GTUs

I seconded to that inquiry.



plus how much did it cost for machining?

pengaru

I'm guessing they machined the apex seal grooves to run the larger (older) apex seals?



It should be possible to run the renesis seals without machining anything, but the seals for the renesis are quite pricy, for the whole kit.



Theres also some concern with the renesis seals not being able to tolerate the peripheral ports on the previous series' rotor housings. Some people have claimed there is a risk of them bending and binding up in the ports, hence why someone would want to use the previous seals which are larger, requiring machining.



Hopefully Robbomaz can clear it up for us

crispeed

I've ran 9.7 compression rotors on turbo applications without any problems. I've made close to 600rwhp and ran over 30psi with no drawbacks but only gains over the lower compression ones. Precise tuning is the key no matter what the compression is.

FikseRxSeven

hmmm 600 hp..... ill take his word

13BAce

I heard from somebody a few years ago that crispeed was doing that, but I never said anything because I was told that it was a secret. I guess I'm not special after all.

BigTurbo74

can u tell us the setup you were using??? is it the engine that you ran a 9.2 in??? unless it's a secret

13BAce

http://www.fullboost.com.au/cars/featureca...hris_intro.html

I think he's now running an FD motor with a Cosmo intake manifold.

Robbomaz

How to put it simply (& avoid typing heaps! )

There is a mechanical limit to chamber pressure, which is the boost + CR.

Now heres some broad generalisations:

High CR/lower boost will show more midrange and equal power to a low CR/high boost setup. Off boost performance and the spool-up will be significantly better.

So what? Most turbo cars (even ours!) spend over 70% of their time off boost is why!



For flat out (drag, circuit etc) the flat response from a low CR is not an issue as the car spends 90% of it's time at WOT.



The difficulty (if it can be called that) is the tune must be far more precise on the high CR unit. But like crispeed said, the tune should be right no matter what.

My 20B Cosmo for example is richer and more retarded than our Fd racer. I want the 20B to go a few years between rebuilds, the FD gets a fresh engine every season.

Robbomaz

We probably could have used the renesis seals, but this was not something I could be definate about, given that we knew the seals did not cross a port as designed.



The renesis seals may well be fine but that was not a risk I wanted to take with this guys motor. He is an unsponsored racer (apart from our discount price ) and needed a season + package so it was decided to machine the grooves to take proven seals. I'm sure someone will use the new seal in an old motor soon. I believe the gas edge is better sealing on renesis seals.

andynogo

Yes but the renesis seals are about half the height of the older seals, so will likely flex more when encountering the exhaust port in a pre-renesis motor.



Flex = bang!