rotorheadcase

I have been looking at the turbo/supercharger route for a while now to gain some more torque and a little more horespower. I read most of the threads arguing the pros and cons of boosting a standard engine. My motor is only 7000 ks out of a rebuild so I know I have a strong engine.

Fate has conspired to present the opprtunity to pick up a near new TPC supercharger kit that has previously been installed on a 964 C4. The current owner had a problem with a significant flat spot when launching hard from standstill but this was the only time it was present. For all other driving situations the performance was as advertised. The PO contacted TPC who seem mystified and could not understand why. This make me think it may be an install problem or another issue inherent with the car rather than the kit.

I don't usually indulge in traffic light drag races but I do find that the car needs to be revved to make fast progress from a standstill. At any rate I'm keen to give it a go. The price of 965's here in Australia would make you all shudder so that's not an option and I don't want any other car, well maybe a 996 GT3

Having done a little research it seems that other owners have had various degrees of success with the TPC kit but no one has mentioned this flat spot. I recognize that there is a lot of variables with every install but I know this kit is only 18 months old so I would have thought it would be pretty well sorted.

My other question is whether the intercooler package requires a fixed tail or if it all fits under the standard spoiler. I'm particularly fond of the clean lines of the narrow body and retractable spoiler and would sacrifice any further horsepower increase to avoid a big tail.

Anyone out there who can share their experience on the C2 or C4, either good or bad? Given that TPC is a long way from Perth, Australia and that there are very few UniChip experienced engineers here any assistance would be greatly appreciated. My next step will be to contact TPC and see if they have some ideas. Maybe get a replacement chip from them...

Thanks

Neil

ilko

Well I guess I'm obligated to chime in...

I have no issues with flat spots at all. I'm not really into drag racing so I can't say I've done a ton of hard launches, but I haven't noticed anything. My experience with the supercharger that came with my car is that it provides a lot of torque off the line and well into the 5,000 RPM range. Then it fizzles out. But the power delivery at least in my case is very linear and smooth.

My car has the older software, not unichip, and have no intercooler. The SC kit was installed in 2002, and has been on the car for 15K miles.

I believe you can fit the intercooler without the need of mounting a fixed wing. I've seen it on a 993. You might want to contact TPC to confirm.

964speed

Ilko is probably the guy you should speak with as he is currently running a TPC supercharger and has a wide range of knowledge and experince with theses set ups.

964speed

wow beat me to the punch!

BlueHeeler

There is a red light and siren on his computer that goes off everytime someone posts "supercharger" or "TPC" in the 964 forum. It is the modern age batphone.

wellcraft290

I am waiting to see these posts..

ilko

964speed

we need to resolve the battle between SC and turbo. I only wish SC's were cheaper and more readily available from multiple sources.

rotorheadcase

Thanks Ilko, I had expected a reply from you!!

As I understand from the seller the issue is with the C4's specifically. He has be told by a local specialist that the C4's PDAS cannot keep up with the amount of power generated at a hard launch and the flat spot is as a result of that... just doesn't sound right to me.

Any C4 owners or specialists want to chime in? I seem to remember a couple of Rennlisters installed the kit on C4's.

I can get the kit for around US$5000 so I think it could be a good deal if I can be sure this issue isn't systemic of the product and can be fixed.

Thanks

Neil

sturm

Have you got a install quote? I've been quoted $2000-4200usd for installation.

'93RSA 3.8

rotorheadcase

No qoute yet, but I'm heading down to see my local Independent this morning and see if he's done anything similar before. A 2k bill I could live with but 4k seems pretty steep to me for what is essentially a bolt on kit.

Neil

ilko

Just FYI, the previous owner of the car paid the equivalent of 10 hours in labor back in 2002.

I can't comment on the PDAS issue. The 964 AWD system is pretty complicated so who knows...

raspberryroadster

i agree with all your comments....i have had 2 supercharged cars (1 from the factory - 1 after market install).
in my view for mild to mid boost install a sc'd system will ultimately be cost effective if space in the engine compartment permits. superchargers tend to be easier to maintain (no plumbing, no BOV's, run cooler). the efficiency of a heat waste generated turbine(turbo) comes only into play at high boost installations......bolt on supercharger has more appeal to me than a cut into my exhaust manifold turbo install.
BUT these are high compression engines - so key is low boost.
*********************
CAN I ADD NEW DIMENSION (as in my former life with american muscle, running this was common and i know a lot of b'mers and jpnese whips are also on it)...NOS, nitrous , spray (wet or dry) to a properly prepared engine adds same power increase/adds no more heat/stress as forced induction.
installation cost of a nitrous kit is less than 5 figures -key is tuning and understanding high compression=very low power add.

I am presently trying to understand why this install has not been considered-dealt with on this forum....the previous posts here were a long time ago and the facts are:

- NOS is a cheaper install (like i am talking fractions)
- NOS is non-invasive per a turbo install
-set at proper spray it adds no more stress/heat inducement on an engine than forced induction (ie turbo or supercharger)


http://www.youtube.com/watch?v=Y5ndLAqIvzg

certainly a "ricer mentality" to this install...but a worthy candidate in the forced induction debate!
http://www.youtube.com/watch?v=rmNy-ajRV0U

sturm

I'm still pounding away on this

A local shop called TPC and was given 28hrs to install!? Plus 7hrs for the intercooler!!
They were the $4200 quote so that is a shop rate of $120/hr

Another "TPC approved shop" was at $3000 But they really aren't a "Porsche shop". Lots of Hondas/Jettas/Subarus

The shop that removed it (its a used unit) said $2000; but they're 1200 miles away.

Just looking at it spread around my living room I can't imagine 35hrs of work; there's just not that many pieces.

'93RSA 3.8

wellcraft290

rasberry I really don't understand you concern with turbo vs supercharger. They both produce heat and probably equilvalent amounts. So what is yoru theory that s/c are better? because they cut into the exhaust where the boost producing system is below the motor or to the side rather then on top of it?

I mean to call a turbo invasive compared to a s/c were you need to take off the intake manifold etc. I rather have my exhaust messed with then the top of my motor. Also most if not all besides the Kenne belle system are designed almost like turbos in their design except run off a belt then air pressure.

Just curious besides owning 2 s/c cars what is yoru expertise? I am not an expert by anymeans but can use common sense.