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another crossroad...do i port or leave alone?

ok so im in way too deep anyway and im thinking that while my heads/barrels are being flame ringed should i heave them ported?

but its not that easy...if i were to port could i/should i then run a gt2evo cam rather than my 964's?

and while im there do i use a different turbo to the k27hf2 that i was planning on using?

this is the build so far...

3.3 case with arp bolts, shot peened balanced coated rods and supertec studs, coated je's , 8-1 comp (negotiable), flame rings, rebuilt twin plugged carrera heads, 3.2 intake, 964 cams (at the moment), k27hf2 (i think) 1 bar(ish) and sds efi.

i won't be doing much track stuff, maybe a couple of track days a year. this car is going to be something to play in every now and again when i get some free time from either working or being a dad (when the will that be then?!) so im not too bothered about a bit more lag if i choose to go with evos and a bigger turbo. the problem is that i don't know which direction to take but i do know that porting the heads and fitting different cams and adjusting compression is easier done now rather than when its built.

so what are peoples views?
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Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-11-2005, 11:54 PM
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come on hp junkies-i know you are out there........!
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Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-12-2005, 06:15 AM
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Andy, The carrera heads are plenty for your application. If you intercool properly, use the appropriate fuel and proper turbo selection you can play around with your boost. Sounds like 400+ ponies are uh comin!
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Old 11-12-2005, 06:36 AM
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Andy, did you use turbo valves in your 3.2 heads? I'm just starting to slide down your slope
Old 11-12-2005, 08:21 AM
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When I prepared the heads for my Carrera intake I just opened the intakes to fit the manifold and blended a few areas on the intake and exhaust. In hindsight, I should have had them flow tested and ported since the budget is out of control anyway.

When I bought the HF2 from IA, Stephen asked if I upgraded the rods. Apparently there's some concern when you get over 500 rwhp which you would have with the HF2. BTW, I used Pauter rods.
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Old 11-12-2005, 08:38 AM
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wise words aaron! mike, the heads were refurbed when i bought them with new guides and stainless valves. see pic.



Dave, interesting point with the rods, im using standard shot peened rods-hmmm, ill have a chat with steven
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Andy

1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-12-2005, 08:58 AM
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Thanks Andy, so is that the way to go? SS over the sodium filled ones? I've got the heads, I just have to collect some parts to rebuild them.
Old 11-12-2005, 09:03 AM
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Ive seen a few people using ss valves in turbo motors-don't know if the sodiums are a better bet or not-maybe someone else can chime in on that point?
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1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-12-2005, 09:34 AM
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I had my heads port matched and flowed. So far, with one dyno behind me, I have not seen a difference (increase) in HP numbers.

Also, I went with the stock valves because of cost, my application is mostly street and my machine shop (JB Racing) said there is no advantage for what I wanted to do.

These issues might be important if you are worrying about .10ths of a second. And that's IF you can tune the engine correctly to get the most out of the setup. At this point, my recommendation would be to spend the money on a competent tuner (big bucks - tuner+dyno) that knows what they are doing over parts that most likely will not result in any appreciable gain.
Old 11-12-2005, 05:28 PM
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I should have said my heads were matched to a 3.2L head profile.
Old 11-12-2005, 05:29 PM
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sodium filled exhuast valves are safer. Andy, yours are flat bottomed, it is possible they are actually sodium filled.

I have seen many turbo cars use reg. stainless exhaust valves and be OK. many of these were 4v/cyl though and I think 2 lighter smaller valves are at less risk of overheating.

Cheers,
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Old 11-12-2005, 06:13 PM
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Don, I'm curious about your comments about tuning. After I took the EFI101 class, I thought the dyno tuning would be pretty straight forward. I.E. set the AFR and then set the timing.
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Old 11-12-2005, 06:52 PM
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David, if you get a chance, definitely take the advanced efi class. It really helps to further demistify the process. I have helped out at the local dyno where I took my efi101 classes a couple times a month. Many times the difficult part of tuning is that the vehicle still has some mechanical issues, wiring, sensor problems, boost controllers not functioning etc. AFR and timing are straight forward, but cold/hot start settings and throttle transitions can take some time. The ecu/system your working with can also throw you curves(as DonE is well aware of ).
Old 11-12-2005, 09:58 PM
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thanks for peoples inputs. the more i think about it the more i m thinking that i should just stick with un ported heads and 964 cams as it will make for a slightly more tractable street car. plus, at every crossroad so far i have just gone large at the risk on missing out on hp gains. im thinking that with my mods so far and maybe the hf2 I should see somewhere near 500 rwhp (please correct me if im wrong) so maybe i should leave it at that and concentrate on other parts of the car
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1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-12-2005, 10:47 PM
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Andy there is hp to be gained with porting no doubt, but for the hp you are looking to make you might as well just run an extra pound or two of boost if it does not do what you want. Just for the record I have a friend who just dyno'd a 930 that he built. It is a single turbo 3.5 that made 620rwhp at 17 pounds of boost on a conservative dyno. First time at the track with only 3 passses the car ran 140mph on low boost and real close to the 10's with street tires! With more boost and a more experienced driver who knows what it will run. Just proof you dont have to throw down huge hp numbers to fly.

Eric Hood
Old 11-14-2005, 07:23 PM
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hi eric, do you have an ingrediants list foe that engine?
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1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-14-2005, 11:54 PM
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Quote:
Originally posted by 125shifter
Don, I'm curious about your comments about tuning. After I took the EFI101 class, I thought the dyno tuning would be pretty straight forward. I.E. set the AFR and then set the timing.
Correctly tuning your custom car is not straight forward, if you want to maximize the mods you have installed. I'm going to give you an opinion based on my last 4 months of tuning my TEC3r, so beware - one car, one system, novice tuner.

Tuning WOT is not so difficult. I could give you a map right now that would be close (depending on the mods of course). Fine tuning is not so straight forward. For example, the big lazy turbo I have needs lots of timing at a specific RPM to get it to come up on boost at a reasonable time during acceleration. Too much timing, and the engine is damaged - too little, and you leave all those mods on the table because they contribute nothing at improper timing.

[After proofing this, I need to further say that timing is everything (no pun intended). Cam timing and ignition timing are paramount to a good running turbo car. Get these right, and the rest builds from these.]

Tuning for drivability (I tune my car for drivability and torque) is completely different. I want a car that will cruise at 2700 rpm, pull the correct AFR's (14.0 or so), having proper timing (ready for accel and capable of cruise) and add enrichment when I press the throttle - but not too much to bog the motor. See where I am going on this?

Then add temperature variations. When I tune in the morning, my VE values are different in mid afternoon. There are lots of correction tables available for this, so you have to choose a representative time of the day to use as your base line.

Now idle. My car likes to idle with low timing and fat AFR's. Unfortunately, I have big injectors (72lb) and they are near their effective min inj times - the point at which they stop spraying and start to dribble (bad for smooth idle) - for my idle.

Now that you think you are on to something, go through the gears and watch your AFR's. You will probably notice different AFR's for each gear, but similar vaccum and rpm's. Why? Because of the throttle position and relative load on the engine. You can tune this too, but it is not straight forward - it takes time and something I did not count on - Patience (lots of patience).

I now use the O2 sensor in a limited closed loop circuit. In other words, I use the O2 to manage the AFR's above 1500 rpm and below 100 kPa. Above 100 kPa, I have the VE tuned exactly where I want it to provide fuel - no need for an O2 here and its insurance against failure.

I am still struggling with acceleration tables - I can use manifold pressure, throttle position, or both. When the turbo is loaded in high gear, I do not want all that enrichment at once. However, when I am in a low gear and the RPM's fly by, I want enrichment to come in quick.

Someone made a comment about sensors. If your sensors are not perfect or at least calibrated well, you will chase your tail and it will never be right.

I took my car to two well known tuners. I spent over $2000 for this and I have effectively changed everything because I do not drive the car at WOT all the time. Did I piss that money away? Kinda, but I also learned a lot from them in order to get to where I am now. The car now runs very well, except for a couple of hic ups here and there. It is very drivable and has very good power. In the morning, I turn the key and it starts, THEN idles (this is a big deal, trust me).

Some of you know I have had a HUGE problem with the TEC3. Since then, they have fixed the unit and it seems to work fine now. I am most likely going to stay with the TEC3 for now, mostly because I know the software and how it interacts with the performance of the motor.

One last point. Do not look to the EFI conversion to be perfect. There are comprimises. For example, I tune for drivability and torque. If I tuned for max HP, drivability would suffer. If I tuned for economy, it would be a different car. So I picked two reasonable objectives. Someone looking to add a couple of mods to their 930, tune their new EFI car for the street and get 500rwhp will most likely be disappointed.

Sorry for the long-winded reply. I could have said, my car likes timing and likes to run fat, and been done....
Old 11-15-2005, 08:25 AM
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very interesting Don, what was your experience with efi before this project? what made you choose tec3? I can see that drivability is key in a street car. were your actual hp figures similar to your expected hp figures?
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1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-15-2005, 09:54 AM
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Quote:
Originally posted by adomakin
very interesting Don, what was your experience with efi before this project? what made you choose tec3? I can see that drivability is key in a street car. were your actual hp figures similar to your expected hp figures?
No EFI experience prior to the project.

I chose the TEC3 because I liked R Clewett and his reputation regarding service. He sold me on the unit's user-freindly interface and his follow up after the unit was sold, installed and running. Cost was also a big issue, as I bought the XDi first, not thinking I would go to EFI AND rebuild the engine. In addition, Motec was too expensive, Autronic had no US support, and there were too many opinions on the remaining kazillion other units to come up with a reasonable choice.

With all the mods I have, I was expecting 600 fwhp. At 490 - 505 rwhp (depending on the dyno), I think I achieved close to that (approx 588 using 15% loss in tranny).

I am thinking about something Stephen told me the other day - for the performance, I should have gone twin turbo for drivability and torque. I still might check that out.
Old 11-15-2005, 12:01 PM
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don, what boost are you running? whats the t61 like in comparison to a k27hf2? also, are you running a scavenge pump or gravity?
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1980 SC soon to be big hp 3.3t powered 73RSR Replica (well, I'm keeping the engine but everything else is going )
Old 11-15-2005, 12:20 PM
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