Comparison between 14cm/16cm... EGT's,Boost,RPM's

[BushWakr - RIP]

Guys, I wonder if any of you who have a 14cm either wastgated or non, could tell me what kind of EGT's your seeing with WOT, empty/loaded.

In particular, I'm thinking of those who have some mods to the pump timing similar to mine.

What boost #'s are you seeing?

Mileage?

What RPM's are you at WOT?



etc, etc.



Thanks in advance.



Bob

 

[KEENO]

14cm2

Hey BUSH!



I thought that you might get a better response than you have on this one.



I don't have any hard numbers for you and a few opinions based on two different First Gens that I drive often.



The girl's truck has always had the 16cm2 on it an spools up nicely. Her down the interstate unloaded boost numbers are between 4#-6# @ 70mph. Max boost is around 25#-26#. This truck has much more smoke during acceleration than my smaller housing equipped truck... . But it 'feels' relaxed on the interstate.



I've had both the 14cm2 & now the 12cm2 on my truck and they've been swapped back & forth a few times. For my style of driving I like the 12... . But never disliked the 14cm2. I still feel that the 14 is the best compromise of all housing choices.



With the 14cm2 on my truck I would see 8#-10# of boost on the interstate w/ a Max. of 28#. EGT isn't a problem w/ the 14cm2 and isn't a problem w/ the 12 that I currently run. Max. EGT w/ the 14cm2 was 1150-1200 approx.



I still have a Banks "Big Head" wastegated 14cm2 sitting on the shelf if needed. PM me if interested.



Hope this babbling is of some value... .



KEENO

 

[bflood]

BushWakr, I have a 16 so I can't answer your specific question . . . but I am interested.



I see max boost of 25-26# WOT. I get 17mpg around town unloaded and 22+ highway at 65mph. I don't have a tach so no info there.



I do have a problem with EGT's during heavy hauling . Was pulling 17,000# and climbing some serious hills a couple weeks ago and had to ease up on throttle and shift early to keep EGT down to 1200F (pre-turbo pyro gauge).



What are you seeing for EGT's with your 16?



I think I need to look at timing and opening up exhaust. Maybe go to "straight pipe" (can't afford a new system). Actually I'd like to find a butterfly cutout exhaust valve where I could switch to straight pipe at will. I'm going to post this if I can't find anything in a search).



Any ideas (anyone)?

 

[BushWakr - RIP]

KEENO, bflood, thanks for jumping in. I was a bit dissapointed in the respone too, but there seem to be some other "hot" topics at the moment.



At the moment, if I go WOT/25psi/OD/empty, I see a peak of about 1100*F. It slows as it approaches that temp and doesn't seem inclined to go past but then I run out of hill and ticket money too.

I'm kinda debating the 14cm to help with spool-up, low end smoke (not really bad since I defueled a bit).

I'm really only concerned that once I stick a load on it and start a climb, (we have some doozies here in BC) I may have EGT issues with the 14cm.

I'm also going in for a DTT job pretty quick and that will also 'load' the thing as well, so spool-up becomes a second factor.

Right now, at highway speeds,eg: 65MPH I see about 500*to 550*F with about 3-5 psi empty.

My most common range of operating temps is between 450*F and 600*F depending on pedal/grade.

Keeno, you're right about the truck 'feeling relaxed' at highway speed. I kinda notice the same thing too.

When I open it up at 60MPH she hauls apples real nice. It just steps out and goes.

I wonder if 14cm can be polished up internally to help with the high end since thats were the EGT's may become a factor.

Just thinking out loud on that.

Anyway, thanks for kick in on this, hopefully a couple more will give me some input too.



Thanks guys, Bob

 

[bflood]

BushWakr, Where is your pyro sensor, before or after the turbo?

 

[KEENO]

Hey Bush Wakr!



I had thoughts of having a 12cm2 "Extrude Honed" to clean up the interior and possibly open it up to a "13cm2-ish" housing. Seemed pretty expensive and a few TDR Brothers in the know said it was a waste of time & money. No gains to be had!



Neither of our 2 trucks have tachs on them for RPM information... . They're both 1992's.



Here's a deal for you Bush! I you want to try out this Banks 14cm2 I have sitting on the shelf... . it's your's for the price of shipping. It costs about $20. 00 USD to ship a housing across the country. Try it for a few weeks and then send it back if you don't like it. If you decide it's the "hot ticket" for you we'll talk.



Just an offer... . I know it'll be put to good use.



KEENO

 

[KEENO]

Relaxed...

The 14cm2 also feels fairly relaxed on the highway! Not quite as lazy as the 16cm2... . Shall we call it "attentive"? Alert & ready for action w/o being hyperactive.



The 12 is a bit more hyper but that's my choice these days. The turbo whine is "intoxicating" w/ the 12.



KEENO



PS: While you're swapping housings... Dig up an old, discarded 12 from a Second Gen and give it a spin also... .

 

[Bob Beauchaine]

I've got the 14cm wastegated turbo on mine. I put it on after about 15,000 miles - it works great. Highest temp was 1150 after a long hard pull in 4th hauling my trailer with 25lbs of boost. Normal at 70mph, truck only, is 2-5 psi of boost and 500 to 600 degrees depending on driving conditions. All temps are pre-turbo.

Since I had the new pump installed I have not had a long hill climb but temps are down 100 to 150 degrees.



With the new pump I feel a very slight turbo lag due to the power of the pump. It will set you back in the seat quite nicely from 40mph on up to 70.



Happy trails

Bob

 

[JLEONARD]

I just put in a 16 cm housing and I see about the same numbers as Keeno's girl's truck... ... with no smoke. EGT run 500-800 during normal running... with an empty truck.

The highest EGT I have seen during a bonzai run has been about 1100.

bflood... ...

I work in Watertown... if you want to go for a test ride some day during lunch time to compare notes with yours we can do that.

-- email address removed --

 

[KEENO]

Downpipe mod....

Just a reminder that the downpipe will have to be modified to accept the increased length of the 14cm2 wastegated housing. I guess you could always give Piers a call for one of his 14cm2 "NON-Wastegated" housings.



KEENO

 

[BushWakr - RIP]

bflood, my pyro is now mounted PRE-turbo. Wow, what an eye opener, both in temp readings and response.

I can say that for those who are still running post-turbo the old formula of 10*F for every 1 pound of boost added to your EGT reading is about right. Atleast it was for me (up to about 26psi). Based on my post-turbo readings and 'the math' I was seeing about 1050*F on a test grade. Now I see 1100*F on the same hill, with the same conditions. I just got tired of "doing math" while trying to drive.



KEENO, I can't thank you enough for the offer. I may just take you up on that since you housing is wastegated.

Piers has a 14 N/W'd for me thats pretty inexpensive since there's no wastegate, but I DO like the idea of being able to adjust.



I'm having some trans work done next week. Let me see how that goes, my temps, etc. and I'll go from there.

Your offer is VERY much appreciated



Thanks for the input too, you guys. Its tough deciding to change something when you don't know if your gonna make things worse by doing the change. Not all of us can afford to do change after change since $$$ are an issue.



Thanks alot



BushWakr

 

[roadhawg]

I have a 14mm on my truck and see 950 at wot with post mounted piro, but I put a small valve in the line that conects the wastgate to the intake manifold and usually keep the valve closed to help keep egts down. The wastgate was set at 20lbs but temps were in the 1350 range instantly when I would stab throutel. I know most first gens are not turned up as far as this one and will see excllent results with this size housing but if your going for all out fuel get the non-wastgated from the getgo.