Turbos on a Seven

[Klasik-69]

Whether it's the Zetec, Duratec or Ecotec that can produce X amount of HP isn't really the main concern, it has more to do with which on can be fitted to the Caterham S3 chassis along with the tranny mated to the power plant. Maybe this is not the issue for those of you with larger chassis that can accommodate either turbos or superchargers, or those who have Westfields or other similar generous engine bays, but it is for me. I've heard back from several UK shops who prefer turbos for the Zetec vs SC but who also say the SC will work well if it will fit better. Nobody sells a Zetec "kit", and in fact I can't even find an S3 with one installed (yet). I would have to initially lower my cr down to 9.5, 10.0 max, and likely go with forged rods & crank, HD rod, main & head bolts. Forged pistons if mine aren't already, modify the front nose cone to be 3" to 4" longer up front to allow space for the intercooler and then remap the ECU. All of it is possible. Does it make sense ? Not sure. Cost ? Not sure. Also, if I gained 100 rwhp, what gain in top end on a long straight would I gain vs my current 183 rwhp ? Now about 130 + or -...........150 ???

[WestTexasS2K]

Klasik I was under the impression that you need to run lower compression for all forced induction applications and found out that isnt always so. When we built 7evins car with the Rotrex we lowered compression ratio from 11:1 to 9:5 we found out later that really hurt the power. Oscar Jackson informed us that the way the pulse waves of the Rotrex supercharger likes the higher compression ratio. He sent us some tables and charts to prove the point. I cant say I completely understood the data, but when 7evin rebuilt his engine he reinstalled the 11:1 and got a good kick in the power band. He is running 23psi on 11:1 engine on E85. The Honda guys are running 10 psi on the stock 11:1 on pump gas motors with no real problems.

 

Turbos will make more power for sure. With new turbo technolgy lag is virtually gone and you will make more torque overall in the powerband. Heat is the biggest issue in my opinion. The Rotrex just doesnt generate as much heat as the turbo.

[jlumba81]

Found some zetec supercharger kits. Plumbing will have to be modified to fit a 7 though.

 

http://www.shopsupercharger.com/p-914-ford-focus-zetec-procharger-ho-intercooled-supercharger-tuner-kit-2000-2003-1fk202-sci.aspx

 

http://www.shopsupercharger.com/p-915-ford-focus-svt-procharger-ho-intercooled-supercharger-tuner-kit-2000-2003-1fk302-sci.aspx

 

http://www.fawcettperformance.com/product_info.php?products_id=405

[westy turbo]

I understand that turbo will take "more" in any case.sc as said above can operate on

stock cr/internals as its a low psi set +water injection and ecu tune.u can forged

the engine and take it on a higher psi pulley.

 

The sky engine would be my long future engine..just love it!,ill wait for the gen3

twin scroll one to hit the brackers

[Klasik-69]

Found some zetec supercharger kits. Plumbing will have to be modified to fit a 7 though.

 

http://www.shopsupercharger.com/p-914-ford-focus-zetec-procharger-ho-intercooled-supercharger-tuner-kit-2000-2003-1fk202-sci.aspx

 

http://www.shopsupercharger.com/p-915-ford-focus-svt-procharger-ho-intercooled-supercharger-tuner-kit-2000-2003-1fk302-sci.aspx

 

http://www.fawcettperformance.com/product_info.php?products_id=405

 

Thanks for the links. I don't know which is more compact, the procharger in these links or the Rotrex. As you well know, space is at a premium, especially in the S3 chassis

 

 

Klasik I was under the impression that you need to run lower compression for all forced induction applications and found out that isnt always so. When we built 7evins car with the Rotrex we lowered compression ratio from 11:1 to 9:5 we found out later that really hurt the power. Oscar Jackson informed us that the way the pulse waves of the Rotrex supercharger likes the higher compression ratio. He sent us some tables and charts to prove the point. I cant say I completely understood the data, but when 7evin rebuilt his engine he reinstalled the 11:1 and got a good kick in the power band. He is running 23psi on 11:1 engine on E85. The Honda guys are running 10 psi on the stock 11:1 on pump gas motors with no real problems.

 

Turbos will make more power for sure. With new turbo technolgy lag is virtually gone and you will make more torque overall in the powerband. Heat is the biggest issue in my opinion. The Rotrex just doesnt generate as much heat as the turbo.

 

One of the shops in the UK said they didn't think with the cr I have that I would be able to go above 10 or 12 psi, but that kind of boost with the engine I have would yield great power. They didn't put a number down as to "great power". If I do a complete tear down and install the right components, I could get into the 320 hp range, maybe. How reliable would that engine be ? not sure, most of my running is on the track and I'm usually using as much power as I can squeeze. However, with around 320 crank, maybe 270 rwhp, I might not need to squeeze it that hard.

 

Also, I'm seriously thinking of mounting the intercooler on the right side of the engine bay. It may not be as efficient as a front mounted but it would be close. The piping would be much easier and it wouldn't compromise the other front end components as much. Also, much easier than making a new nose cone for the car. Would I need an oil cooler ? Some seem to think so.

[Croc]

..... if I gained 100 rwhp, what gain in top end on a long straight would I gain vs my current 183 rwhp ? Now about 130 + or -...........150 ???

 

 

Hold on a moment. So you add all this power dont you still run up against a gearing issue? Assume a diff ratio of 3.62 and the usual Caterham 6spd 1:1 ratio in 6th then you would still max out at your redline at the same top speed (135-138mph) unless you (1) increase your rev limit or (2) change your diff ratio to the 3.38 or 3.41 or even 3.15 (if my memory of Caterham diff ratios is correct).

 

Are you trying for (1) alone or for both (1) and (2)?

[Klasik-69]

Hold on a moment. So you add all this power dont you still run up against a gearing issue? Assume a diff ratio of 3.62 and the usual Caterham 6spd 1:1 ratio in 6th then you would still max out at your redline at the same top speed (135-138mph) unless you (1) increase your rev limit or (2) change your diff ratio to the 3.38 or 3.41 or even 3.15 (if my memory of Caterham diff ratios is correct).

 

Are you trying for (1) alone or for both (1) and (2)?

 

You're absolutely correct.............except my car has a 5 speed and 5th is OD. 4th is 1:1. But you are correct with my 3.62 rear end ratio. The problem I've been having is with the 205-50R15 tires/wheels, I run out of 4th but run short on grunt in 5th. So I went back to the 13" wheels and went with the 20.5" OD bias ply Hoosiers. I need more revs at a lower speed to be able to use 5th gear. Not sure that will work but mathematically, it should. According to my calculations, I would hit 121 mph @ 7200 rpm in 4th gear, 143 mph @ 7200 rpm in 5th gear.

 

I have squeezed (tail wind, drafting, and farting) 131 mph, and I think it was slightly downhill at Roebling, not to mention coming out of turn 9 like a crazed lunatic on crack. :willy_nilly: I have already ditched the air brakes (windshield and watermelon sized headlights).

 

I would love to be able to hit 140 in the 7. I'm not sure it's possible, but I can try. If you think I'm all wet on this, please let me know. You know a heck of lot more about these cars than I do. I'm learning as I go. That means making mistakes along the way.

[WestTexasS2K]

140 is easily doable. My Ultralite that i first supercharged car I did ran 9 psi on stock motor and it would do 140 on a few tracks like Road Atlanta. That car pulled 260 or so on the dyno. That was using a 4:11 diff with 26" tall 17" tire. Honda has a 9k rpm redline. The acceleration out of the corners is where you can really can shave the lap times.

[Klasik-69]

Since there has been so much talk about the Zetec's oil pump issues at higher rpm's, I have redlined mine at 7200 to be on the safe side. I don't need to trash the motor over an oil pump issue. Jon @ Caterham USA told me the engine is good all the way up to 8000 rpm and I believe him. So I figure 10% below that is a good safe bet. Honda engines are so well built and balanced that 9K is no effort. They're used to building bike engines that rev into the 15K to 18K and supplied all the engines for the Indy cars for a few years without one single engine failure. If I had to start from scratch, I'd go with the S2000 engine and SC. BUT, I have what I have and I still think this is a good engine with very good power. I just need a little more, but don't we all just need a little more. It's never enough if you're competitive. I do believe that at some point this little car can become unbalanced with too much power. A scalpel can become a boom axe, results can become ugly.

[Kitcat]

The Honda engine is too tall to fit under the Caterham bonnet anyhow.

[Croc]

You're absolutely correct.............except my car has a 5 speed and 5th is OD. 4th is 1:1. But you are correct with my 3.62 rear end ratio.....

 

I would love to be able to hit 140 in the 7. I'm not sure it's possible, but I can try. If you think I'm all wet on this, please let me know.

 

 

No I definitely dont think you are wet and I will go out there saying I believe you can get over 150mph. So lets assume you make more than 270hp. The CSR with that horsepower in the Cosworth Duratec, a standard 6 speed Caterham box with the 1:1 6th gear, and the 3.41 diff was tested to 155mph at a redline of 7800rpm (for that engine). So your ideas are ballpark achievable if you can solve the engine problem and you change a diff ratio to either the 3.35 or 3.41 alternatives.

 

 

I love hearing from other people on this forum who are as bonkers as I am! :rofl:

[Klasik-69]

No I definitely dont think you are wet and I will go out there saying I believe you can get over 150mph. So lets assume you make more than 270hp. The CSR with that horsepower in the Cosworth Duratec, a standard 6 speed Caterham box with the 1:1 6th gear, and the 3.41 diff was tested to 155mph at a redline of 7800rpm (for that engine). So your ideas are ballpark achievable if you can solve the engine problem and you change a diff ratio to either the 3.35 or 3.41 alternatives.

 

 

I love hearing from other people on this forum who are as bonkers as I am! :rofl:

 

Thanks for the input (and a check on my sanity). I think I can achieve the resulting gear ratios by the selection of tire diameters easier than changing the diff. ratio. I'll know better once I get the car out on the track with the 13" wheels/tires. For one thing, the weight went from about 65 lbs/wheel with the 205-50 R15 to about 20 lbs on the 13" wheel & 20.5X9.5X13 tires. Acceleration should be pretty brisk and upper end speed is still a mystery.

 

On the tranny issue, I have never heard of the SADEV sequential transmission. I looked it up and found they are a French company with a lot of transaxle, transmission and differentials for race cars in both 2WD and 4WD but couldn't get details on the 6 speed application for the Zetec. There is a company in England that represents them and can make adapter mounting plates to mate up any SADEV tranny to any engine. I wasn't sure if SADEV had specific trannies for the Zetec. Also, not sure how compact they are. I looked at the space around my transmission in my S3, and it's a tight fit for sure. I also wondered about the placement of the shifter vs. the T9. Have you seen any SADEV mounted in a S3 chassis ?

[westy turbo]

measure ur tunnel/box and then ask via mail- bgh,drenth,elite - pdf diamensions.

[Croc]

I also wondered about the placement of the shifter vs. the T9. Have you seen any SADEV mounted in a S3 chassis ?

 

Blubarisax has a sadev so can answer specific questions on his experiences and would have the name of the guy he bought through in Germany who help lighten his wallet.

 

My other recollection is a Sadev was put in an S3 chassis by Carl (last name who escapes me) who runs the Seven Speed website. He goes by the name Mad Hatter on Blatchat.com and occaisonally pops up on USA7s. I would seek him out through his Seven Speed site.

[Kitcat]

Wow, a 65 pound single wheel tire combo on a seven, are you sure? So you saved a total of 180 lbs by switching?

 

I had a 265x19x45 on the back of my M3 that weighed less. My 15'' Birkin wheel w/15x205x50 Toyo was about 32 lbs. Both the wheel and tire were heavy and, like you, I dropped down to low 20's w/liteweight 15'' 949 wheel with light weight Avons 15x195x45.

[rnr]

Wow, a 65 pound single wheel tire combo on a seven, are you sure? So you saved a total of 180 lbs by switching?

 

That is one of the negatives of having large wheels on the Ultralite. I run 235/275 F/R and just the rubber by itself weighs a hundred pounds. Measuring the weight with the wheels is just going to make me sad.

[Klasik-69]

Wow, a 65 pound single wheel tire combo on a seven, are you sure? So you saved a total of 180 lbs by switching?

 

I had a 265x19x45 on the back of my M3 that weighed less. My 15'' Birkin wheel w/15x205x50 Toyo was about 32 lbs. Both the wheel and tire were heavy and, like you, I dropped down to low 20's w/liteweight 15'' 949 wheel with light weight Avons 15x195x45.

 

 

Well, I may have been smoking something funny when I figured 65 lbs. I went back and looked at the Hoosier specs and the SM6 tire weighs 19 lbs and my wheels weight 14.5 lbs. That adds up to 33.5 lbs plus a little weight for the air inside. Maybe closing in on 38 lbs. The 13" wheels/tire combinations feel like 20 lbs, give or take. So I saved around 72 lbs, which means I can now eat a large pizza before jumping in the car without any negative effects.:flag:

[Klasik-69]

Blubarisax has a sadev so can answer specific questions on his experiences and would have the name of the guy he bought through in Germany who help lighten his wallet.

 

My other recollection is a Sadev was put in an S3 chassis by Carl (last name who escapes me) who runs the Seven Speed website. He goes by the name Mad Hatter on Blatchat.com and occaisonally pops up on USA7s. I would seek him out through his Seven Speed site.

 

I hope he has an S3 chassis too. I'll send him a pm to see if he can shed some light. thanks for the tip.

[westy turbo]

[WestTexasS2K]

I dug up a old video of 7evins car on dyno with the Rotrex.