Tell me if I'm crazy with this proposed build spec

[boosted79]

I've always kind of marched to my own drum so tell me if I've gone off the deep end. This would be for the street:

79 930 80k miles

3.4L with Nickies and 8:1 CR JE pistons.
3.2 heads
Twin plugged, XDi crank fire
Custom fabbed intake manifold similar to the Jarvis with 40.9mm ID runners to increase low rpm velocity and torque
Custom injector blocks.
Custom fabbed IC with 650 ci core volume
Garrett, probably GT35r but need to study the maps, smallish hot housing for low rpm spool
here's the kicker - CIS with either BL WUR or frankencis WUR and the Edelweiss 934 air metering cone assuming it becomes available
have to modify the '79 fuel head (euro head?)
either SC or DC15 cams
rarely8 headers
reconditioned rods with ARP
probably supertec studs
of course total rebuild from crank up, bearings, recondition rockers, etc etc.
get rid of 930 BOV assembly for later style
0.8 Bar WG
AFR monitor system

The biggest challenge I see is relocating the CIS unit with a long runner intake.
Do you think it would be a dog at low rpm because of the 41 mm 3.2 ports? I'm hoping to solve that with the long runner intake, 8.0 CR and smallish AR hot housing while still making 400+ WHP at 6k?
Maybe just get a 3.2 intake and skip the custom intake.

Any and all comments welcome

[Norm K]

You forgot to list an important item - your goals (well, that and your budget).

[911nut]

I think a 964 cam matches up a little better with big ports.
Why 8:1 CR? Add a LWFW and stay at 7:1 @1 bar and with the Garrett you should have good low speed response.

[JFairman]

I guess you really like CIS mechanical injection if you want to keep it with the large amount of $ you'll spend doing all that.

With that budget you could get a 3.2 Carrera manifold and have Chris at Turbokraft put together an EFI system for you that would work well and make a lot more power.
Or look at the different EFI systems other people on the forum have put together and tuned themselves.

Everyone here is crazy to some degree so whatever...

[dos531]

Seems like an expensive way to get 400whp

[Hams930T]

Originally Posted by dos531

Seems like an expensive way to get 400whp

+1

I would stay pancake manifold, big port and EFI. You can make high 500's with that setup. I would really encourage you to have a discussion with Chris @ TK about your goals and budget. He can recommend the most optimal setup.

I was stuck on one path until speaking with Chris. He steered me in a different direction that will yield a setup that is approximate in budget but more powerful in the end. I don't want to interject an opinion here, but I think you might have better options in how you deploy your budget. I would really talk to Chris on this.

Chris.

[wjfk32]

With all the knowledge and avenues to go with, its a no brainer to go with EFI. What I did in the early 90's for CIS for my 3.3T engine, I wouldn't go that route today. You are already spending good $$$$.

GL

[turbobrat930]

I mirror what most have said on here already. If you are spending that amount of coin, reconsider going to EFI. Trust me, you will absolutely thank yourself in the end!!!!!

[boosted79]

Thanks for all the responses. Here are a few more tidbits I should have thrown in. I already have the 3.2 heads. I don't want to do anything to the stock 930 heads or pancake manifold due to the potential an all stock car has on resale. I'd just mothball them until I decide it's time to sell- will be many years away. The P&C's have 80k so I'm assuming they will need to be replaced whatever I do. The custom fab work is free by me, I do TIG. An IC core is cheap. the rest is just cutting 6061 1/8" sheet with the plasma and welding. The reason for 8:1 CR is better off boost performance. The long runner manifold, either custom or 3.2 is req'd under either scenario IMO to get the best off boost performance possible due to the large ports and relatively low CR. The Garrett is the same under either scenario, I want a map with any turbo I buy. My fear of EFI is the tuning part, I've heard of people spending thousands on dyno tuning alone to get it dialed in. How many have actually tuned it themselves? The way I'm looking at it EFI is $4-5k plus dyno time unless I can tune myself.. Does anyone think 500 flywheel HP with my proposed build is possible? The theory is the 8.0 CR with long runner intake gives good off boost torque with the 41 mm 3.2 ports then on boost is great with the long runners and big ports. With 8.0 static CR and either SC or super SC cam the dynamic CR is not much more than stock 930. With the potential from the frankencis WUR and the Edelweiss air metering cones it may not be necessary to go to EFI to get good across the range AFR's and near EFI performance from CIS.

[wjfk32]

The word POTENTIAL will always cost you more and have less in the long run. How do I know this???
Go with what's proven now...AND BE DONE WITH.. You will smile in the long run. ))

[dos531]

Originally Posted by boosted79

Thanks for all the responses. Here are a few more tidbits I should have thrown in. I already have the 3.2 heads. I don't want to do anything to the stock 930 heads or pancake manifold due to the potential an all stock car has on resale. I'd just mothball them until I decide it's time to sell- will be many years away. The P&C's have 80k so I'm assuming they will need to be replaced whatever I do. The custom fab work is free by me, I do TIG. An IC core is cheap. the rest is just cutting 6061 1/8" sheet with the plasma and welding. The reason for 8:1 CR is better off boost performance. The long runner manifold, either custom or 3.2 is req'd under either scenario IMO to get the best off boost performance possible due to the large ports and relatively low CR. The Garrett is the same under either scenario, I want a map with any turbo I buy. My fear of EFI is the tuning part, I've heard of people spending thousands on dyno tuning alone to get it dialed in. How many have actually tuned it themselves? The way I'm looking at it EFI is $4-5k plus dyno time unless I can tune myself.. Does anyone think 500 flywheel HP with my proposed build is possible? The theory is the 8.0 CR with long runner intake gives good off boost torque with the 41 mm 3.2 ports then on boost is great with the long runners and big ports. With 8.0 static CR and either SC or super SC cam the dynamic CR is not much more than stock 930. With the potential from the frankencis WUR and the Edelweiss air metering cones it may not be necessary to go to EFI to get good across the range AFR's and near EFI performance from CIS.

If you're installing the Frankencis setup, you've already installed most of the components for EFI anyways. For CIS you'd need to relocate the distributor, mount the injectors, modify the fuel dsitributor for more flow, etc. It'll be more work to make the cis work with the 3.2 manifold than to slap some injectors in there.

[kenikh]

Ignore the haters. I'm running a Tec3R and am not running EFI. You don't gotta do nothing you no wanna.

[Tippy]

I think it's one of the smartest builds because you're using Carrera 3.2 heads.

Those hung on "930 heads are a better casting/alloy/whatever", are leaving TONS of power on the table.

I've had no problems with 1.4 of boost and over 10 years of 1 bar on 3.2 heads.

Good for you.

But yeah, EFI would be great. One time hit and you're done.

[kenikh]

Originally Posted by Tippy

I think it's one of the smartest builds because you're using Carrera 3.2 heads.

Those hung on "930 heads are a better casting/alloy/whatever", are leaving TONS of power on the table.

I've had no problems with 1.4 of boost and over 10 years of 1 bar on 3.2 heads.

Good for you.

But yeah, EFI would be great. One time hit and you're done.

So what is the difference between the two types of heads, in terms of geometry, that makes them better???

[boosted79]

Well you guys are making it difficult for me and the EFI route is very tempting. And it would make BIG power with 3.2 heads and Carrera intake. You are right, the fuel head relocation would be a challenge with either a Carrera or custom intake requiring braided ss/teflon lines but that's no big deal, I make my own. But as you all know space is at a premium to relocate the fuel head. I've going to research both options more. There was a guy on here that had a similar setup to what I'm proposing, CIS with Carrera intake. I'm going to see if I can get hold of him to discuss his setup more. The thing with using CIS with the 3.2 heads is bad mixing at low RPM due to the low velocity from the 41 mm ports, that's what I hope to solve with a long runner intake. Long runner with 8.0 CR = higher velocity and better mixing and more torque with the big ports. But if it doesn't work then I'd have to go EFI. decisions,decisions.

[Tonger]

Call Chris Carroll at Turbokraft

My build is stock pistons, cylinders and heads except for 993 exhaust valves. 964 cams, modified CIS, GT35R twin scroll turbo, Garretson IC, Turbokraft twin scroll headers with dual 1 bar wastegates and ceramic coated turbo hot side and dual Turbokraft exhaust. The result is early and progressive boost that is all in by 3200 rpm.

If I wanted less finicky tuning, I would have asked Chris for his EFI system. Instead, I wanted the old school modified CIS and we're still tuning for AFR safety. This system with EFI should do 500+ HP easily.

My main suggestion would be to seriously consider the twin scroll turbo and header design. Short tube twin scroll header = early boost. Isolating the right and left sides of the exhaust all the way through the turbo effectively widens the time between exhaust pulses making equal length tube header considerations less important. It's more about minimizing the air volume to be compressed between the exhaust port and the hot side of the turbo. Early boost beats normally aspirated performance every time... It also doesn't really cost that much - no charge upgrade on the turbo but more fab on the header and one additional wastegate. The advantage of the dual wastegate system is much more wastegate area which better limits boost creep. Finally, your P & C's are more than likely fine to use again which will save you some serious cash.

Chris was (and remains) an incredible asset designing, building, and tuning the system and I couldn't have been more pleased. He has an engineering mind with regard to knowing how different builds will perform on the dyno and is a great guy to boot.

BTW, the Edelweiss Air Metering is elegant, available, apparently very effective, but definitely not less expensive than EFI. I'm seriously considering it as well.

Good luck!

[RarlyL8]

Lots of ways to retain low RPM torque. No need to ditch the pancake manifold unless you just want to go the extra mile with personal mods. Nothing wrong with that
I'm doing a 500HP build right now and expect SC drivability with CIS. As for heads, you can easily port 930 heads to Carrera or better specs. I'll post mine when they are finished.
I'm sure there are reasons for every step in your build as the items are too specific for there not to be.

[pu911]

I've got set of early 930 heads that have been twin plugged and ported to be used with Carrera manifold, I have Carrera manifold, a new TEC3 set up. Thinking about selling it all before I do something stupid like build a high HP motor. If anyone is interested drop me a line, everything is brand new.
Phil

[kenikh]