About to order parts - Power Adders?

[stratt134]

I have a stock 98 gsx. I am about to order the following from Slowboy:

1) Mits 1G stock BOV - $120
2) SBR Manual Boost Controller - $50
3a) 2G Dejon Upper Intercooler hard pipes (w/ 1G BOV flange) - $200
-- or --
3b) GReddy Upper + Lower kit - $200 (***does this use 1G BOV flange? if so i will buy this instead of Dejon.... let me know***)

I am buying those 3 becuase my stock 100,000 mile car's stock BOV leaks, plus other boost leaks. All that is about $400 worth of stuff - it wil help the car run better, but then I though, if I'm going to spend $400, I might as well spend a little more to get the most bang for my buck as far as more easy power.

Then I found articles on importtuner.com where they took a stock motor and added the following while dyno testing:

A) Apexi downpipe = +36HP/+30TQ ~$250
B) Fuel Pump = +25HP/+25TQ ~$100
C) Straight/Test Pipe = +30HP/+10TQ ~$75

So, are those numbers accurate?? They did a bunch of other tests that only resulted in a few HP, like headers, intake, cam gears, etc. I think I am going to buy the "test pipe" in place of the stock cat... sounds like the best bang for the buck to me, plus easy to instal.

My only concern is with the O2 sensor behind the stock cat.... I'm not worried about passing emisions... anything else I have to worry about? What do you think about this idea before I purchase? Thanks!

Sean

 

[brute]

I'd like to see dyno graphs that back those results. The way I like to see it, most mods don't add power themselves, but allow one to make more power. For example, fuel injectors don't add power, but they allow you to turn up the boost. Boost makes power.

1. A 1g BOV is a very good mod for 2g cars. The 2g BOV cannot hold much more (if any) than stock boost. So the 1g BOV won't add power, but will allow you to turn up the boost when your car is ready. I highly suggest finding one used on the Tuners classifieds, as $120 is nearly as much as any new ones from a "name-brand" BOV.

2. MBC's are good mods as well. You can research the eBay ones on here by doing a search. Many have had success with them, and some have not. They are only like $10-20, though, so it may save you some money in that aspect. You can also look at how to make your own. That's what I did, and it treats me just fine.

3. UICP is a very good mod for 2g's as well (deja vu... it seems someone has actually done their homework!). The GReddy one comes with a GReddy flange, so if you're getting the 1g BOV, I guess this is out of the equation. Dejon makes quality stuff. I also suggest looking for this part on the classifieds. Save money where you can!

The 2nd o2 sensor (the one behind the cat) basically just tests to see if the cat is working properly. You can do a search on the How-To's here or on vfaq and find the way to bypass that o2 sensor so if you take it out, you won't throw a CEL. Buying a test pipe seems like a waste of money to me, since you aren't concerned about emissions. If you buy the apexi downpipe, it eliminates the cat anyway. You can just get a downpipe and catback, and you won't have a cat anymore. If you are concerned about emissions, get a downpipe that keeps the stock cat, get a test pipe, and then get a catback. If you're confused, I can draw up a picture in paint or something, let me know.

Good luck!

 

[DSMnewbie41]

My only concern is with the O2 sensor behind the stock cat.... I'm not worried about passing emisions... anything else I have to worry about? What do you think about this idea before I purchase? Thanks!

Sean

The only thing that could happen is the check engine light coming on. Alot of people use the test pipe and it never happens but mine came on just using a high flow cat. Theres ways around it to turn the light off but in the end all it is is a light.

 

[DSMnewbie41]

Depending on how much money you want to spend... if you are gonna run a new downpipe and test pipe or a cat-delete downpipe you might as well finish it off with the cat-back and give it that nice low purr

plus it will be alot easier to match aftermarket downpipes up with an aftermarket cat-back so that you dont have to make any modifications

 

[matthewdesigns]

The first thing you need to do is get current on all regular maintanence, belts, hoses, fluids, etc.

Second is install an aftermarket boost gauge. Hopefully you've already read that the stock one is crap. Do this before you even THINK of adding a boost controller and cranking it up.

I've done all of what you listed for your car to my '96 TSI AWD with the exception of the pump. Did it in stages, felt the difference in stages, so I can tell you that those hp/tq numbers are pretty generous estimates. I doubt that even after doing ALL of those mods (and more...I've got an EVO316g, too) that my car is making 100hp/70tq more than stock (but I have not dynoed it so maybe it is). So I'd be REALLY surprised if adding a dp/cat eliminator alone gives you those increases (66hp/40tq as noted on your post).

For my money, and actually the way I did spend mine , I'd start with a boost gauge, a new intake/open filter, UICP with 1g or Greddy Type S bov, and a boost controller. You'll definitely feel a difference when you turn the boost up a few pounds and the motor's breathing better.

 

[c4uldr0n]

I have a stock 98 gsx. I am about to order the following from Slowboy:

1) Mits 1G stock BOV - $120
2) SBR Manual Boost Controller - $50
3a) 2G Dejon Upper Intercooler hard pipes (w/ 1G BOV flange) - $200
-- or --
3b) GReddy Upper + Lower kit - $200 (***does this use 1G BOV flange? if so i will buy this instead of Dejon.... let me know***)

I am buying those 3 becuase my stock 100,000 mile car's stock BOV leaks, plus other boost leaks. All that is about $400 worth of stuff - it wil help the car run better, but then I though, if I'm going to spend $400, I might as well spend a little more to get the most bang for my buck as far as more easy power.

Then I found articles on importtuner.com where they took a stock motor and added the following while dyno testing:

A) Apexi downpipe = +36HP/+30TQ ~$250
B) Fuel Pump = +25HP/+25TQ ~$100
C) Straight/Test Pipe = +30HP/+10TQ ~$75

So, are those numbers accurate?? They did a bunch of other tests that only resulted in a few HP, like headers, intake, cam gears, etc. I think I am going to buy the "test pipe" in place of the stock cat... sounds like the best bang for the buck to me, plus easy to instal.

My only concern is with the O2 sensor behind the stock cat.... I'm not worried about passing emisions... anything else I have to worry about? What do you think about this idea before I purchase? Thanks!

Sean

All of the quote HP/TQ rates are extremely overrated, unless they did something like raise the boost level after installing them.

I'd do it in this order:

#1 boost gauge
#2 logger
#3 exhaust work
#4 MBC
.....
After this, decide if you want to keep the stock side mount intercooler or want to go front mount. Then you can decide which BOV you want flanged on the charge piping and which BOV to get.

I say logger, because you want to make sure everything looks good with each upgrade you do....
.....
depending on how much HP you are wanting to go, and if you do turbo upgrades, etc... you may need to rewire your fuel pump (and or replace) + injectors + fuel tuning device, which the logger can help you determine if your injector duty cycle is getting to high.

$0.02

 

[DGajre777]

My only concern is with the O2 sensor behind the stock cat.... I'm not worried about passing emisions... anything else I have to worry about? What do you think about this idea before I purchase? Thanks!

Get the long RRE downpipe which eliminates the cat and get $8 worth of parts from radioshack to fix your check engine light after you remove the cat and rear o2. Check the tech guide for o2 sensor simulator.

 

[dcg9381]

I can't imagine a new fuel pump will add any power at all. For most factory turbo cars, you can get more power by leaning out mixture (at the risk of EGTs and engine damage) vs pumping more fuel.. Fuel pressure should additionally be regulated and it you won't get additional fuel.. Basically, I don't believe the claim of addition HP via fuel pump until you're not flowing enough fuel volume.

 

[c4uldr0n]

that's why I mentioned that the HP/TQ numbers are bogus, unless they turned up boost after installing the new parts.

 

[stratt134]

Thanks for the info. I currently have a aftermarket boost gauge... Then a friend tried to make his own boost controller for me... hooked it up - nothing. Then I just unhooked the hose to the wastegate - same result - nothing over 14psi. When I tried to put it back on the stock plastic controller, the hoses were trash. So I need a new MBC to turn down the boost.... I simply HATE those rubber IC hoses so they are going.

Screw a cat-back or any BS like that, everything I have seen is way over priced. Maybe a cheap logger too......

I think I will go with the cat-eliminating down pipe and see what happens.......

 

[Talesin]

Sorry dude, but those numbers sound like ricer math to me.
25 horsepower due to a new fuel pump?! I mean, sure, if you're running out the stocker it'll help, but that's not really going to happen without some other mods first, or bumping the boost.

And a downpipe/testpipe combo adding 66 horsepower? That right there is BS. They either were raising the boost to get those numbers, or just had some Honda kid writing their blurb.

No way you're going to pull that off. No way you're even going to get *half* that, without a cat-back.
Sure, it adds a little. I might bench-guess around 10-20hp for a full turbo-back exhaust, with no other mods. What it really does is remove a restriction, allowing the car to breathe easier and respond to other mods more noticeably and dramatically. No one part is going to spike your horsepower like that, aside from bumping the boost, and if you do that too much without the supporting stuff, engine goes *toast*.

 

[Ginglingston11]

i have actual dyno sheets for parts and a downpipe and catback combo makes like 13 hp to the wheels and uicp made 15 wheel WOW, and i think an intake made 8, all without changing the boost. Fuel pump no dyno from, but my first mods were fuel pump, boost gauge, and mbc. it pulled hard, i know with the 255 without a AFPR was dumping way to much gas. i would do uicp, turbo back, intake, mbc. if your serious bout the fuel pump then im telling you now, dont put it in unless you have a Fuel Pressure Regulator

 

[nyk4life]

this was taken directly of the import tuners website, they added the parts to 92 talon tsi. i think its BS.

IMPORT TUNER
The Parts
1 APEXi N1 Downpipe $239.00
2 HKS FCD $150.00
3 Holley 255lph fuel pump $251.00
MSRP total $640.00


Conclusion: A two-hour-and-15-minute install netted a total of 106.7 horsepower and 79.8 lb-ft of torque. We only did six small modifications and are still on the stock turbo and that has me curious as to how far we can take the car in street trim.

Performance Chart
HP Level HP+ TQ Level TQ+
B Baseline 183.6 * 198.6 *

1 APEXi Downpipe 219.9 36.3 228.7 30.1

2 HKS FCD 267.1 47.2 252.8 24.1

3 Holly Fuel Pump 290.3 23.2 278.4 25.6

F Final 290.3 106.7 278.4 79.8

 

[DSMnewbie41]

Road Race Engineering makes a real good cat back.. Espelir 80mm thats 3" through and isn't to pricey... you're not gonna see as much of an improvement from your later upgrades if you dont open up all of the restrictions first.

 

[elfroggo]

I think you may need to do more research before going further.

"Then I just unhooked the hose to the wastegate - same result - nothing over 14psi."

First, detaching the boost signal from your wastegate is a great way to blow your motor and turbo. When you do that the wastegate will never open. If everything had been working you would have built infinite boost.

Also, what is the point of getting a higher flow downpipe just to restrict it with stock? If anything move backwards from the exhaust exit. Upgrade the catback before downpipe.

If you're going to buy hard piping, might as well just get the SSAC 2G FMIC kit.

And yeah, if you're going to buy a 1g bov, don't buy it new. Pick it up used for 20-30 bucks.

 

[Talesin]

Hell, I have one or two 1G CBVs sitting in my closet... I'll have to look and see if they're still there, or if I just handed them to 2G buddies to fix the pathetic plastic piece.

Also, putting on a DP/testpipe and (somehow) hooking it up to the stock cat-back would be more likely to lower output than raise it... you lose the scavenging effect the stock exhaust provides, but still have a huge bottleneck further down the line.

Pretty much settles that ImportTuner.com is full of crap... a hundred horsepower gain, from that? Laughable attempt at bench-ricing.

 

[stratt134]

Well, the hose is just a hangin.... yea I know stupid stupid... but now that I am going to fix it... I would like to learn why the car wouldn't boost over 14psi with the boost signal off? "If everything had been working you would have built infinite boost." - What do you think is not working?

Also, the Dejon UICP is like $200, the BOV used is $30.... You say get the SSAC 2G FMIC... how much is that? Is it that eBay thing?

I'm trying to fix bottle necks here... I don't want to fork out for a full cat back, so I thought the test pipe would remove the biggest restriction in the exhaust... thus easy HP.

 

[DGajre777]

I think you may need to do more research before going further.

"Then I just unhooked the hose to the wastegate - same result - nothing over 14psi."

First, detaching the boost signal from your wastegate is a great way to blow your motor and turbo. When you do that the wastegate will never open. If everything had been working you would have built infinite boost.

WTF Removing a pressure source from the wastegate it will make it run at whatever the spring is set for. Removing a pressure source from the wastegate will NOT keep it closed and build infinite boost!

 

[DGajre777]

Well, the hose is just a hangin.... yea I know stupid stupid... but now that I am going to fix it... I would like to learn why the car wouldn't boost over 14psi with the boost signal off? "If everything had been working you would have built infinite boost." - What do you think is not working?

Everything is working the way it is supposed to. That's why your car won't build boost over 14psi, that's what the spring is set for.

Also, the Dejon UICP is like $200, the BOV used is $30.... You say get the SSAC 2G FMIC... how much is that? Is it that eBay thing?

Yes, it was an ebay thing. An entire FMIC with upper intercooler pipe for $300 shipped. There's a guy on here who sells it. Do a seach for ebay FMIC and you'll see the huge thread.

I'm trying to fix bottle necks here... I don't want to fork out for a full cat back, so I thought the test pipe would remove the biggest restriction in the exhaust... thus easy HP.

Check out www.dejonpowerhouse.com for their exhaust systems. Your other alternative is to go to a local exhaust shop and have them make an entire exhaust system. It doesn't make sense to get a downpipe or a test pipe and keep the stock catback. You will not believe how small the stock exhaust piping is compared to a 3" exhaust.

 

[Talesin]

However, given that the stock WG actuator will hold a good bit of boost with no vac/boost source (I'm guessing more than enough to hit the point of geometric growth, when even the WG actuator fully open will not divert enough exhaust to control the turbo) ...in any case, I'd be willing to bet that his engine would pop before that limit would be hit.

As for why you didn't exceed 14psi, my guess would be the leaky-ass 2G stock CBV. Both from boost escaping, and from the over-rich condition that would cause, generating an inefficient burn so you wouldn't get quite as strong exhaust pulses. That or you might have a badass boost leak from hell, like from an uncapped vacuum line just hanging there, venting boost pressure to the atmosphere. Any number of reasons, really.