2G Magnus SMIM?

[megst98]

i want to add some more power for my 2g so i'm looking into doing the magnus smim with the velocity stacks.. what other mods do i need to go with this.

should i get new injectors or wait to do that with the turbo...

should i get a new pump...

should i get the 75mm throttle body?

any answers will help.. thanks

 

[talon96tsi]

If I were you I would worry more about a better fuel system. Pump, injectors, etc. A SMIM would be worthless on the t25 anyway.

 

[Turbocharged]

A SMIM may actually hurt you because you will not be making power in the upper rpms with your setup. Look at my mods. I have everything but a SMIM. Your money would be better spent on fuel upgrades and a bigger turbo.

 

[donmagicjuan]

i want to add some more power for my 2g so i'm looking into doing the magnus smim with the velocity stacks.. what other mods do i need to go with this.

should i get new injectors or wait to do that with the turbo...

should i get a new pump...

should i get the 75mm throttle body?

any answers will help.. thanks

Geez, this one's going to get ugly. A SMIM is usually at the bottom of people's upgrade lists and, as already stated, will not do much for your T25. Take a look at the upgrade paths on these forums to get an idea of the most common mod sequence. The paths you find there have been proven time and again.

Regarding your other questions,

1) Avoid running larger injectors until you have something to tune them with, e.g. an AFC, DSMLink, or other. Running large injectors without compensation will make your engine run extremely rich and can lead to a number of complications. Until you upgrade your turbo you will be fine with stock injectors.

2) You will need to do a fuel pump upgrade when you switch to a larger turbo. If you're already thinking about a SMIM, go for a 255lph and rewire it. Keep in mind you will also need to run an aftermarket AFPR to handle the flow of the larger pump.

3) I'm not sure about the opening of the Magnus, but that will determine what size throttle body you should get. It just doesn't make sense to run drastically different size bores on your TB and IM.

Again, I want to stress that if you decide to perform this mod without first upgrading the turbo and the requisite supporting mods, you will be very disappointed. The T25 runs out of steam long before your stock IM becomes a restriction.

 

[andymoraitis]

Geez, this one's going to get ugly. A SMIM is usually at the bottom of people's upgrade lists and, as already stated, will not do much for your T25. Take a look at the upgrade paths on these forums to get an idea of the most common mod sequence. The paths you find there have been proven time and again.

Regarding your other questions,

1) Avoid running larger injectors until you have something to tune them with, e.g. an AFC, DSMLink, or other. Running large injectors without compensation will make your engine run extremely rich and can lead to a number of complications. Until you upgrade your turbo you will be fine with stock injectors.

2) You will need to do a fuel pump upgrade when you switch to a larger turbo. If you're already thinking about a SMIM, go for a 255lph and rewire it. Keep in mind you will also need to run an aftermarket AFPR to handle the flow of the larger pump.

3) I'm not sure about the opening of the Magnus, but that will determine what size throttle body you should get. It just doesn't make sense to run drastically different size bores on your TB and IM.

Again, I want to stress that if you decide to perform this mod without first upgrading the turbo and the requisite supporting mods, you will be very disappointed. The T25 runs out of steam long before your stock IM becomes a restriction.

Nicely said Don...

 

[daren_p]

Don hit it right on, a SMIM should be one of the last items on your list. They don't start to make more power compared to the stocker (and in most cases lose bottom end, the only spot the t25 has power) until about 5000+ rpms, the t25 will run out of steam way before this. Cams are usually recommend before a SMIM but once again these are designed (depending on which grind you choose) to make more power in the upper rpms, which once again is usless with the t25, which can't even keep up to the stock setup in the upper rpms. Get all the supporting mods first, then the turbo, then get a set of cams and if you still feel you need more power in the upper rpms & want to increase you redline to get the full benefit, then get a SMIM.

 

[megst98]

wow.. thanks for all of the feedback everyone...

well for the turbo setup...
i wanna run a 20g or 18g...
i have the tubular manifold setup for an external gate already so i can just throw a 38mm tial on there with a dump.
then i was lookin at like 660 injectors and the 255lph pump with an afpr..


should i get a fuel rail to go along with it?
let me know...

ohh and will i have to do the clutch for the turbo upgrade.

 

[Boosted98gsx]

You need to be buying fuel and tuning mods before you purchase even a new turbo.

I recommend DSMlink, a walbro225hp, 1000cc injectors, a wideband, GM MAF + T, & GM 3.3bar MAP. Why would you want to run a $1200 20g, when you can get a bolt-on 50 trim for $800?

 

[megst98]

well i need the turbo that im gonna get to have the same exhaust mani flange and the same o2 housing flange b/c i have aftermarket ones and i want everything to bolt up the same... so what 50 trim should i get..

i think 1000's are a little overkill and i dont think i can run a wideband b/c i have a dump...

do you need a laptop with the dsmlink.?? i never really read into it too much but what would i need

 

[donmagicjuan]

well i need the turbo that im gonna get to have the same exhaust mani flange and the same o2 housing flange b/c i have aftermarket ones and i want everything to bolt up the same... so what 50 trim should i get..

i think 1000's are a little overkill and i dont think i can run a wideband b/c i have a dump...

do you need a laptop with the dsmlink.?? i never really read into it too much but what would i need

Not sure about the turbo, but you will still be able to run a wideband O2 sensor regardless of your type of wastegate. Just replace the rear sensor with the wideband for the easiest approach. Yes, 1000cc injectors would be overkill for the type of power you're looking to make. Not to mention you would have a hell of a time tuning with them without DSMLink or something similar. An AFC just wouldn't cut it with something that large. I'm running ECU+, which has very comparable feaures to DSMLink, and it requires either a laptop or both a palm pilot and a desktop to interface with the ECU. If you have the funds, I would highly recommend a system like this that allows you to adjust fuel and timing curves independently. When compensating for injectors >660-720cc, it's just about a necessity.

 

[Boosted98gsx]

You can use DSMlink with a Palm as well. Plus DSMlink has the support for the coding for virtually ANY 5v input you want; EGT, Fuel pressure, Boost (Via MAP sensor), Wideband, and when v3 comes out, you will be able to run a GM MAF without the translator so no more whacked out airflow readings.

 

[donmagicjuan]

You can use DSMlink with a Palm as well. Plus DSMlink has the support for the coding for virtually ANY 5v input you want; EGT, Fuel pressure, Boost (Via MAP sensor), Wideband, and when v3 comes out, you will be able to run a GM MAF without the translator so no more whacked out airflow readings.

Good plug. ECU+ does all of this, too.

 

[Boosted98gsx]

Yet, ECU+ is still just a piggyback, that's actually MORE expensive than DSMlink...

 

[donmagicjuan]

Yet, ECU+ is still just a piggyback, that's actually MORE expensive than DSMlink...

Uh, I don't think this is the right place for a pissing contest about which engine management system is better, but since when is DSMlink not a piggyback? Does it still not use the ECU's fuel and timing maps by offsetting the MAS and CAS signals? And the last time I checked, they were comparable in price. If you feel so strongly about the subject, start a thread to debate the two. This one is on the topic of SMIMs.

 

[donmagicjuan]

Thanks for clearing that up. I am by no means an expert on DSMlink, so it's interesting to see that it works a little differently. While ECU+ does alter MAS signals to dial in AFRs, I believe when you scale your injector sizes it somehow compensates for the additional timing you would see by heavily altering the signal. For instance, I still only see ~18* of timing at the top of a pull with no additional adjustments to timing and with 560cc injectors. But it sounds like the operation of DSMlink is a little better suited to running enormous injectors.