stg2+ w/ 2.8 cams logs

**AudiTechS4** · 03-07-2015 01:26 PM

here are the logs from a normal stg2+ car with just the cams installed . no fine tuning for the cam changover
From some logs ive been looking at its hitting 220 g/ps about 500rpm sooner then other stg2 k03 cars . Yes the changeover needs to be tuned because these cams are just waking up and then the changeover happens.
Looks like they work on k03 cars. We did this to really see what they are all about because when i asked about doing them people were asking me why i would put them in . anyways here ya go .
Ill get a pic of the dyno before and after the cams . done a week apart

**Peter1.8t** · 03-07-2015 02:08 PM

It's just cams?

**AudiTechS4** · 03-07-2015 02:42 PM

no stg 2+
apr bipipe,apr ic's,ssac turbo back

**hibiscusS4** · 03-07-2015 03:16 PM

Doesnt look bad maybe there worth it

**AudiTechS4** · 03-07-2015 03:30 PM

when we tun the changeover i think it will be way worth it

**Peter1.8t** · 03-07-2015 03:44 PM

I meant as in just the cams, not the entire head changed.

**AudiTechS4** · 03-07-2015 03:58 PM

oh yes just cams

**01audia4** · 03-07-2015 05:21 PM

Just intake right? Exhaust are the same?

**AudiTechS4** · 03-07-2015 05:23 PM

yes

**Drehmoment** · 03-07-2015 05:56 PM

Are you running it on a off the shelf tune or is it already custom ? Guessing if you are going to tune cam change over it is custom already .

**AudiTechS4** · 03-07-2015 06:59 PM

yeah custom

Tuned cam change over

**Dalers08** · 03-07-2015 11:04 PM

I just picked up a set of cams for my car. Any write ups on doing this?

**AudiTechS4** · 03-08-2015 10:01 AM

use this - hardest part is the damn chain timing. also you need one of these

**FlyboyS4** · 03-08-2015 06:46 PM

Originally Posted by AudiTechS4

here are the logs from a normal stg2+ car with just the cams installed . no fine tuning for the cam changover
From some logs ive been looking at its hitting 220 g/ps about 500rpm sooner then other stg2 k03 cars . Yes the changeover needs to be tuned because these cams are just waking up and then the changeover happens.
Looks like they work on k03 cars. We did this to really see what they are all about because when i asked about doing them people were asking me why i would put them in .

What temps (outside and intake)?

**AudiTechS4** · 03-08-2015 09:13 PM

outside was 75-80 deg didn't log intake air temp or atleast it isnt in the log. only draw back we are seeing is the boost is dropping off at higher rpms. were going to change the boost profile to make sure we can hit requested. hopefully its the cams are drawing more air then the k03's can supply. either that or there is a wastegate/boost leak issue. we smoke tested it and there is a slight mount of smoke coming from the pass side wastegate area.

**AudiTechS4** · 03-08-2015 09:15 PM

you can see the boost log that its a steady decline

**FlyboyS4** · 03-09-2015 04:04 AM

Originally Posted by AudiTechS4

outside was 75-80 deg didn't log intake air temp or atleast it isnt in the log. only draw back we are seeing is the boost is dropping off at higher rpms. were going to change the boost profile to make sure we can hit requested. hopefully its the cams are drawing more air then the k03's can supply. either that or there is a wastegate/boost leak issue. we smoke tested it and there is a slight mount of smoke coming from the pass side wastegate area.

I've got a log of reaching 220 g/s at 3680 rpm and 18 psi, but 50F.

**AudiTechS4** · 03-09-2015 06:45 AM

whats your email , ill send you the log and you can overlay it and see any difference

**Jake@JHM** · 03-09-2015 10:00 AM

Tool:
https://jhmotorsports.com/shop/catal...8l-p-2168.html

Why not replace the tensioner/adjusters while you are in there?

https://jhmotorsports.com/shop/catal...7t-p-1308.html
https://jhmotorsports.com/shop/catal...7t-p-1309.html

**hibiscusS4** · 03-09-2015 10:06 AM

woah why are they so cheap? 200 bucks for a chain tensioner theres no way that oem

**Jake@JHM** · 03-09-2015 10:10 AM

We go directly to the OE Supplier. We have been using these for a while now without issues.

**Zba** · 03-09-2015 10:10 AM

Are you confusing OE with OEM?

**hibiscusS4** · 03-09-2015 10:15 AM

ya sorry i thought i say it say oem somewere

**Smokin Joe** · 03-09-2015 10:17 AM

Nice! I have a set of 2.8 heads sitting in my garage. Would changing the heads out too help or hurt? I know the 2.8s are supposed to flow better especially at the higher RPMs, but would it be too much for K03s to deal with?

**hibiscusS4** · 03-09-2015 10:23 AM

i think its been said the 2.8 heads and all are alittle over kill for k03s and possiably k04s 605s and up is were there good

**julex** · 03-09-2015 10:29 AM

after you change cams you also want to change the tune to change over around 5.5k, from factory 3.8k. Funny that on my tial 770 with 2.8 heads (not just cams), the 5.5k point is where the sweet spot is and changing there causes no drop in flow unlike factory measly 3.8k. Factory set up chokes 2.7t cams as well.

**AudiTechS4** · 03-09-2015 10:40 AM

julex we have the cam changeover at about 5250 rpm

**AudiTechS4** · 03-09-2015 10:41 AM

we never made it to 5.5k since the log of maf values were very smooth

**Monty23** · 03-09-2015 10:46 AM

Originally Posted by hibiscusS4

i think its been said the 2.8 heads and all are alittle over kill for k03s and possiably k04s 605s and up is were there good

Unless you are opening the motor up for rods (or something else like bad head/valves), I don't think the hassle of swapping on 2.8 heads on a well running motor is worth it imo. But to say 2.8 heads and/or cams are overkill for even k03s/k04s I think is a bit much considering there isn't any data to prove or disprove this.

This community has a tendency to take a couple people's "opinions" (that have no factual data to back them up) as the gospel and tell everyone else that these untested ideas are true.

**AudiTechS4** · 03-09-2015 12:56 PM

Exactly - thats why we are doing this . to show what cams do . we also have a set of 2.8 heads that have been gasket matched and slightly ported/polished/cleaned up that will go on next. kinda sucks though as the temps will be in triple digits by the time we get to them

**AudiTechS4** · 03-09-2015 01:01 PM

here is the dyno sorry its so hard to see as they made the lines all the same color. but this was 1 week apart. 1 run was the bas 2 runs were the cams you can see the gains from the cams here. hp is the top curve - you can see they started to make more power and the cam change over killed them but they carry the power longer at higher rpm . you can see the cam change over in the 2 runs compared to the base. thiis was before a retune with the cams , we wanted to see what they would do just throwing them in there.

**FlyboyS4** · 03-09-2015 04:22 PM

Here's the log I was referring to and your data. Yours is the higher boost (blue lines).

**AudiTechS4** · 03-09-2015 04:33 PM

I see what you were saying jeff , looks like you built boost way faster also . Ill log intake air temp next time with another revision.
when compared to another s4 here in az it this is what we get - both cars running the same tune.

**christianb5s4** · 03-09-2015 04:48 PM

So if I'm reading that last graph correctly, the 2.8 cams not only spool earlier but also hold power at the top end better than stock 2.7 cams?

**AudiTechS4** · 03-09-2015 04:52 PM

yeah , exactly . good upgrade , just make sure you tune for them . you can see the dip at 4k in the green graph on stock 2.7 cams

**slow ride** · 03-09-2015 05:10 PM

Unless you guys are running in the same conditions and plot throttle angle it's really hard to say.

**AudiTechS4** · 03-09-2015 06:33 PM

they are both wot pulls
the other log is from corradovolksb (brad helping with tuning)

**julex** · 03-09-2015 06:51 PM

Maybe I can shed some light.

All the online write ups on tuning unanimously say that overlap on cams sabotages spool up of turbo but I found the opposite the truth. Disregarding MAF readings (which might be deceptive since most of the gain might be actually due to heightened venting of cylinders, not actually engine using this air for anything tangible), I actually determined that on 2.8 heads there is a big difference in spool up with VVT engaged for a total of (Sic!) 44 degrees of overlap (22 from 2.8 cams and another 22 from tensioners). If left off, that would crudely simulate 2.7 cams with VVT one. It was several hundred RPMs on tial 770s.

That's a fact.

If you dyno the car (don't look at MAF!) and determine actual difference with VVT on and off at given RPM threshold of VVT going off (I will tell you right here that you should investigate 5.5k first as that's the break point for VVT), then you can determine where that break over point is.

Just look at RS4 stock tune and realize that Audi perhaps sabotaged S4 2.7t engine with low switch over point to make RS4 look better....

Again, MAF is not what you should be looking at since it doesn't tell the full story.

**AudiTechS4** · 03-09-2015 07:24 PM

i provided a dyno shows the gains at the cam change over

**uponone nogaro** · 03-09-2015 07:59 PM

Good stuff man i kep digging for answers and you answerd all my question they do perform good with k03 my car is getting 2.8 cams installed on thursday and a daz retune will follow after with meth

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