Engine power!

Mike Pass

Supporter
No 1. Replace the tyres with Avon cr6zz
No 2. Without the exact spec of what you have it is impossible to give any advice.
I have sent you a message (see top right of page)
Cheers
Mike
 
Exhaust primaries look like they are on the small size in terms of diameter.
double plane manifold on the engine probably works best at lower RPMs. Maybe a different intake manifold would work better. after that, its depends what the rest of the package is.
 
Exhaust primaries look like they are on the small size in terms of diameter.
double plane manifold on the engine probably works best at lower RPMs. Maybe a different intake manifold would work better. after that, its depends what the rest of the package is.
Where can I purchase the exhaust?
thank you
 

Howard Jones

Supporter
A standard Renault will live a nice long life up to about 325HP (crank). This is a easy chore with a 302 CI SBF. Go on line and find the specs for a Ford Motorsports 345HP crate motor. They have about 9.5 to 1 CR. Do a compression test on you motor and if you are about 125-135 psi, then you have enough CR to make 350 HP. Next is heads. What do you have on it now. Check out the heads on that Ford crate motor above. If you are near their spec (not much of a stretch because they are not really all that excotic) they have 1.94 intake valves and 1.64 exhaust. The heads are just bored for valves and with out any port blending. Just a nice new 3 angle valve job and a little basic blending around the valve pockets will yield you another 20 HP. Once you have that much done the cam and valve springs are next. A moderate cam suitable for road use up to 5800 RPMS is plenty. Go for about 280 degrees of duration and .525 inches of lift. That will do it. Keep what you have for a intake and carb. The header you have are fine for 325 HP so keep them also.

Call Comp Cams and speak to their tech advice and tell him what you are trying to do.

One last thing. If your Renault is standard then you should not go much beyond a nice pump gas street spec as I have suggested above. Once you go beyond 350HP then things get expensive with GRBX's. First on that list is a single piece input shaft upgrade and at the same time a limited slip diff. I am in love with Quaife TBD's.


Those are BF Goodrich TA tires you have. I am guessing you have 15 inch wheels to go with them. The tire question is a whole other discussion. They will be fine on a road use car with a nice moderate engine.

My advice is not to get carried away with power until you have a full understanding what another 100 hp beyond 325 will require of the rest of the cars systems.
 

Rune

Supporter
I believe the exhaust pipes is 1 3/4" and that is enough for 450hp so concentrate on cam and webers then you will have enough for the transaxle.The gear box is the limitation .
 
A standard Renault will live a nice long life up to about 325HP (crank). This is a easy chore with a 302 CI SBF. Go on line and find the specs for a Ford Motorsports 345HP crate motor. They have about 9.5 to 1 CR. Do a compression test on you motor and if you are about 125-135 psi, then you have enough CR to make 350 HP. Next is heads. What do you have on it now. Check out the heads on that Ford crate motor above. If you are near their spec (not much of a stretch because they are not really all that excotic) they have 1.94 intake valves and 1.64 exhaust. The heads are just bored for valves and with out any port blending. Just a nice new 3 angle valve job and a little basic blending around the valve pockets will yield you another 20 HP. Once you have that much done the cam and valve springs are next. A moderate cam suitable for road use up to 5800 RPMS is plenty. Go for about 280 degrees of duration and .525 inches of lift. That will do it. Keep what you have for a intake and carb. The header you have are fine for 325 HP so keep them also.

Call Comp Cams and speak to their tech advice and tell him what you are trying to do.

One last thing. If your Renault is standard then you should not go much beyond a nice pump gas street spec as I have suggested above. Once you go beyond 350HP then things get expensive with GRBX's. First on that list is a single piece input shaft upgrade and at the same time a limited slip diff. I am in love with Quaife TBD's.


Those are BF Goodrich TA tires you have. I am guessing you have 15 inch wheels to go with them. The tire question is a whole other discussion. They will be fine on a road use car with a nice moderate engine.

My advice is not to get carried away with power until you have a full understanding what another 100 hp beyond 325 will require of the rest of the cars systems.
Thank you for contacting us. I learned a lot. My engine E7TE runs only 6000 miles. There should be compression.
peace
 
Firstly change your tyres!, check the date stamp, im guessing they are well over 10-15 years old and dangerous. BFG's were pretty poor when new, you need Avons.

Second as has been said below 350bhp and your transmission will be fine . The easiest route to this sort of horsepower is some big valve aluminium heads from AFR (165) or Edelbrock. You will need an uprated camshaft and new tappets and roller rockers to match. Your carb if 600CFM or above will be sufficient to make 350 HP as will your exhaust, plenty big enough. You will need at least 9.5:1 compression, but better with 10 or 10.5 :1 and this will mean new pistons. You will then need to rejet your carburettor.
The whole rotating assembly will need to be re-balanced with your new clutch because you will need an uprated one to cope with the torque if you just have a standard renault 21 turbo clutch.
 
Well, if you want to upgrade your power, yes, the transaxle is the limitation. But you should also look at your brakes - you'll need to stop too :)

More power doesn’t require more braking does it, it’s still the same car being stopped?

Unless the car is getting heavier or there is a sudden change in use to a track car then surely the existing (assuming they work fine now) brakes will be absolutely fine?
 

Chris Kouba

Supporter
More power doesn’t require more braking does it, it’s still the same car being stopped?

Unless the car is getting heavier or there is a sudden change in use to a track car then surely the existing (assuming they work fine now) brakes will be absolutely fine?

If you have the ability to put more energy into the car at a faster rate (motor has additional power), you should absolutely consider the ability to pull that same energy out of the car at a faster rate (bigger brakes).

A few horsepower here and there probably won't make a difference, but I can tell you about a ride I took in a "tuned" WRX where the motor went from its 225 bhp to 425 well-tuned bhp through boost and intercooling, and the brakes were not touched. They lasted about 3 hard stops and would have made for an abysmal track experience.
 

Howard Jones

Supporter
Kinetic energy = mass X velocity squared. A little faster is a lot more heat! Arriving at the end of your chosen straightaway at 80 mph instead of 65 mph will produce more than 50% more heat.

Build the car around the gearbox and the brakes..............then motor and tires. Not as sexy but a lot better plan. IMHO of course.........
 

Mike Pass

Supporter
For more noise change to smaller straight through silencers.
For more power get some good aluminium cylinder heads such as Edelbrock Performer RPM or AFR 165 or 185. Usually worth up to 90hp increase over standard iron heads on a 302. Check out the list number of the Holley carburettor to see exactly what you have - you will find it on the choke tower on top of the carb.. It looks to be a vacuum secondary type carb with new metering blocks. Inlet manifold looks to be a dual plane of some kind but can't read the logo.
Cheers
Mike
 
Thank you for your advice. I'm thinking of upgrading the aluminum head and cam of the Edel block and the Holley Sniper efi. Which is better, aluminum head or cam? Do you know the part number?
 
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