CTSC New Install Questions

[Hagasan]

Damn, Just realised that the beginning of my post was lost when I attached images!!

I just finished installing my low boost CTSC this weekend. All appears to have gone well with no leaks or bangs!! I have driven the car gently on the way to get some fresh gas. You can feel it wants to go quicker but I'm resisting this for now...

My car is a 96 but here in the UK that's OBD1. I have OEM 02+ headers, Prospeed Sports cats (I believe they are 300 cell) and an aftermarket UK produced exhaust. I have the OEM airbox and air filter. I fitted a new air filter and a new fuel filter. With my SoS pressure gauge on the filter I'm getting 45 psi at idle.

So before I feel comfortable driving with any conviction I'd like to ask a few questions.

1. When measuring for a safe AFR where are you actually measuring from? I'm sure the dyno guys will know what they're doing but I just want to be aware of the correct most accurate method. NSX's are not so common and the shop probably hasn't run one before..If it is just a probe in the exhaust which side? Left or right (from the rear), does it matter which?

2. What is the correct AFR values for specific ways of measuring?

3. What are the fuel pressure variations. Lowest to Highest?

4.Any other things to be aware of?

5.What do you actual adjust to alter pressure or AFR. What is it that you alter, what part and how?

6. If fitting an AFR gauge is the sensor put before the CAT or after and again does it matter which bank?

Sorry these are newbie basic questions but blowers with NSX's are a rare thing over here. Maybe three others!!

Thanks

 

[USAFguy22]

1. I just use the standard AEM wideband mounted in the same general location as my stock o2 sensor on the front bank.

2. Cold start it's around 13:1, cruising is ~15.5:1, under load it's 10.5-11:1 which is very safe. I have intake, bored tb, headers, hi flo cats, and exhaust

3. Fuel pressure is around 50 (or 60?) under normal driving, then bumps to 100 I believe under load

5. If its the standard low boost kit then everything is pre set the way it should

6. There's directions on about how far down the header to weld the bung. It doesn't matter which bank but I found the front bank easier to access.

 

[kookoo4nsx]

Under max boost up to 12 + - is good for sc. 12 or under AFR for turbo at max psi.

 

[MvM]

When I had my CTSC Low Boost installed, I also had a AFR-wideband sensor installed IN FRONT of the cat.
Display is mounted on my console (It's a Zeitronix unit).
I also have the fuel pressure gauge from SOS installed above the fuel filter.
At idle and with the stock fuel pump it reads about 40-42 PSI (around 900 rpm).
I do not really now what the fuel pressure is under load, but it should be way higher.

AFR should normaly be at around 14.5-14.9 under normal driving.
Under boost it should be much lower, around 11.2-11.7.

Your CTSC comes with a fuel pressure regulator (FPR), it's normally mounted against the wall of you trunk.
There is a small Allen screw there which you can use to adjust your base fuel pressure.

As a warning, I have driven my NSX with the Autorotor for about a year now. And even though I thought I had everything figured out things went wrong. Don't know what happened yet, but it won't be cheap.

I just had a Walbro and heavy wiring installed, put in a IAT- and boostsensor and had the AS Motorsports phenolic gasket installed between engine and manifold.

I think it depends on your style of driving as well. I did a lot of track work last year and used the CTSC to it's full potential, happily chasing M5's. I probably should have been more careful.

Good luck with the CTSC, it can be very addictive...

 

[Hagasan]

I had my car on the dyno the other day. It's a Land and Sea Dyno.

First run was quite disappointing... well very actually!! The guy did a 4th gear run and it only maxxed at 244 bhp! AFR were low 11's and touching the tens...

I showed him a plot from a friends car that recorded 365 bhp. His car was run in 3rd gear so we tried another. This time we got 344 bhp, still quite low AFR's and disappointingly only about 5 psi boost...

A little dejected as I have OEM headers, high-flow cats and an after market exhaust I expected a bit more. I also has a 6-speed box with NSX-R final drive.

I had a think to recheck the drive belt. It felt quite loose so I tightened it to a definite 90 degree twist as per the instructions. Up until then the car had been run for a gentle 40 or so miles so I guess it would have broken-in/stretched in that time then we did another run....

The dyno guy on this run said "f***in hell" as he ended the run! I wasn't sure what his reaction was saying as he said nothing until he walked around to the dyno computer to look at the graph... 388 bhp and 287 lb.ft torque!! Boost was now a bit over 7psi so the belt must have been slipping quite a bit. We are at only about 200ft above sea level . AFR's were for the most part steading at 12.1 to 12.3 then dipped to 11.7 and towards max rpm.....

We did another run afterwards where I tried to get the AFR's below 12 by setting the Fuel pressure at 66 psi (with the vacuum pipe removed from the FPR). Nate at CT said 62-66 psi is the typical setting with this method... anyway the last run with the slightly increased pressure got the AFR down maybe a decimal point but that was it. I didn't want to keep upping the pressure beyond where it was as on boost it would be sky-high....


I sent the plot to Nate and he said the "the plots look good actually" He commented that the AFR looked amazingly smooth and asked if there was some sort of averaging feature on the dyno software. I have no idea at the moment.

I have asked him "So you consider what you see to be perfectly safe to play around on the road with "all day long"?" but haven't received a reply yet

Incidentally. The dyno used a sniffer in the left from rear tail-pipe...


So what do you guys think of the results?

 

[NetViper]

Under max boost up to 12 + - is good for sc. 12 or under AFR for turbo at max psi.

Why would the "good" afr be different for a turbo vs sc?

 

[goldNSX]

I had a think to recheck the drive belt. It felt quite loose so I tightened it to a definite 90 degree twist as per the instructions. Up until then the car had been run for a gentle 40 or so miles so I guess it would have broken-in/stretched in that time then we did another run....

You'll have to re-tension he belt several times when it was new. There's only a narrow path between good tension and overtightening it.

Looks good!

 

[Silver Surfer]

Cracking!!!!

What's the car like now to drive with the extra 100bhp?

SS

 

[Hagasan]

Cracking!!!!

What's the car like now to drive with the extra 100bhp?

SS

I haven't driven it properly yet... I left the dyno with some items still to fit so didn't give it any beans yet and been busy with work the last few days... Once there is some dry weather I'll take it on some country twisty roads...