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Discussion Starter #1
I am planning out my next round of mods and need some advice on a few items.

Note: I will be staying with the stock fuel system for now.

Current Mods:
TKO 2.5" Exhaust
Apex-i Intake
MBC @ 14psi

Planned Mods:
TKO 2.5" Downpipe
ATS CT27 Turbo w/tuned ROM & FPR
ST205 A2W Intercooler
Water Injection
Electronic boost controller

I want to maximize my Torque curve. I would like to achieve a wide, flat Torque curve that will pull to 8000 rpm redline.

I am thinking I will need to following to do this:
Shimless bucket conversion
Engle Valve springs
ATS adjustable Cam Gears
HKS Cams (which?)

My questions are:

1. Which Cams will let me achieve my goal the best?
2. Am I missing something in my proposed setup?
3. As long as I stay conservative on the tuning, will this setup be safe?

Thank you for your help.

Richard Williams
1994 Black MR2 Turbo
 

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I think 264 cams will be more than sufficient, however I have doubts that the ct27 will give you [email protected],000rpms. I could be wrong, but I think it dies off a tad toward the end of the stock redline, just not as bad or as early as the ct26.
 

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Discussion Starter #4
93smgturbo said:
I think 264 cams will be more than sufficient, however I have doubts that the ct27 will give you [email protected],000rpms. I could be wrong, but I think it dies off a tad toward the end of the stock redline, just not as bad or as early as the ct26.

I see what you mean, but the dyno's of the CT27 shown on the site have stock cams. Could this drop at redline be from the stock cams or the turbo?

Richard Williams
1994 Black MR2 Turbo
 

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I can hold 17psi to redline on the ct27 50 trim. I dont know how it would hold up with another 1000 rpm but Im sure it could hold it.

I would go with a 3 inch DP to get spool up and make more torque earlier.

Can you raise your rev limiter with the ATS tuned rom? I didnt think you could since its still based off the stock ecu. That would be nice though.

The drop at the end of the dyno is because of the cams, not the turbo.

we will have to meet up so you can drive my car with the ct27... Hopefully we can have an ATL mr2 meet here in the next few weeks. I cant make it to the superbowl party at Brian Hills house so maybe some other time.
 

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Cams aren't really necessary until you get to the 300rwhp area. Then by 350rwhp, it is very obvious you need some cams.
 

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Discussion Starter #7
93smgturbo said:
Cams aren't really necessary until you get to the 300rwhp area. Then by 350rwhp, it is very obvious you need some cams.

I realize that they are not necessary but I am looking to use them so that I can extend my torque curve to 8000 rpm. I am simply looking at maximizing the area under the curve while staying with the stock fueling.

Richard Williams
1994 Black MR2 Turbo
 

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Discussion Starter #8
Vrooom Psshhh said:
I would go with a 3 inch DP to get spool up and make more torque earlier.

Can you raise your rev limiter with the ATS tuned rom? I didnt think you could since its still based off the stock ecu. That would be nice though.
Yes, you can raise the rev limiter with the ATS tuned ROM.

Vrooom Psshhh said:
The drop at the end of the dyno is because of the cams, not the turbo.

we will have to meet up so you can drive my car with the ct27... Hopefully we can have an ATL mr2 meet here in the next few weeks. I cant make it to the superbowl party at Brian Hills house so maybe some other time.
Yea, we need to meet up. I am going to be purchasing my new mods in about a month, and want to get all the research done prior.

We need to do a mountain run...... :evillaugh

Richard Williams
1994 Black MR2 Turbo
 

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This is a recipe for disaster....

Flat torque curves to 8K and stock injectors do not mix. Allow me to present some facts:

Suppose that you build your motor with cams/turbo/IC/exhaust/intake manifold to give you a flat torque curve from the time you hit full boost to redline. Let's say for the sake of argument that this is 200ft/lbs of torque at the wheels. At 6K RPMs, you will be making 228rwhp and your injectors have 20ms of time to flow the required fuel to keep the engine safe. At 8K RPMs, you will be making 304rwhp and flowing 33% more air. However, your injectors now only have 15ms to deliver the required fuel. The combination of needing 33% more fuel and having only 75% of the time to deliver means that your injectors have to be 44% larger to make the same amount of torque safely at 8K than at 6K.

So, my guestimate on how much torque stock 440cc injectors can safely handle at 8K RPMs is around 130-150 ft/lbs to the rear wheels. Do you honestly want a setup that only makes a flat 150 ft/lbs of torque to an 8K redline?
 

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Discussion Starter #10
RickyB,

Very good point. I was not thinking in those terms. If I leave the rev limit alone, can cams help me level out the torque curve near redline? I would like there to be less of a torque dropoff near redline, as with the stock cams. Is this feasable, or no?

Thank you all for your feedback. I am still learning, and this is helping alot.

Richard Williams
1994 Black MR2 turbo
 
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