As per title, I have a tts supercharger on my car at the moment, it is a very old kit with a c30 supercharger, I have been getting only 5psi of late, and want more!

I have found a second hand (with v low mileage) c38-91, i spoke to tts today about a c38-81, which is more what I want power wise (not atronomical) but it is over twice the price of the one I've found, the c38-81 is said to run 400bhp, the c38-91 is said to run 500bhp, but I don't want anywhere near that much,

So can I just run a larger pulley on the larger SC to lower the boost and make that charger work, or do I spend an extra £1000 just to get one a bit smaller with slightly lower peak power output?

If I wanted to run it 'full bore' I would need 1000cc injectors, 4 bar map sensor and a couple of other bits, I don't want to have to buy all these bits as I only want 400bhp, which I can use all the stuff that my car has already...so bit backwards, but the cost is a massive factor.....

Need to know as the 2nd hand unit won't hang around long....!

 

Just get the 91, it has a larger mass flow rate at lower rpms so you will gain more through the power-band.
to get the boost you want you can change the pulley or if your using Flashpro you can limit throttle plate position via the TP maps.

I have a TTS kit with a c38-81, but I went ID1000 injectors straight away.

Also if your going to be going anywhere near 10psi make sure you DO get the 4 bar MAP sensor...I was using a stock sensor at 10psi and found in really cold weather i was boosting to nearly 15psi but the sensor was pinning at just 11psi..which obviously means that the fueling wasnt corresponding to where it should have been at the top end of the fuel map.

 

Ok, I'll do it! Thanks, what I'll probably do Is is run the 750's I have for the moment, and limit the boost with a larger pulley, where do I get a 4 bar map sensor? Will tts have these?

Quite excited to actually get my car going again with some real shove!

 

Good luck resisting the urge to up the boost once you realize what it's capable of!

 

ok found out today, it is a c38-91 with an 81 housing, not sure how that works, but its all good, went to have a look and pick it up tomorrow : )

what size pulley should i be looking at getting btw, im very lost with all that, i want about 400+ thankyou very much

dan

 

Dan:

Not wanting to start a stank but the C38-81 and -91 have a 10mm difference in length. Also I am pulling over 400whp with my -81 and it's only spinning at 101% at redline (8300rpms). I would be cautious, very cautious on this -81/-91 thingamagig. Having said that, a -91 will rock your S and I may end up doing this myself. Here is some pulley info:

At 9000 rpms:
95mm = 98.7% spin rate
90mm = 104.2% spin rate - Overspun 4.2%
85mm = 110.3% spin rate

J

 

Yes I am aware of the size difference, it was done because it came off a car that space was a premium (bmw m5) so had it custom made, whether it is or isn't I won't know 100% how/why until I contact the people he bought it from,

I don't really understand your point about starting a stank about the size, or why i should be cautious? If you could elaborate that would we great

As far as the charger goes Tts have heard about these so its definately a real thing, whether this one is a hybrid one is yet to be seen!

do you mean you think it's just a standard 81, and he has advertised it in a way to make it sound better than it already is? Whichever way you cut it it's still a good charger and worth what I paid I hope!

Still not 100% what those figures mean yet, but I'll take another look over them and try to work it out : )

Dan

 

There is no such thing as to big for your needs.

Can't wait to see the results.

 

Picked it up today, very happy bunny, will have to customise my bracket to make it fit and move the pulleys slightly so I get more wrap around on the charger to help eliminate belt slip, the back plate modification will be the worst part I think

Then move onto a larger intercooler setup, then get it mapped : )

 

What diameter pulley has it got on it at the moment?
Mine is 105mm on a c38-81 and hits about 11-12psi with restrictive intercooler/pipework and im running around 420bhp at the fly. If I were to increase the IC piping size and use a larger intercooler it would be around the 15psi mark.
Then with a 90mm pulley around 19-20psi.