Lots of questions (even searched before registering!)

[Trinten]

Hi everyone.

My Fiero currently has a 350ci vortec engine in it that's carb'd. It's being upgraded to a 355 with all forged internals, flattop pistons, running about 10.5:1. My builder estimates it'll be around 430 HP and 400 torque.

Once he's done, I'm going to be switching it over to fuel injection, using the Stealth Ram intake, and an "EFI Connections" 24x Coil Near Plug retrofit including drive by wire throttle body, which will all be controlled by the 411 PCM.

I've done alot of reading on nitrous systems from different places (including here), and alot of it seems to be a matter of preference.

Since my intake/efi system is sort of cobbled/custom, I didn't know what the best, safest, route for nitrous would be. I've got a manual transmission, so from what I've read, that can play into it too.

I've seen a few guys blow up their engines and/or intakes from nitrous incidents, and I don't want that to happen!

So besides delivery system, I could use some help/suggestions in understanding and picking an activation system (it seems the pedal switch method might be best?)

Also, since the car is fairly light, what are your opinions on dual stage systems?

Thank you!

[Vitamin E]

IMO a DPI single wet stage and blow the crap out of it!

[Trinten]

Hi Vitamin E,

Okay, so you think going with a Direct Port system would be the best delivery method, what about activation methods?

It seems like the "RPM window" would be *worst* for me because of the manual... that leaves the TPS, the pedal switch and a push button (aren't those last two pretty much the same thing, just mounted in different places? would that be what the microswitch is?)

[Vitamin E]

The window switch is a safety part. The micro switch with a rpm window switch IMO is the safest and easiest way to do things. You can focus more on driving like you normally would and the nitrous will come on and go off without any help from you.

[Robert56]

Hi Vitamin E,

Okay, so you think going with a Direct Port system would be the best delivery method, what about activation methods?

It seems like the "RPM window" would be *worst* for me because of the manual... that leaves the TPS, the pedal switch and a push button (aren't those last two pretty much the same thing, just mounted in different places? would that be what the microswitch is?)
What happens on a manual with out a WS is the RPMs can hit the limiter real easy. The nitrous will make the rpm climb fast, I mean real fast. that's how i blew a hole in my intake with out a WS, I missed a gear and RPMs skyrocketed into the limiter and mine pulls fuel and once I resumed had a high rpm lean back fire. A ws is must just like a WOT sw, imo. Just another safety factor. Also the lower rpm you spray, the bigger chance you have to do damage to your motor, most limit the low on RPM to about 3500rpm. So it's best to only spray at WOT and at your chosen RPM window. then there are other things like fuel pressure safety sw in case your pump fails or a noid fails.
Robert

[Trinten]

Hey Robert,

Thanks for the information! Out of all the kits I've looked at (unless I'm getting the terminology wrong?) they all seem to only come with one activation method or another... I haven't seen any that have both a switch and an RPM window, is it tough to rig in both triggers?

Also, the reason I thought an RPM window switch was bad (from another thread that I thought I read on this forum) was sometimes when the RPM drops, such as between shifts, the nitrous doesn't stop flowing fast enough, so you get backfire. I take it that's mostly superstition?

[Vitamin E]

The rpm window switch (along with anything else you may want to add) is usually bought afterwards outside the kit. The kits usually come with a micro throttle switch.

I think you'll find that there are more myths floating around about nitrous than true facts.

[Robert56]

I agree. there are so many WS's to chose from that may or may not be what your looking for, some have dual stage control, some have gear lock outs, some have both some have even more options included. but the main reason they are not included is to keep the price down of the kit as many guys go from kit to kit and have a WS already.

You can spray thru the shifts if your tranny is built for it, but you still want it to stop before rev limiter. I have over 300 passes on my 6-speed and have never sprayed thru the shift and have had no back fires at all, however, I am a dry kit only user. maybe the wet guys are igniting the puddled fuel that can happen from fuel drop out on the front entrance, below the runners plenum, style intake? Another reason to go dry if your platform supports doing so.
Robert

[hammered54]

The rpm window switch (along with anything else you may want to add) is usually bought afterwards outside the kit. The kits usually come with a micro throttle switch.

I think you'll find that there are more myths floating around about nitrous than true facts.


true dat!

[Trinten]

Thanks for the clarification everyone.
Right now I have a four speed manual and I usually hit 4th gear for only a few seconds before the end of the 1/4.

So I figure I'll need to spray during either 3rd and 4th, or 2nd and 3rd. With the ratios on my current transmission, spraying in first would be pretty useless. This is why I am trying to figure out the best, safest, way to spray for over two gears.

So Robert, do you agree that a direct port system would be the best way to go? Looking on nitrousoutlet, I see they have a direct port "dry" systems **section** (but no produts) - is that what you feel is the safest route?

Any recommendations on RPM window switch kits? Or are they all pretty much the same and just a matter of finding the best price?

[hammered54]

ya want'a talk fieros pm flames4me.. seems to me thats his ride also, he is/was a mod here but havent heard much of him as of late.. some nonsence about school or something like that.

or search the fourms here, there has been many posts relating to his set up....what I got was that the transmissons were/are a POS without the krypton gears.
Matt.

[Trinten]

Hey Hammered, I appreciate the tip!

With the 4 speed transmissions, none of the available gear ratios were all that great, but some better than others. The biggest issue I have seen with them mated up to big power engines is that the case itself will actually split apart, and *then* the gears destroy themselves as the case comes apart (since everything falls apart inside).

Eventually I'll be swapping it up to the Pontiac G6 manual transmission with some changes. Worst case I'll drop in one of the "heavy duty" automatics that can be made to work with the Fiero... to my knowledge, no one has managed to blow one of those apart (yet).

[Robert56]

Thanks for the clarification everyone.
Right now I have a four speed manual and I usually hit 4th gear for only a few seconds before the end of the 1/4.

So I figure I'll need to spray during either 3rd and 4th, or 2nd and 3rd. With the ratios on my current transmission, spraying in first would be pretty useless. This is why I am trying to figure out the best, safest, way to spray for over two gears.

So Robert, do you agree that a direct port system would be the best way to go? Looking on nitrousoutlet, I see they have a direct port "dry" systems **section** (but no produts) - is that what you feel is the safest route?

Any recommendations on RPM window switch kits? Or are they all pretty much the same and just a matter of finding the best price?
Nitrous Outlet is fine for wet needs, but they really don't support the dry technology at all. the company that really supports and has developed the first true dry kits that use the PCM via piggy back controllers is Harris Speed works and they are the ones that plumbed my intake for DP dry and I run their controller (for the LSx only at this time). You could could plumb it your self also with a little research. I think the DP Dry can be the safest route for a street/strip car yes, too pricey for most though. I have a DP Dry pictorial on my site. At this time, I really don't offer plumbing services outside local work.
Robert
Robert

[Trinten]

Sounds like I'll have to get in touch with them! The Coil Near Plug system uses the 411 PCM (same used by LS engines), so it should work with their system.

I'll put them on my contact list once the EFI stuff is done. Thanks Richard!

[Robert56]

If you do figure out it will work, let us know.
Robert

[mrr23]

welcome to the site. i used to run the holley stealthram years ago on my 86TA. i used to own www.stealthram.com (http://www.stealthram.com) as well. working on getting it back up. i used a single nozzle setup at a 150 level mainly with a few runs at 200. a nice activation controller would be the trick performance parts dual stage controller that i used to have on my 2000 formula. there's a thread on here about it as well.

[Trinten]

Hey Mrr!

I actually scoped out your forums for a while when I was looking into the stealthrams complete stand alone system (that came with the commander 950) - even touched base with a guy who had posted there selling his (for a great price, too) but I couldn't find any shops locally that wanted to tune it!

So I just put it off and figured I'd find other options, but the intake part of it is still highly recommended, so I'm sticking with that. :)

[Trinten]

Hey Guys, figured I'd resurrect my original thread instead of starting up a new one.
The engine is the same, still a manual transmission (though now a 5 speed with a LSD).

In the process of ditching the carb and switching over to EFI right now. The guy doing the work is setting it up with a MAP-sensor style (aka speed density), using the 7730 ECU. I wanted to go with a F.I.R.S.T. intake, but got a great deal on a Holley Stealth Ram (including a lot of odds and ends for it, and an angle milled throttle body spacer with two fogger nozzles).

When the discussion of nitrous came up, the guy doing the EFI conversion strongly suggested I go with a wet kit, it would reduce the complications of programming the ECU, especially since I want to use a progressive nitrous controller (another thread here, lol) to ramp up the nitrous, instead of a single hit. I know that wet is not what has been recommended so far, but I'm not in a knowledgeable enough position to debate it with him.

So, here's the new, amateur questions. Do I just pitch/sell those fogger nozzles, and get a wet kit designed to work with a throttle body spacer? Or should I pitch that too and get a Direct-to-port system and have the HSR modified to accept that?

[Curtis_conway]

Go with the wet kit at the throttle body.This will be the easyest and safest way. Is there a reason you want to do a progressive deal? A 150 shot isn't to crazy, if your talking 250 plus then ya go with a progressive and buy a couple extra noids. you'll need em

[Trinten]

Hi Curtis, thanks for the feedback.

Part of the reason for the progressive is to reduce the torque-shock loading on the transmission.

The transmission I'm running has held up well in other fairly high horsepower apps, a guy running a turbocharged engine putting down 500/500 actually tried to break it when he got tired of it, just to see how much punishment it would take (decided to go to an automatic)... however, as the saying goes "your results may vary".

So it's more of a safety net.

Complete side note - did Robert close up his nitrous shop all together? Or did he just get a new website or something?

Edit: removed the link to the product I was asking about... even though it came up under "Wet kits", it still said that additional fuel was provided via OEM fuel supply...