believe are no longer sold. Guess either works if you receive good example.
Additionally, to the top, I understand the IC pump always runs once the RPMs initially pass 2k. Then it stays on from there. Great thread.

On the pulley side this is why I went with Kleeman, they are known to be reliable and have relatively no issues.. Wish it was a little larger, but it is very safe in 168.. Might go to a smaller ASP S/C pulley to add just that little extra 2psi..

I personally started with Kleeman tune and pulley and went to long tubes after that...