Experiment.Seven

So i have ~135,000 miles on my stockport 12A.

I want to turbo-charge it and cram 5PSI into it. I know it's possible but for how long do you guys ESTIMATE it will last before i pop a seal?

I would be using a S4 manifold
T4 Hybrid Turbo from RS
My nikki re-jetted by RS
2.25 inch piping back to some type of 3" cat back

Experiment.Seven

Also i'm not sure if this SPECIFIC question has been addressed but:

For 5 PSI how much more fuel do i need to flow? Should i get a rising rate FPR coupled with a 5lb fuel pump? Or higher flowing pump than that?

The T4 Hybrid loses effiency at about ~6K RPM? Or does it go all the way to 7?

PercentSevenC

Am I correct in assuming this is a blow-through setup?

You must have a rising-rate FPR, such as the Aeromotive 13301 (what I'm getting). You need a far higher PRESSURE fuel pump than 5 PSI. If your boost is 5 PSI and a Nikki normally likes around 3 PSI, and figuring a 5 PSI fuel system loss and assuming you use a quality return-style pressure reg, you'll need a fuel pump that can provide an absolute minimum of 13 PSI, plus a safety margin of several PSI. Flow just needs to be adequate for your projected power level. Most people just use EFI pumps. I'm using a GSL-SE pump, but that might or might not be adequate for you, again, depending on your planned power level. Are you using a surge tank, or are you just going to stay off boost when cornering when the fuel level is low?

Also, any particular reason why you're using a 2.25" downpipe? Stock TII is 2.5", and if you're using 3" anyway, why not go 3" all the way back? And I don't pretend to be a turbo expert, but 5 PSI seems like awfully low boost for a hybrid turbo. No way it's going to run out of breath. In fact, I would think it would be way out of its efficiency range at only 5 PSI on a stockport 12A.

FirebirdSlayer666

iTrader: (3)

Yeah if you plan to only run 5-8psi(stock boost for a Turbo II), I would just use a stock S4 turbo since you'll be using the S4 manifold. Just port the wastegate so you don't get any creep. 2 1/2" exhaust would be adequite for low boost like that. It's hard to say how long it would last. It could last another 50k miles or it could pop the day everything is done. There's just too many variables to consider

Experiment.Seven

Thanks alot for the input and info. Helps me out alot guys.

Alright so here is the list then:

Rising rate FPR
EFI FP (15+lbs will do?)
S4 turbo and mani (twin scroll mod)
2.25 inch back to Catback
Ported wastegate
Ebay BOV
Hard piping
Ebay IC
Ebay (gromets? Couplers?)
Carb hat from RS



Anything else?

Experiment.Seven

Oh and yes this will be a blow-through. =]

FirebirdSlayer666

iTrader: (3)

To be perfectly honest, I think it's almost a waste to run an intercooler with such little boost. In my opinion, it probably isn't going to do much for you. Yeah it will cool the charged air but, depending on the size of the IC and the size/length of the pipes, you'll more than likely see a pressure drop especially from low boost. Of course I may be way off base here but that's my understanding anyway

Experiment.Seven

Yeah actually i see exactly what you're saying.

Hmmm..maybe at 10PSI the IC would come in handy but yeah...5PSI is such a small amount of pressure. Say i got a very small IC..lol. FMIC but it will be small. =]


How much of a gain in HP will 5PSI net me? 20, 40, 60, 10000? lol
- 10PSI adds?

Experiment.Seven

Something like this for a IC perhaps?

http://cgi.ebay.com/ebaymotors/CXRac...spagenameZWDVW

EDIT: nevermind the link doesn't work. =/

82transam

iTrader: (18)

That I/C should be plenty for that boost, and like he said you might not even need a i/c at 5psi... The 12at that was available in these cars overseas had no i/c on them and ran similar boost levels...
As for expected power gains I'm really not sure, but it will definatly be worth it as long as you keep the costs down

Experiment.Seven

Hmm, well a well-placed CAI should suffice. =]

Keep cost down. :P

PercentSevenC

I'm not going to use an IC. Not worth the time and cost. And I still say you should just use a stock TII downpipe. They fit pretty well and won't restrict you like 2.25" might well. Plus, you can use Racing Beat's thickwall 2.5" piping.

Experiment.Seven

Great idea Percent. I'll see costs and determine which one is better.

Do you have a build thread yet?

Rogue_Wulff

How long will it last? Anywhere from 30 seconds, to 30 years.
Personally, i would never even consider adding boost to an engine that already has over 100K on it, without doing a full rebuild.

Experiment.Seven

Hence the OP. lol

I need to see from previous experience/situations. Anyone ever just slapped a turbo on a engine with 100K+ miles?

PercentSevenC

No build thread yet, because I haven't actually started the build. I'm still collecting components. I'm hoping to put everything together this summer.

FirebirdSlayer666

iTrader: (3)

If you want to run a cheap intercooler for a little bit more boost, I'd modify a Turbo II top mount and run it up front.

Experiment.Seven

Has this ever been done?

PercentSevenC

I think Hyper4mance2K did that on his old setup. I considered it as well.

Experiment.Seven

Hmmm seems like a good idea actually. Is it very efficient?

85rotarypower

If you absolutely want to run an IC, just use a modded TII top mount. Its good to probably 10psi of boost, after which it isn't very effective as an IC. But at only 5 psi, its not needed. These engines run a fairly low compression ratio by comparison to some cars now. I've seen 5psi run pretty well without an intercooler and higher compression ratios and not blow up. Its all in the tuning in the end.

As for a turbo, stock S4 is more than enough. You could probably get away with even a T3 with that low of boost on a 12a. I agree with the statements about the downpipe as well. Use a stock TII downpipe to a 2.5" all the way back, more than enough again. I would think that 30-40hp is not out of the question for a gain, but I wouldn't expect any more than 45hp.

Check out http://www.aaroncake.net/RX-7/mods.htm . It pertains to 2nd gens, but many of the concepts apply here as well. Mostly just ignore the fuel injection parts.

Experiment.Seven

You suspect about a ~40hp gain from 5PSI? =]

How about form 10PSI? I know they are just estimates but it gives me anidea at exactly what i want to do.

Scott1982

Oh no the power bug that infects us all has no mercy and will only go away when our cash is gone

Experiment.Seven

Hahah i've yet to be infected by this synical thing but it should be intense once i do.

I drove an EVO VIII with 400 AWHP and damm..i mean DAMM. =]

Made me want more power in the 7 badly.

85rotarypower

I must say that 40hp might be on the high side too, but its hard to say. The turbo 12a from japan made about 160, the NA version about 110hp there. Correct me if I'm wrong, but stock boost on that engine was around 6-7psi I think.