ALH Colt Cam Lower EGTs?

Motohead1

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Searched around but didnt find what I was looking for. Those that tow or have a an ALH in a heavier swap (+4000lbs) did a colt cam stage 2 lower your sustained cruise EGTs?
 

Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
HECK YEA, it will easily drop the temp 100F across the entire rpm range, provided you have head work already done (port polish etc).
highly suggest a DIY water injection. If your interested i can PM you a parts list and a few links to help with doing a water injection for under $200.
 

Kerma_tuned

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Jan 31, 2018
Location
Edmonton,Ab Canada
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2002 jetta tdi alh
HECK YEA, it will easily drop the temp 100F across the entire rpm range, provided you have head work already done (port polish etc).
highly suggest a DIY water injection. If your interested i can PM you a parts list and a few links to help with doing a water injection for under $200.
How will they perform with out head work. Ive got a stage 3 colt cam on order for my alh with no porting or polishing done yet
 

Mongler98

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That i do not know off the top of my head. A cam works by helping other mods. by its self, with no other mods on a stock engine, it does very little. What it does do is help that torque and HP curve creep up a bit further in distance on the graph and help extend the rpm range within that curve. If you have a bigger curve than the cam multiplies that more, hence it helps out your mods big time vs a stock setup.
If you dont get a tune to go with that cam, your wasting your money. Other things can solve your issues of high EGT,s low HP etc... a cam is always installed after lots of mods and usually some head work, then it shines gloriously. Lets put it this way. i ran 215HP on stock internal block a ported head with undercut valves, big turbo, and big big power injectors and a water injection system and never had issues with temps. all that with no cam.

You should give Kerma a call and talk with them about this, same with Mark Malone. Im not an expert on cams but there are other veteran members here who are. I think they will all say the same, "why"
 

crazyrunner33

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Charlotte, NC
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'10 Golf(bought back)
What kind of EGT are you seeing? I wouldn't be concerned about the EGT too much unless if you're holding over 900 degrees science for a very long time. The bigger concern should be coolant temperature.
 

Mongler98

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1600+F EGT? thats way WAY to high for the stock turbos. Technically it can handle those temps but realistically its more like 1450 max. big 10/4 on the coolant temps.
If your hauling, you need gauges. nothing worse than doing things with out data, especially putting an expensive and fairly pointless mod like a cam on a stock engine.
 

PB_NB

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1999 New Beetle
We didn't do any porting but did a bunch of upgrades with a focus on moving air with as little restriction as possible without breaking the bank. I don't have an EGT gauge but am looking at getting one. That's why we added the stage 2 cam.

I do notice that the power band has shifted to higher rpm's. When we are towing, I try to keep the speed around 60mph when cruising. Our trailer creates a hugh wind drag due to its shape and the car is so small so it doesn't break the wind for the trailer.

I usually keep it in 4th gear and let the rpm's run around 2,600 or so. With our hilly roads that seems to work the best. When in 5th, I need to push the rpm's up or it seems to be lugging and leads to running too fast to be safe with the trailer in tow.

The trailer weighs about 2,000 lbs. which the car doesn't seem to mind. I think the shape creates the biggest drag on the system.
 

TDIMeister

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Anything that opens the exhaust valve earlier up the expansion stroke will not reduce EGT but rather raise it. If there is a real reduction, it's due to some other factor(s), most likely the higher volumetric efficiency from the combination of cam and head porting that means effectively operating at a leaner lambda for a given amount of fuelling. Now that will materially reduce EGT.
 

vwdsmguy

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Syracuse, NY
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2002 Golf black 5-spd
Colt stage 3

I had one of these which was timed properly, but what I didn't like was lower fuel mileage and less power in the normal driving range 1800 to 3000. It had a little more on top, but my 1/4 times were not improved at all. I was luck to sell it for a reasonable price.
 

Mongler98

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Anything that opens the exhaust valve earlier up the expansion stroke will not reduce EGT but rather raise it. If there is a real reduction, it's due to some other factor(s), most likely the higher volumetric efficiency from the combination of cam and head porting that means effectively operating at a leaner lambda for a given amount of fuelling. Now that will materially reduce EGT.
This
its all about flow, If you have a larger intercooler than this will help lower EGT's greatly but on stock, its not going to do much. Im not sure why you have "high"egts to begin with on a stock system? you need gauges and logs to get a better handle on what you need for your application.
 

Motohead1

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charlotte
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Let me preface all thats been said with the setup. Stock ALH, R520 injectors, BV43a turbo,tuned, pushing a 4200lbs truck down the hwy @ 70mph I see sustained 1100F EGTs. Coolant never goes above 208F (ecu) and only gets that warm if its summer and loaded and EGTs pop above the 1350F level. Intercooler is decent sized but could be bigger. I am in the process of putting a much larger cooler on soon and it sounds like it might be what Im looking for. I was just curious if a colt cam might be worth it. I still might do one later down the road.
 

john.jackson9213

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Miramar, Ca. (Think Top Gun)
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Motohead1,

Strongly suggest you listen to TDIMeister. He has a VERY strong high level diesel engineering background.
I also witnessed a comprehensive cam test at a SoCal Dyno day a couple of years ago on a modified B4. Results, cam timing changes and a cam change with the Colt Stage 2 from a stock cam. Results were statistical no change

I have a Jeep Comanche mid size truck just finished with a TDI engine conversion. So EGT temps will be a priority for me also. Hope to post my experience before too long
 
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Mongler98

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OK, well your coolant temps are fine and so are your EGFT, 1350 is nothing to be concerned with, once you pop into the 1450+ thats when you get worried.
Squirt some water injeciotn DIY into it and be done.
 

Mongler98

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98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
Another thought here. Your running R520's on a stock fuel system? those injectors are way to large for your set up. pp764s or smaller would be better considering you have a bolt on turbo and stock exhaust. To make your system work with those injectors, you need bigger turbo, upgrade IC water to air or FMIC and increasing your volume of the IC by at least 30% from the stock volume, exhaust manifold work, up your PSI a bit perhaps and most of all a upgrade on your fuel pump if you have one. Walbro is great pump here. Also the biggest issue is you need an 11mm pump and preferably a 12mm head.

I mean you dont have to use these mods but those injectors are a waste of your money otherwise. A cam will also be a waste if you dont do the following to your engine. Port polish on the head with valve work and upgrade springs, larger or up the psi on your BV43a and upgrade your fuel delivery. your going to be working at higher RPM's and without the supporting fuel delivery and air flow, not to mention the all important retune, you might as well give my disabled son the money or throw it down the toilet.
 

TDIMeister

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More air is the simple ticket to lower EGT. At part-load, steady state, you can map a little bit more requested boost and that will bring your EGT right down. No issues with R520s with rest stock fuel system as long as durations are being kept short and you have the turbo sized properly, but this mainly affects full-load. There are many variations of BV43A but in the end it's still equivalent to a GT17V, ie on the small side for what should be capable of ~200 crank HP given the R520 used. Would be good to also measure and compare EMP and MAP simultaneously. BV43D or GTD1752VRK would be better.

Water injection makes a big difference to EGT, and requires very little quantity to achieve it. But you'd want to use it only at near-full load acceleration, not in steady cruise, or you'll never have a big-enough reservoir. Inject too much and smoke goes up, efficiency goes down.

A cam should be completely off the table if you want to maintain low-end torque for a 4000# vehicle.
 

Motohead1

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Yea Im not doing water injection. Thats more for a short burst WOT track day car. I had a setup on a DSM back in the day before big cheap intercoolers. It did a keep the intake nice and clean though.

I want to keep my low torque down low for sure. The R520s are fine with the 11mm pump and a dodge 12 valve intank pump and no more than 26psi out of the BV43a at WOT.

Thanks for the input guys I will continue with a larger cooler install and go from there. It may be all im looking for.
 

Mongler98

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Yea Im not doing water injection. Thats more for a short burst WOT track day car. I had a setup on a DSM back in the day before big cheap intercoolers. It did a keep the intake nice and clean though.

I want to keep my low torque down low for sure. The R520s are fine with the 11mm pump and a dodge 12 valve intank pump and no more than 26psi out of the BV43a at WOT.

Thanks for the input guys I will continue with a larger cooler install and go from there. It may be all im looking for.
What orifice did you run and what set up was it, i run a preturbo and post turbo 0.02" orifice off my auber gauges of distilled water and i can drive 60 miles each way to an autocross event, compete and get home on about .5 gallons of water. I hammer on it hard too driving home.

with a fine tuned set up i have no issues driving all day long. its only on when i get up in EGT, on at 1400 and off at 1200F and only at least at 15 psi, i run 32 psi so its on at 20 and off at 15. it only needs to to cool off the egt's 2nd stage is on at 1475F and off at 1200.

at 100PSi, i run about 45 psi so say half, the injectors consume 1.9 GPH and that stage 2 rarly comes on but on hard up hill pulls going WOT. how often do you see temps past 1400F? now count how long they stay like that. now do the math. you consume next to nothing.

https://www.mcmaster.com/#catalog/124/2150/=1bg221h
 

TDIMeister

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Larger IC will do squat for you as your high EGT is at part load where there should not be appreciable boost. Just ask for an ECU file that requests 10% higher MAP at part load.

Make sure also that the injection timing is not retarded.
 
Last edited:

smelly621

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Sonoma County, CA
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2001 Golf, 2003 Tacoma
Timely question, I wondered about this too with my swap. My truck is similar @ 4100lbs last time it was weighed, and I am running PP764s nozzles on an 11mm pump.

Since I already had a Franko6 stage 2 cam in my Golf, I decided to swap the cam and lifters between the truck and the Golf a few weeks ago when I had the truck motor out for my engine mount re-do.

I can't argue with TDIMeister's explanation - but the cam did result in slightly lower EGTs across the board, with the biggest decrease coming in the higher revs ~3000-3500 rpm. Steady state on flat highway we're only talking 25F lower, but up steep grades I noticed 50-75 degrees cooler EGTs that I was used to.

It's not earth shattering, and if I had spent $300 on a cam and $80 for lifters to replace a perfectly good stock cam I would be disappointed. However, since I had it already it made sense to put in in the engine with the bigger turbo, PD150 intake manifold, and the ported head (exhaust only) vs. the stock breathing in my Golf.

I also don't feel like my low end power has suffered appreciably in the truck, nor improved in the Golf now that it's sporting a stock cam.

I do wish there was better consensus on what is a safe sustained EGT for the motor, not just the turbo. I start to wonder when the head and pistons are going to change shape and cause bad things. Maybe they are not of concern since they're cooled with oil/coolant and the turbo will be the first thing to go?
 

All Stock

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I found that moving the torque up worked better for a heavier vehicle. Mine was in a loaded wrangler (bumpers, winch, full size spare, etc) If your Dakota has a NV3550 in it you have a close ratio first gear anyway. The key is to make sure its geared properly.

If your going to rely on the torque down low to move the heavier vehicles I strongly suggest you ad rod bearings to your maintenance schedule. If you think I am kidding and you have 10k on your fresh new bearings...pull one and you will see... or should I say you might not like what you see..

The low rpm torque is fun, it makes for giggles, smiles, you know... that giddy feeling... But in reality there is not enough bearing surface area to be lugging it around. Rpm adds the oil volume and pressure that is needed to keep those bearings alive when you consider the higher torque output weighed against the higher loads hanging on the back side of the crank. The tdi is more than capable of surpassing the shear limits of your oil at low engine speeds.
 

Motohead1

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Jul 16, 2016
Location
charlotte
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2002 bug+telephone pole
What orifice did you run and what set up was it, i run a preturbo and post turbo 0.02" orifice off my auber gauges of distilled water and i can drive 60 miles each way to an autocross event, compete and get home on about .5 gallons of water. I hammer on it hard too driving home.

https://www.mcmaster.com/#catalog/124/2150/=1bg221h
It was a shurflow garden pump at 100psi. Caint remember anything else but Im sure its on dsmtuners somewhere.

Larger IC will do squat for you as your high EGT is at part load where there should not be appreciable boost. Just ask for an ECU file that requests 10% higher MAP at part load.

Make sure also that the injection timing is not retarded.
So flat ground little to no load I measure 25 to 30 F IAT above ambient. no MAF and MAP sensor is mounted on the PD150 intake. I think if I can get 10 to 15 F above ambient it should make a noticeable difference especially in summer. my injection timing is just a hair above the middle line in VCDS. I havent played with moving it around yet.

Timely question, I wondered about this too with my swap. My truck is similar @ 4100lbs last time it was weighed, and I am running PP764s nozzles on an 11mm pump.

Since I already had a Franko6 stage 2 cam in my Golf, I decided to swap the cam and lifters between the truck and the Golf a few weeks ago when I had the truck motor out for my engine mount re-do.

I can't argue with TDIMeister's explanation - but the cam did result in slightly lower EGTs across the board, with the biggest decrease coming in the higher revs ~3000-3500 rpm. Steady state on flat highway we're only talking 25F lower, but up steep grades I noticed 50-75 degrees cooler EGTs that I was used to.

It's not earth shattering, and if I had spent $300 on a cam and $80 for lifters to replace a perfectly good stock cam I would be disappointed. However, since I had it already it made sense to put in in the engine with the bigger turbo, PD150 intake manifold, and the ported head (exhaust only) vs. the stock breathing in my Golf.

I also don't feel like my low end power has suffered appreciably in the truck, nor improved in the Golf now that it's sporting a stock cam.

I do wish there was better consensus on what is a safe sustained EGT for the motor, not just the turbo. I start to wonder when the head and pistons are going to change shape and cause bad things. Maybe they are not of concern since they're cooled with oil/coolant and the turbo will be the first thing to go?
Good info thats the real world comparison I was looking for. My main concern is also for the other components and longevity. The turbo is fine.
 

Motohead1

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Joined
Jul 16, 2016
Location
charlotte
TDI
2002 bug+telephone pole
I found that moving the torque up worked better for a heavier vehicle. Mine was in a loaded wrangler (bumpers, winch, full size spare, etc) If your Dakota has a NV3550 in it you have a close ratio first gear anyway. The key is to make sure its geared properly.

If your going to rely on the torque down low to move the heavier vehicles I strongly suggest you ad rod bearings to your maintenance schedule. If you think I am kidding and you have 10k on your fresh new bearings...pull one and you will see... or should I say you might not like what you see..

The low rpm torque is fun, it makes for giggles, smiles, you know... that giddy feeling... But in reality there is not enough bearing surface area to be lugging it around. Rpm adds the oil volume and pressure that is needed to keep those bearings alive when you consider the higher torque output weighed against the higher loads hanging on the back side of the crank. The tdi is more than capable of surpassing the shear limits of your oil at low engine speeds.
Yea I am running the stock NV3500 with 32 inch tires with 4.56 gears. drives great and no lugging at all now. It was not that great when it had the stock 3.55 gears. 5th gear was unusable.
 

All Stock

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NV3550 and 4.56 on 32-33's is a perfect combo. I started with 4.10s on 33's and it wasn't enough gear. It was ok but not ideal. I went 4.88's as I will go with 35's as it goes back together... and 4.56's weren't avail when I did it. The tdi sheared rear R&P teeth in the middle of the desert, literally! Even the 4.88 gears on 33's work very well, I just feel I could drop 100 rpm at 70 mph. Its a common gear to use for the 4 cylinders to give them comfortable highway abilities instead of constantly down shifting. The tdi can use less... hence the 4.56 being ideal. Now how you drive it will determine bearing life.
 
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