How important is Turbo Inlet Temperature in Tuning a 930?

Overpaid Slacker · 04-26-2004, 02:32 PM

I was going to name this thread "You know you've been spending too much time with RoninLB if..."

The ubermotor is going into the new body this week, and having spent the weekend traveling with Ron, I've caught the "need more gauges" malaise.

I'm ordering a Quad gauge from Westech and I've got the first three figured out: CHT/EGT/CHT. I'm thinking maybe voltmeter for the 4th (w/ an oil pressure warning light thrown in for good measure), but instead maybe a TIT (snicker) to help dial in the Electromotive. I went from 964 to SC cams this time around, so it'll need recalibrating.

Sidebar: If anybody needs a set of 964 cams w/ about 10k on them, PM me. There'll be a bunch of 930 ***** for sale soon, incl. a stock 3.3 turbo motor w/ 40k and GHL exhaust.

I understand the "need" for TIT in aircraft, which operate in a variety of altitude/pressure situations, and I'm wondering if anybody's got an opinion (a useful opinion, anyway) on TIT for auto tuning/monitoring.

Frankly, if anybody's got an opinion on the utility of two CHTs (cyl's 2 and 5, I figure) and only one EGT (very near the head) I'd be interested in that, too.

TIA,

JP

RoninLB · 04-26-2004, 09:21 PM

Quote:

Originally posted by Overpaid Slacker
I was going to name this thread "You know you've been spending too much time with RoninLB if..."

The ubermotor is going into the new body this week, and having spent the weekend traveling with Ron, I've caught the "need more gauges" malaise.
JP

this itch that JP is trying to scratch is connected to an old EGT 5 page thread

http://forums.pelicanparts.com/porsche-911-technical-forum/89442-monitoring-cht-egt-5.html#post1283824

Overpaid Slacker · 04-27-2004, 06:15 AM

Bump.

C'mon, HP Junkies. Where the Hell are you guys when a brother needs you?

JP

tsuter · 04-27-2004, 06:24 AM

TOT is far far more important that TIT if your talking about turbochargers.

And TAIC is more important than TBIC for that matter.

And if I gotta explain the acronymns then it don't matter at all. LOL!!!

tsuter · 06:47 AM

Some folks want to see TIT pictures so here is one.

That would be TIT measured on the left and TOT on the right. And yes correct, there is no IC in this picture.

edit: But there is an MBC pictured and a BOV!

Zeke · 04-27-2004, 06:51 AM

Oh you guys are just having too much fun. Turbo inlet, turbo outlet, aren't the two directly related? In lay terms, the cooler in, the cooler out? CICO, hehe.

MotoSook · 04-27-2004, 07:03 AM

crap..damn computer/net screw the reply I was typing...TIT is useless unless you have a proven algorithm to process the info...monitor intake air temp...post cooler...else, there are unknows.

tsuter · 04-27-2004, 07:08 AM

I got a 3" red TIP that you'd use to measure her (the 911) TIT but if you want her TOT, my TOP's only 2.5"

tsuter · 04-27-2004, 07:09 AM

"Useless TIT" Souk??? Ohh OK I see.....

Overpaid Slacker · 04-27-2004, 07:13 AM

Just to make sure we're talking apples and applies, I'm referring to TIT as temperature just upstream of the turbine in the exhaust. It can be 100F higher than EGT if unburned fuel is making it into the exhaust and reigniting when it hits the pressure wave upstream of the turbine.

Again, I understand how this is useful info for an aircraft frequently changing altitude/pressure, but I'm less and less convinced it'd be useful in a car. This kind of loopy question is what you get when you shop for gauges from an aircraft catalog...

I've got a Kokeln intercooler, and hadn't thought of taking the air intake temperature downstream of the I/C b/c I'm not sure what I could do to alter it, short of changing I/Cs.

Thanks for the replies, guys. Looks like I'll just add a voltmeter.

JP

MotoSook · 04-27-2004, 07:19 AM

I like TITS Thad

Really, in the lost reply I was in agreement with you...the short of it is that which JP just stated, not that applicable to his car, right? Or have you got a super secret program you haven't told me about?

tsuter · 04-27-2004, 07:19 AM

The turbocharging acronym TIT would generally be refered to as Turbo Inlet Temperature at the TIP (turbo inlet pipe) and it is managed or attempted to manage by using various CAI (Cold Air Intake) devices replacing stock air intakes.

tsuter · 04-27-2004, 07:25 AM

For TOT, Turbo Outlet Temperature you want to measure in the TOP (turbo outlet pipe) both before and after the IC to determine the IC efficiency. hence TBIC and TAIC. You should also measure boost before the IC in the TOP and in the Throttle body as IC pressure drop is also a measure of IC efficiency. The boost controller should be after the IC for that reason.

tsuter · 04-27-2004, 07:31 AM

Your Kokeln intercooler could possibly be water cooled when the TAIC indicates heat soak.

Overpaid Slacker · 07:39 AM

tsuter -
I suspected you and I were using TIT in different ways, and it's my fault. I should've written "Turbine Inlet Temperature" instead of "Turbo Inlet Temperature". The turbocharged aircraft stuff I'd been reading simply said TIT, w/ the assumption "everybody would know" that they were referring to a temperature taken upstream of the turbine in the exhaust. I made the same mistake.

As for TBIC and TAIC, I agree with you re: the utility, but only if I'm designing or auditioning intercoolers. Otherwise, it is what it is, no?

Granted, a CAI device might affect TBIC, but the TBIC-TAIC delta curve is still effectively fixed by the I/C design, and knowing that delta wouldn't help me dial in the Electromotive, would it?

JP

EDIT -- good point about the TAIC and water-cooling system (another gadget I'll get to in the future muuhuhahahahaaaaa) but I don't think that'll help me set up the Electromotive.

tsuter · 04-27-2004, 10:26 AM

Sorry can't help on the Electromotive. My SC Turbo is 100% mechanical by intent.

I have Delphi Automotive Engineering programmable EFI on my Harley, and its a different world using ion sensing, VE and ignition tables MAP, TP%, on and on... nine tables plus tuning constants like injector flow rate, rev limit etc. With the laptop bouncing around on the back!

I just hope Electromotive doesn't use a Mass Air Flow sensor (MAF). I'm about to yank that thing out of my 02 Turbo Beetle and put in a programmable MAP solution on it.

Amac · Amac's Garage

JP,
The cooler the intake temp. the more HP you can make.
But as far as tuning, I don't know how knowing the intake
temp. could change anything.
I run Motec and I can't remember it ever coming up.
The temp. before and after your IC is what it is at the time
your on the Dyno for tuning.
The real bad ass "HP Junkies" only need to see three things;
1. Oil pressure
2. RPM's
3. Boost
Have you posted pic's of this car your building?, sounds cool!

Overpaid Slacker · 04-29-2004, 06:10 AM

Thanks, guys. I appreciate your input. I think I'm going with CHT/EGT/CHT/Volts. I think a TIT would not provide information helpful to my needs right now. Westach said it'd take five weeks to get! Yikes! That is not a good answer for immediategratificationboy.

If I need to gauge the beast up any further, I'll just get another quad; which will leave me only about a dozen metrics short of Ron.

Amac - No pix yet. I'm actually a little embarassed at the moment b/c the p/o swapped H4s into the car and didn't paint the (black) bezels. He said he liked it like that! So I've got a petrol blue car that looks like it's got two black eyes until I can get it painted.

JP