930 mods

[aus930]

hi guys.
Hoping you guys can shed some light on a few questions from a newbie.

New to the 930, in fact my car is on its way from japan as we speak,until now im a gtr skyline driver and had a few, the last being in excess of 800hp.

Mods are the first thing on the shopping list, car has aftermarket exhaust only i beleive.

Im a little confused on a few issues.
It seems 450hp is max with factory fuel injection with larger turbo, cooler, 1 bar etc.
Is this true?

I hear a lot of talk about enrichment, so im assuming the factory fuel inj isnt capable of supplying enough fuel beyond 450hp.

What is enrichment and how does it work?

Also most of the research ive done indicates k26 and k27 are a touch on the laggy side, having used garret turbos on my gtrs, this is my preferance as a replacement and having a mate who builds them helps, although outright power is important, driveability is more important to me.
i would rather sacrifice some hp for less lag.
Can anyone supply specs of a garret that would still get me over 400hp and provide less lag.

In an ideal world i would like standard fuel system,standard cams with new turbo,exhaust,intercooler and still achieve 400hp+.
Is this achieviable?

I have a stock 86 carrera and my biggest issue is a grose shift mechanism, im used to jap cars with effortless shifts, will a short shift in the 930 help or is that still pretty harsh to shift.

Thanks for taking the time to listen to my ramblings and any help would be much appreciated.

P.s. if anyone could provide any links of websites that can assist a new guy , it would be appreciated

[Langers]

aus930,

K27s seem to be just about fine for most people on this board. You have to realise that 30 year old fuel injection technology and a single turbo IS going to have more lag and be less drivable than a modern EFI twin-turbo engine.

I *think* '86 Carreras were still running 915s, if so, you should notice a substantial difference between the Carrera and the 930. (If the '86 is running a G50 then the difference won't be as big.) 930s aren't exactly smooth as butter to shift, but they more than make up for this with their robustness.

My understanding of fuel-enrichment is that it's a poor man's way of ensuring the engine doesn't lean-out under boost; it usually involves adding a 7th injector and perhaps upgrading the fuel pump just to be safe.

If you have a mate that builds the turbos he should be able to work out the correct specs and compromise between top-end power and drivability.

Changing the cams on 930s is usually a very good idea, it helps to change the off-boost characteristics of the engine and give you less turbo lag. Do a search, there should be some info on the BBS. Edit: well I was close...the cams don't help lag but will give you a bit more torque.

Hope this is somewhat helpful.

P.S. Not trying to be rude but perhaps if you improved your grammar, punctuation and sentence structure you would get a few more replies. It's hard to read your post.

[aus930]

thanks and as you can see grammar is not one of more strong suits,hope its more legible now.

Understand this is not a modern jap car, but was hoping someone had already done some experimentation with a garret , so we dont have to do it.

the 930 is a 1987 4 speed are the shifting characteristics likely to be similar to the 86 carrera or better

[beepbeep]

Originally posted by aus930
hi guys.
Hoping you guys can shed some light on a few questions from a newbie.

New to the 930, in fact my car is on its way from japan as we speak,until now im a gtr skyline driver and had a few, the last being in excess of 800hp.

Cool!

Mods are the first thing on the shopping list, car has aftermarket exhaust only i beleive.

Im a little confused on a few issues.
It seems 450hp is max with factory fuel injection with larger turbo, cooler, 1 bar etc.
Is this true?

Yes. You can enlarge fuel-head and do some other tricks on CIS but it's basically dead-end.

I hear a lot of talk about enrichment, so im assuming the factory fuel inj isnt capable of supplying enough fuel beyond 450hp.

Well it's not just matter of supplying enough fuel, CIS can be made to flow lot's of fuel but it still has it's barn-door air flow flapper in the air stream which limits max flow on the end no matter how.

What is enrichment and how does it work?

Basically an extra injector triggered by pressure-switch. It's a band-aid.

Also most of the research ive done indicates k26 and k27 are a touch on the laggy side, having used garret turbos on my gtrs, this is my preferance as a replacement and having a mate who builds them helps, although outright power is important, driveability is more important to me.
i would rather sacrifice some hp for less lag.
Can anyone supply specs of a garret that would still get me over 400hp and provide less lag.

Yupp. Garret GT37BB will do the trick. GT40BB with smallest exhaust housing is worth considering too, in case you want 500hp+ .

In an ideal world i would like standard fuel system,standard cams with new turbo,exhaust,intercooler and still achieve 400hp+.
Is this achieviable?

No. Not with standard cams. They are very mild and generally first thing to go. CIS might be able to support 400hp with some fiddling but it's on the edge.

I have a stock 86 carrera and my biggest issue is a grose shift mechanism, im used to jap cars with effortless shifts, will a short shift in the 930 help or is that still pretty harsh to shift.

Yes, short-shift will help shifting somewhat but 930 tranny will always have balky shift-feeling due to it's physical size. It's equiped with some kind of synchromesh as 915, so you can see it as overgrown 915. If you want nice and slick shifting, think about G50-conversion. It uses Borg-Warner synchromesh and is much "slicker" to shift. Of course, that means you'll need to convert to coilovers in the back too...

Thanks for taking the time to listen to my ramblings and any help would be much appreciated.

P.s. if anyone could provide any links of websites that can assist a new guy , it would be appreciated

Just do a search on "HP junkies" on this forum...

[aus930]

thanks beepbeep.
any idea of wheel sizes for gt37bb.
also what cams,i hear a lot of talk about sc cams,is that just a non turbo cam,if so from what model

thanks

[beepbeep]

Stock GT37 comes in only one size as far as exhaust housing go. Compressors can be had in three different sizes,
- 76mm impeller, 52 trim, 0.54 A/R
- 82mm impeller, 52 trim, 0.54 A/R
- TO4 housing 76mm, 52 trim, 0.70 A/R

- 82mm impeller, 52 trim, 0.54 A/R has best looking compressor-map, in my eyes.

Yes, SC-cam is basically cam from 911 SC...it has more lift and slightly longer duration w/o being too aggressive. If you really want power, go for group B-cams. Otherwise SC-cams are good first step.

[aus930]

thanks mate

[aus930]

my skyline made 650hp at the wheels using absolutely brand name parts from japan.

im not chasing this sort of power from the 930,450hp will be enough .

thanks for your help.

[beepbeep]

I can give you a recepy for 600hp 930 but it isn't cheap and means that you either commit to it or leave it alone.

If you want big numbers be prepared to throw away most of engine bits. Trying to achieve that with CIS usually just ends with frustration and lot's of money spent w/o results.

Ze evil recepy:

1. 6 x Dual plugged Carrera heads.
2. Carrera intake with fuel-rails.
3. 6 x 55lb/hr injectors
4. GT40 (BB optional)
5. Big intercooler (Kokeln or similar)
6. Autronic SM2 sequential injection and direct ignition ECU
7. Free flowing exhaust with one straight-trough muffler
8. 1.1 bar of boost
9. (Optional) G50/52 gearbox and coilover rear suspension

That's about it.

You cannot expect 930 to react to mods in same way as your Skyline did. Actually, it needs lot's of induction/fuel parts changed to trully deliver good power.

Fiddling with small stuff one at the time usually ends up with doing som variant of "the recepy" anyway (as long as you are HP junkie and you sure sound like one)...

[aus930]

guys it comes down to how fast can u afford to go,my skyline had a pair of kkk26 turbos and a 6speed dog box, it was pile of s**t to drive.
I want a nice driveable porsche now and only want to explore the possibilities without cracking it open.

At this stage im thinking,gt37 or gt40, intercooler,exhaust,1 -1.1bar,sc cams.

From there hopefully not far away from 400hp.
after that i guess we will see if the bug bites.

The gtr skyline started as mild mods and $50k us later,we achieved what we wanted.

Then i pulled the engine out and selling with a stocker.
(my names dean and im a hp junkie)

[RarlyL8]

As Beep said, you can get a solid 400hp from the 930 with bolt on mods.
SC cams will help driveability but add no top end power (only torque).
Change the exhaust, turbo, and wastegate.

Reduced lag is more complicated. Lower gears, SC-like cams, proper turbo and short headers.

Although not considered an upgrade, changing the 930 4-spd out for a 915 will add 100hp to the seat of your pants. I've driven both. The G50 is more robust but also very expensive to purchase and convert.

The recipe that I have used is a combination of light weight, low gears, and mild mods. Just shy of 400hp in a 2400lb car with low gears goes a long way twards creating a very driveable beastmobile.

[aus930]

THANKS for the info guys,keep it coming,the more info i gather the more of an informed descision i can make when the time comes

[dean]

I have a 3.0L 930 motor in my car. I installed a 1 bar spring, shorty headers, K27-7200 turbo and a large intercooler. I have 328 RWHP. I don't think the lag is bad at all. The boost starts at 2500 rpm and I get full boost at 3k. I also have a G50 and that helps a little

Go to http://www.c2turbo.com/forums/index.php? and you can look at the dyno runs and see what they did to get the power they have.

[5axis]

Here is a nicely done 930 that I saw listed FS.
http://www.jamesgw.com/cars/930/930.html

Notice the small fortune in suspension parts as well.
I really like what he has done with his gearing too.
There is a balance to these cars that few other high HP cars can match.
None can match the history.

david 89 turbo cab

[aus930]

thanks blown ,that was exactly what i was looking for.
doesnt seem to be to many prepared to play with anything other than k27 though.they seem to work.
this appears to be the typical mods most take and seems good for anywhere between 350-400@the wheels
SC 330 Cams
K27-7200 Turbocharger
Kokeln Intercooler
1 Bar Boost Spring
GHL headers and muffler

[beepbeep]

Originally posted by 5axis
Here is a nicely done 930 that I saw listed FS.
http://www.jamesgw.com/cars/930/930.html

Notice the small fortune in suspension parts as well.
I really like what he has done with his gearing too.
There is a balance to these cars that few other high HP cars can match.
None can match the history.

david 89 turbo cab

That's a mother of all modded 930's! He has all the good stuff I can think of worth having in 930...G50/52 is only thing missing that i can think of.

[aus930]

i think we can put that one on most peoples wish list
http://www.jamesgw.com/cars/930/930.html

[Bruce M.]

Well, no offense, but a Protomotive-modded Motronic is not really top o' the line...

For that you'd want a fully programmable fuel injection/direct fire black box, which range from Electromotive, to Haltech, to DTA, etc., on up to Motec.

[aus930]

Does anyone have any close up shots of an after market efi fitted to a 3.3,maybe before and after.

[dean]

Damn, Ask me in a couple months. I will be doing the EFI thing this winter