Engine/Transmission (1998.5 - 2002) Mach 3's vs Mach 4's

[Clmsnow]

Aside from the 15hp difference, what is the difference between the 3's and 4's?? I don't understand why they would make injectors that are so close in hp rating to each other. Is the design much different or do EGT's really change that much between the two?? Why would someone rather have one vs. the other? I know some will say, for the same money might as well get the extra hp, but just trying to figure this out. Thanks.

 

[Supermod56]

Dunno, but I know most guys use the 4's, that's what I'm going with when funding allows.



Tom

 

[Fishin Guide]

Aside from the 15hp difference, what is the difference between the 3's and 4's?? I don't understand why they would make injectors that are so close in hp rating to each other. Is the design much different or do EGT's really change that much between the two?? Why would someone rather have one vs. the other? I know some will say, for the same money might as well get the extra hp, but just trying to figure this out. Thanks.

I have had the M3s and the M4s. I made the switch not out of neccesity, but because I sent back the M3s to Don to check out. I thought I possibly had a bad injector, which was not the case, and Don sent me some M4s in thier place.



The M3 is an awesome injector. Less smoke than the old DD2s and made 388 with an EZ.



The M4s are even better. Less smoke than the M3s and very driveable. I do not know this for sure, but I believe the M0-M3. ? are all the same series of injector. The M4s and bigger are another group.



Anyway, I love the M4s and the little bit of 15hp spelled out a smoother running, more linear feel. The M3s felt like they had a "hit" kinda like a two stroke getting on the pipe. But the M4s are pure gravy. Deceptively powerful, I have to watch that speedo to make sure I am staying legal. With the DDUFM on kill, I get very little smoke unless I mash it from a light and only a haze after boost comes on. My temps are very controllable and hitting 1250 mean I am doing well over 90 and the temps are not climbing very fast.



Dave

 

[dsather]

Dave,



That's interesting. I've got Mach 2's and am thinking about stepping up a little to 3 or 4. Did anyone explain why the Mach 4 would smoke less that the previous 3 you had? Of course, if the 3's (like my 2's) are a little older then probably spray angle enhancements. Any other info you have about the 4's would be appreciated. Idle, cruise control steady, smoke at start, etc.



Thanks

Dennis

 

[OPoole]

The Mach 4 is a great everyday injector has a Newer tip design than the mach 3s. Mach 4s have less smoke than 3s with more power.

 

[Graphic man]

I wonder if a Mach 5 or 6 could be used as an everyday driver????

i hear a lot of good things about the 4's

 

[HeavyHauler]

A buddy is running Mach 6s with a full size B1 single right now. Temps are staying cool and he says the thing drives better than when we had the Mach 3s in with the B1.



With the turbos out now, I think running 5s and 6s with a larger single is very possible for a daily driver.

 

[Graphic man]

I am hearing a lot of good things about this new SPS66 turbo! it's either a a SPS66 or a B1-2

and maybe a set on Don M's 4's or 5's

 

[Hohn]

With the turbos out now, I think running 5s and 6s with a larger single is very possible for a daily driver.

I'd second this. Based on how docile the 4s are, I seen no reason why you couldn't. I'm running my 4s on a stock charger, and driven sensibly, there are no issues (aside from traction probs, lol).



You should be able to daily drive 5s and 6s with a larger turbo like the SPS66.



Note: don't turn loose your mom in your hot-rod truck, after a little rain. She was spinning the tires in 5th

 

[DHayden]

Not hijacking the thread but I read of 5's and 6's not giving much more power increase on the HO's. Is this still true? Why was/is this happening and is there any way to get the full power out of them?

 

[PC12Driver]

The HO pump is just simply running out of fuel.

 

[RJPotts]

Correct, The plungers in the HO pump are smaller than the SO pump, this makes more power from the factory and makes more power, easier than the SO up to a certain point, but at that point the smaller plungers can't supply any more fuel to the injectors, and the SO pump can.

-R. J.

 

[Clmsnow]

So basically, go with the 4's. Doesn't seem like there is any reason someone would buy the Mach 3's.

 

[mcoleman]

Go with the 4s. And there is more difference than 15hp. The 3s are 125hp and the 4s are 150hp. I just upgraded to 4s Saturday and wish I would have done it sooner.

 

[Hohn]

Correct, The plungers in the HO pump are smaller than the SO pump, this makes more power from the factory and makes more power, easier than the SO up to a certain point, but at that point the smaller plungers can't supply any more fuel to the injectors, and the SO pump can.

-R. J.

Yes-- 7. 5mm plungers on the SO vs 7mm plungers on the HO.



The 5s and 6s can make power on an HO pump-- they just won't make more measured HP on the dynojet.



If you're pulling or running any drugs (especially nitrous) then you WILL see a performance increase with the 5s and 6s, even on an HO pump.

 

[darkhorse]

Yes-- 7. 5mm plungers on the SO vs 7mm plungers on the HO.



Smaller plungers in the injection pump & smaller injectors, yet the ETH makes more power?! What besides the higher compression makes that happen?

 

[PC12Driver]

The pump on the ETH is designed to run at higher pressures than the ETC at the stock power level (smaller diameter plungers, longer stroke). The higher pressures and the smaller injectors will make for better atomization of the fuel, which will burn more quickly and efficiently. They're probably squirting a larger volume of fuel too, and the higher pressures are there to help with emissions control (less smoke/soot).

 

[Hohn]

Yes-- 7. 5mm plungers on the SO vs 7mm plungers on the HO.



Smaller plungers in the injection pump & smaller injectors, yet the ETH makes more power?! What besides the higher compression makes that happen?

Aside from that, it's just software. The HO is programmed to use more of its potential in stock form.



So, if 63% is max fueling of the VP, then the SO might use 30% in stock form, and the HO might use 38% (fictional numbers).



Thus, there's less "untapped" potential (pardon the pun) with a fueling box on an HO. That's why a Comp that gives an SO 120hp or more, only gives an HO about 85hp-90hp. The HO just has less potential, and it's using more of it smaller quantity in stock form.



In stock form, think of the SO as a bodybuilder benching only 150lb when he COULD bench 500+. Think of the HO as a smaller guy benching 180lb, when his max is only 300 or so.



One is clearly operating closer to his limits.



jlh

 

[OPoole]

Mach 4. 5 after that no more power from the HO

 

[Clmsnow]

Mach 4. 5?? I thought there was a 4 or a 5... what is the 4. 5?? I have heard of people talking about 3. 7's in the past as well.