Engine/Transmission (1998.5 - 2002) Mach 4 ?????

[AHire]

I want to buy either Mach 2 or Mach 4, but If i go with Mach 4's will egts become an issue? Im running a stock turbo(hx35) with blocked wastegate. I am also planning to purchase a smarty.



I do tow around 14000# from time to time.



Anyone running this setup or similar?

 

[darkhorse]

I want to buy either Mach 2 or Mach 4, but If i go with Mach 4's will egts become an issue? Im running a stock turbo(hx35) with blocked wastegate. I am also planning to purchase a smarty.



I do tow around 14000# from time to time.



Anyone running this setup or similar?

I suspect you will get a little toasty if you have a heavy foot with that big load. I'd definitely advise reactivating your wastegate. Also, if you have the 12 cm turbine housing, swap it for a 14. You can get by with Mach 4's & a stock turbo but you can't push it hard.

 

[AHire]

I do plan on upgrading my turbo in the future. I drive by my pyro towing it has never been over 1100.



I dont want to get the mach 2's if i can baby the 4's until i get a turbo.

 

[darkhorse]

Go for the 4's you won't be disappointed! Oo.

 

[AHire]

what is he difference in the 4's and the 3. 8's that you have?

 

[darkhorse]

Nothing you could feel with the seat of your pants. They are slightly undersized with the intent of making EGT's easier to control. It's a special set Don had made up at the time, I guess to experiment with. I was in a thread on NWB about Mach 4's & he offered them to me as a bout perfect for my needs. btw, he said that the HO VP44 is maxed out with Mach 4. 5's

 

[Midnite]

Darkhorse, don't the Mach 3. 8s have a slightly different spray angle than the 4s? I thought I'd read that somewhere, but I may be wrong.



Mike

 

[darkhorse]

Darkhorse, don't the Mach 3. 8s have a slightly different spray angle than the 4s? I thought I'd read that somewhere, but I may be wrong.



Mike

You might be thinking of the older 3. 75's. The ones Don sent me are just undersized 4's.

 

[Hohn]

I want to buy either Mach 2 or Mach 4, but If i go with Mach 4's will egts become an issue? Im running a stock turbo(hx35) with blocked wastegate. I am also planning to purchase a smarty.

I do tow around 14000# from time to time.

Anyone running this setup or similar?

You'll have enough fuel with the M4s to grenade the charger with a blocked WG.

I'd run the 4s, knowing full well that you could damage the engine if not careful. Be extra conservative on the EGTs, and downshift early and often.

14K is heavy for M4s and stock charger. Just limit yourself to 60% pedal or so and you'll be fine.

If you don't respect the M4s, you will melt your engine and have a rather expensive repair bill.

Having had the 4s now for about 6 months, I'd never consider the 2s. But I don't tow... .

 

[rivercat]

I just wanted to add that my 4s never ran RIGHT till I taped the wire with the comp.

Smoke is non existant in normal driving and it smoothed the whole powerband out allot once I found the right setting 3x2 for daily driving/ heck on 5x5 they hardly smoke at all if I keep the charger lit and with a good roll into it I can only get a light haze.

with the box off its allot of smoke at the bottom and kinda rough all the way up...

I would say from expirence that the heat /smoke/lag on the bottom of a truck running the HX 35 comes from the choked up elbow. And that with a 14cm housing and a mega mouth one could stand to run 4s ok without too much heat. ---- JMO

 

[darkhorse]

Rivercat, my 3. 8's ran smooth as glass with the box off. I wonder if the difference is in our turbos.

 

[Hohn]

My 4s have been smoooooth since day one.

This is with stock electronics, then a VA, then a Catcher, and now Smarty.

 

[c-hawk]

I agree with the others that said there 4's are smooth.



My 4's were about the smoothest injector i've ever experienced. Even my 7's are noticeably smoother then the little dd2's i had at one time.



If your truck is running rough i would guess something isn't quite right.



Chris

 

[RonA]

I've been running 4's in my truck for about 1k miles. They are the smoothest, best idling injector I have tried so far(7th set). Unfortunately they are a bit big for a daily driver , and a bit small for a dyno set. I am going to go a bit bigger. If anyone needs a set of mach 4's with 1k miles, let me know and I'll save you a bit of money.

Ron

 

[RonA]

Sorry guys. I am running a p-pump conversion. They push a bit more fuel through than a stock vp-44 with no enhancements. I can't control the fuel on the bottom quite as easily as you guys can with all your boxes and gizmos. 4s work great for a vp44 daily driver. I just have to be too carefull with the pedal when I go to the big city. One of several downsides to living in sunny CA.

 

[AHire]

You'll have enough fuel with the M4s to grenade the charger with a blocked WG.



I'd run the 4s, knowing full well that you could damage the engine if not careful. Be extra conservative on the EGTs, and downshift early and often.



14K is heavy for M4s and stock charger. Just limit yourself to 60% pedal or so and you'll be fine.



If you don't respect the M4s, you will melt your engine and have a rather expensive repair bill.



Having had the 4s now for about 6 months, I'd never consider the 2s. But I don't tow... .

Thanks for the info to all that has replied!



I dont tow alot mostly a skid steer loader or a 20' landscaping trailer with three john deere 72" mowers.



I plan on putting the elbow back on the turbo when i get injectors.



What kind of damage besides blowing the turbo should i be aware of? Cylinder washing?



I try to keep my rpms up when towing. I have babied this truck i guess you could say. Never seen over 1100 on the pyro towing and even thats rare.



I just dont want to get in way over my head.

 

[Hohn]

Thanks for the info to all that has replied!

I dont tow alot mostly a skid steer loader or a 20' landscaping trailer with three john deere 72" mowers.

I plan on putting the elbow back on the turbo when i get injectors.

What kind of damage besides blowing the turbo should i be aware of? Cylinder washing?

I try to keep my rpms up when towing. I have babied this truck i guess you could say. Never seen over 1100 on the pyro towing and even thats rare.

I just dont want to get in way over my head.

A good injector won't wash the walls any worse than a stock injector.

The main risk besides blowing the turbo is excessive EGT. If you gamble on EGTs, you'll lose. PLenty of guys have towed all day with 1300° on the pyro and melted a piston thinking they were safe.

You need to make sure the HOTTEST cylinder is within spec. usually this is #6, but it can also be #1 I've heard.

Anyway, if you keep it at 1100 or less and accelerate gently, you should be perfectly safe.

I'd tow with my truck, but only if *I* was driving.