upgrading 930 need advice!

[930zx]

hey guys, new here and want to say Hi. I have been putting this off for months and finally getting around to doing this. I have a 1987 porsche 911 turbo that I will be upgrading. Heres a list of everything im doing for track/street car:

efi conversion with wideband o2
full bay intercooler
carrera intake manifold & heads
twin plugging
msd ignition
3.4 cylinder & piston upgrade
carrillo rods and arp rod bolts
tial wastegate and blow off valve
1.1 bar of boost
gt evo II cams
methanol injection system
regeared 4 speed transmission
schnell headers
fabspeed dual exhaust
garret gt turbo
114 leaded octane when at track

is there anything else I can do? I was told that the carrera intake manifold can allow flow up to 630 horsepower. I want more than that. When I have the engine torn down what else is there to do? thanks

[930zx]

btw my goal is 700+ rwhp

[bkreigsr]

if the car is going see much track time, you're going to be wanting another gear or two when it comes to keeping the turbo in the sweet zone if you stick to the 4 speed.

[Garen]

What about suspension? If you are going to track the car and want to run coil-overs, make sure you beef-up the shock mounts, and also make sure you upgrade the rear anti-roll bar mounts to WEVO units. You WILL break the stock ones... Also, research on this board and rennlist will yield you better solutions as to what headers/exhaust, and manifolds to run. The schnell, B&B and GHL headers probably won't be able to support the HP levels you are seeking. Bob Holcomb or Marco Manzie headers will be better suited I think.

When you upgrade to a decent stand-alone EFI computer like the Link, MoTeC, etc, you have the option of individual cylinder ignition coils, so the MSD may be unneccessary.

Do a search on this and rennlist, and check out project cars by Eric Hood (stroker racing??), Don E, Schokm, anything by Imagine Auto, etc.

Methanol as fuel, or just as an added spray like water injection?

And yes, the 4 speed may be a bit off-gear compared to newer 5 & 6 speeds, but with 700HP, you can probably manage better.

Anyway, hopefully the experts will chime in with their thoughts, and good luck.

Garen, 87 930

[930zx]

thanks, I have heard of bob holcomb, does he have a site? thanks

[930zx]

also whats the ideal transmission to run? a g-50 tranny?

[David]

Welcome to board.

Your project sounds a bit like mine.

Are you doing the work yourself?

In case you haven't been there, there's a pretty good turbo group on Rennlist.

[Craig 930 RS]

1.1 bar at the track.......
No. Not even with EFI.

[dailydriven911]

why is 1.1 bar of boost too much? I'm assuming your not building the motor and this is why. Many cars run more boost than 1 bar, my old srt-4 ran over 1 bar stock. Just upgrading the fuel system/safc and turbo/exhaust/ic and you can push 2 bar on a stock engine. I know there are alot of factors that come into play please explain I'm somewhat new to the porsche engine/engine management

[Craig 930 RS]

"Not building the motor"? I don't build motors.

Clearly you don't know about 930 turbos. Hell buy a 930, slap a 1.1 bar spring on it and let us know how it works out for ya.

Look around on the Rennlist 930 forum and you'll see why even with EFI, 1.1 bar on a *tracked* 930 engine is absolutely NOT a good idea.
You'll get phenomenal amounts of HP with .9 bar.

[beepbeep]

Originally posted by Craig911
1.1 bar at the track.......
No. Not even with EFI.

Why not? We run 1.2 and 1.4 bar at track w/o problems on a 3.6TT engine. It does have flameringed heads but we never had problems with blow-by.

[beepbeep]

Originally posted by 930zx
hey guys, new here and want to say Hi. I have been putting this off for months and finally getting around to doing this. I have a 1987 porsche 911 turbo that I will be upgrading. Heres a list of everything im doing for track/street car:

efi conversion with wideband o2
full bay intercooler
carrera intake manifold & heads
twin plugging
msd ignition
3.4 cylinder & piston upgrade
carrillo rods and arp rod bolts
tial wastegate and blow off valve
1.1 bar of boost
gt evo II cams
methanol injection system
regeared 4 speed transmission
schnell headers
fabspeed dual exhaust
garret gt turbo
114 leaded octane when at track

is there anything else I can do? I was told that the carrera intake manifold can allow flow up to 630 horsepower. I want more than that. When I have the engine torn down what else is there to do? thanks

It's a sound build sheet but I would remove methanol injection. All auxillary injection system are regarded as a band-aid and shouldn't be used at track...merely at a drag strip. If you map your engine to actually take advantage of methanol injection, it will knock itself to death when methanol tank runs dry on a track. If you map it so it survives in case of unfortunate event of dry tank, you won't have any use of it.

So methanol has to go.

Also being a single turbo system, you'll need pretty big turbo to achieve 700hp. Turbo that big will be somewhat lazy.

I recomend binning 700hp and methanol plans. If 700hp is important then warmed over 3.3 isn't good choice to begin with. I would sell it and do a TT-conversion of 3.6 plant. 700hp on 3.3 engine is achievable but not cost-effective.

If you really want to keep 3.3 I recomend using following build sheet:

- 3.2 heads (3.3 has small ports, won't scale well with HP)
- keep the cylinders stock (increase to 3.4 won't give you much and costs a lot).
- JE pistons (instead of buying 3.4 P&C's)
- Garett GT35BB turbocharger.
- Custom made headers.
- Keep the OEM wastegate, it's better than Tial.
- BOV won't give you more power so you can use any BOV you want.

That would give you relativly fuss-free 600hp in track tune.

More than that and it will become unreliable money-pit.

If you need more than that, I recomend selling 3.3 engine alltoghether, finding N/A 3.6 engine and doing a TT conversion with twin GT30BB's. It already has twin plugs, heads with big ports etc. It's much cheaper to extract that kind of power from such engine (relativly, nothing is cheap when you talk 700hp).



So to round it off:

1. 3.3 engine is quite a bad design to go hunting big hp numbbers. It has small intake/exhaust ports, bad cams, single plug heads etc. Redoing everything to suit big numbers costs a lot.

2. Methanol/water/whatever injection sounds cool when read in import drag-race magazines but is nothing to be used on track, for reasons mentioned above.

3. Spending $$$ on 3.4 conversion on 3.3 car is waste of money. 0.1L increase can be eaten up by raising boost 0.05 bar of boost or so.

4. If big horsepower is important, 3.6 engines are much much better material to work with as most of "problems" (displacement, twin plugs, big ports) are already ironed out.

5. More than 1 bar on track would mandate flame-ringed heads and better head studs, but is possible.

In my book, 500hp is break-even point where fiddling with 3.3/3.2 engines isn't worth it unless you have access to lot's of parts and good engineering facilities.

About gearbox: 930 gearbox will certainly stand the torque. It's gearing vs. track work will depend on amount of turbo lag which itself will depend on which engine design you opted for.

With other words, it's entirely possible to see scenario where you actually achieved 700hp from a 3.3 with huge turbo (after throwing heaps on money into it) just to see the car being overtaken on track by a bloke with less HP but smaller (and thus more responsive) turbochargers.


So you either keep your 3.3 and just do as good buildup as possible w/o hunting bragging rights HP-figures or go 3.6 route.


Cheers!

[VZ935]

Ran 1.1 to 1.2 bar of boost on my twin turbo motor .. never DNF'd .. track records, PCA wins... kicked just about everyones butt... 1.1 bar is nothing.

I have done all of this before...and I was successfull . If you want my take I am happy to share my info with you . Just PM me.

[David]

I don't see a problem with 1.1 boost running 114 race gas. On pump gas no, but with race fuel I don't see a problem.

You should have different fuel and ignition maps for pump and race gas.

I would do the flame rings on head/cylinder surface. I didn't and I'm worried I'll regret it.

If you haven't already, you'll also probably want to install larger piston squirters.

[930Jim]

You should consider additional cooling with a front mount oil cooler.

I'm in the middle of a build myself with:
-964 cams
-Autronic SM4 fuel and (twin) spark
-3.4 Mahle P&C's
-Extrude Hone'd heads, inlet and exhaust turbo housings, inlet pipe and intake manifold.
-ARP studs
-B&B front mount oil cooler and I/C
-5 way grind
-72# Siemens injectors
-K27HFS

[WERK I]

7.0 to 7.5 compression ratio if you're going for 1.1 to 1.2 boost levels.

[MikeY930]

the methanol is some good stuff

[beepbeep]

Originally posted by MikeY930
the methanol is some good stuff

It is , if you are into Funny Car dragracing.

For road-going car, no. It requires special fuel piping, it will dilute your engine oil, it will require frequent rebuilds and you'll need to carry much bigger fuel tank as energy content per liter is low. I also wonder of it's permitted at all.

As I see it, methanol injection is pipe dream that is totally out of place on a track car.

It sounds good when you read about it but complexity vs. usability ratio is very high.

I would rather have usable and dependable turbocharged engine that doesn't require constant rebuilds and tweaking.


BTW, we run 1.2 bar of boost on Euro pump gas, (V-Power, 99 octane RON) and 7.5:1 C/R. No problems with detonation. Twin plugs and MBE aftermarket ECU.

[Bruce M.]

My build is quite similar. I have Motec, and a 3.6 crank to go with the 3.4 Ps&Cs. No MSD (don't need it with a box like Motec). No methanol. G50 5-speed with Wevo short shifter.

512 to the wheels at 1.0 bar. To get to 700, as somebody has said, would require a much bigger turbo in a single-turbo 3.3 app, and that would be too laggy, in my opinion.

Engine built by Bob Holcombe. To my knowledge, he doesn't have a website. Kind of an old-style guy in some ways. He uses Motecs now, though, instead of the old Zytec.

[VZ935]

Bob Holcomb has been around for a long time. Used to build Martin Snow's motors . Martin was the 'King of the Hill" back in 1992-1994 in POC and PCA club racing before he went pro...used to do 1:22's at Willow Springs.. some of us are under 1:20's there now but at the time a 1:22 was untouchable, and pretty much still is for most.. zytec motor...and Bob used to build his own throttle bodies..we actually have one of his old zytec motors on the shelf.

Some ran the 935s boost levels of about 1.7-1.8 for sprint races 1.2-1.4 for endurance races... unreal! I know I will never turn mine up more than 1.4 . At 1.2 and 7500 my engine builder says the motor will last forever .. fffoooorrrreeevvvverrrr.. I plan on holding him to that !