Here's the plan, its not set is stone, but is likely to happen. i 'm starting with a 1991 vert motor. It is already streetported and driven daily, but I want MORE.



I plan to enlarge the port, bust still retain some low end torque, I am building my own turbo manifold and will prolly go with a smaller turbo for the quick spool, I am going to run renisis rotors with 4MM seals, yes 4 and yes they do exist. so...



4mm seals

big port

10.1 compression rotors

lets say 8psi to 10 psi boost

straight through exhaust

fmic

cold air intake(real not rice)

msd ignition

nology wires

supra gretag 6 speed tranny and kazz diff

I'm in the process of building stronger half shafts, even stronger than turbo.



so what should I expect to pull out of this?

 

If 4mm seals do infact exist, I've got some old rotors that could have used a set.

 

i could get all the way up to 6mm . its from a place in Canada.

 

You are definitely thinking out of the box



Renesis rotors are hard pressed to hold a 3mm apex seals let alone a 4mm. Talk to board member Robbomaz, I believe he ran 3mm apex seals in a periport using FE rotors. There is not as much material as you think when milling an FE rotor to accept bigger seals. You should be able to get by with 3mm though for your diabolical plan



The FE rotors are 10 to 1 compression ratio if I am not mistaken. And to run 8-10 pounds of boost you would have to use an insanely high octane fuel, or water injection and much ignition timing retard to prevent detonation.

 

School me if Im wrong....

Going with higher compression is usually for NA, while turbo or supercharged want less compression.

When going to higher compresion the volume of air and fuel is reduced, while on NA its more efficiant ,with charge air all the compreesion loss is made up by the boost

Also higher compression from the motor build makes it prone to higher temp and detonation and more so when boosting.

It was my understanding that lower compression for charged air allows the boost to provide more air and fuel per cc and lower ignition point. More air more fuel more power. Why inhibit the benfits?Higher compression rotors reduce cc and incourage pre-ignition.Less power for the work involved.

This is just book read thoughts so I have no practicle experience.

 

l8t apex, have you ever driven a car with high comp, and boost? If not, you need to, you'll never go back. The high comp helps the turbo spool faster and you don't need as much boost to make power. And the whole detonation prob is why I'm goin with the msd, I'll have more control.



twstdmtl, your right about the compression, I checked again, some one else said 10.1, but mazda says 10 so thats what i'll go by. and thanks for the apex seal advice, I really had no Idea if it would work, thats why I posted, I'll get in toutch with the guy you mentioned.



And another Q, I've been a N/A guy untill here recently when I drove a boosted 240sx. DAMN, I fell in love. The question is, when porting a turbo motor, where should I go with the exhaust port? up any at all, or just down? I know you can't go up too far or you'll get overlap.



And with all the reading I've done, I'm guestimating about 400hp with 7psi boost. correct me if I'm wrong.

 

No I havent.

I 've driven Porche Turbo, Ford Probe, My Single T, T2 Rx7,86Tbird,...

but the manufacturer has made them with lower compresion than NA version.

Well except the Fd in which I think mazda put 9.5:1.



I support you.Actually I ask this very question to Leonard Hughes the owner of the Candies and Hughes funny car. About 6 months ago.

But you kinda got his answer in a round about way.But I was thinking the same as you.

 

Hey gimma some info or ideas on that tranny...I thought about that too but I wont venture into the time it takes.I hate all Mazda trannies.The synchros are made to go to the grocery store only.

How much investigating have you've done?

 

I have heard that there is a guy that makes a kit to adapt the gretag to a 13b. If I can't find him, them I'm going to check into getting the Rx8 tranny. I've heard good stuff about them. But I'm not sure if they'll fit the s5 block. maybe.



as far as research, I've really only checked the tranny itself. We took the gretag out of my friends supra and the tranny out of my other 7 and took them both apart to compare. The supras is LIGHT YEARS ahead of the 7's. but I have yet to get hold of a rx8 tranny. maybe soon. as far as the mounting to the 7, I have only heard about the kit to adapt it, but I am searching.

 

Yo Venom

Something to think about in regards to your project. I'm going to be running 3mm apex seals in my latest venture (street ported 13B Turbo II- for autocross/daily driving), but one of the things I looked at when making the decision was groove depth, rotor apex width and height. In other words because you'll have to cut your rotor to accept such wide seals (which in your case would be more than 4mm) you would actualy end up width a signicantly wider and more importantly shorter apex. And because you can't really go down deeper in the groove without also compensating with a longer seal you would be left with your seals more exposed with less material to support.

PK797 NYC