MR2 Owners Club Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
47 Posts
Discussion Starter #1 (Edited)



Engine is a 5sgte 2.1L non stroked with custom ATS wiseco pistons.
ATS TD06 turbo with external gate, re-routed.
3 inch very unrestrictive exhaust.
Greddy sidemount.
Kelford 270 cams .
Kelford valve springs.
Stock intake manifold with TVIS removed and filled, larger throttle body inlet.
All intake ports matched and casting flaws removed.
Tuned on 98 RON octane on ECU master EMU.
Boost controlled electronically with ECU.

Do these figures look about right, I thought they look a little low. Do these dynapacks usually indicate lower than a dynojet?
It seems that torque is dropping off too much with RPM, its like it needs the torque curve shifting to the right, which makes me think perhaps it needs some tweaking of the cam timing, I thought cams hold power better than this? Boost also tapers off from 18psi to 17psi at higher revs. The engine is built to withstand 8000rpm and I would like it to hold power higher into the rev range. I was hoping for hp between 350 and 400.
I've attached the timing map, your thoughts, thanks in advance.
 

·
Registered
Joined
·
671 Posts
It is my opinion and I am no expert, but these numbers look OK to me, maybe you could squeeze 10-20 hp more out of the tune but I doubt you would be able to safely get to 400hp on 93US (98 RON) fuel.
 

·
Registered
Joined
·
618 Posts
Your setup is somewhat similar to mine. 5s crank, wiseco pistons, TD06. Big differences are cams - you've got 270s, I have 256s, although I'm going to swap them out to 264s. And intake manifold, I'm running a RacerX. Also, boost. My runs are at 20psi. So pull 20-25hp there. I also see a pretty big drop off at the top end, which is why I'm changing cams. However, with an intake manifold on yours, you might be able to get a fair bit more. Otherwise, the turbo really will be the limiting factor I think. A minor factor may be that I'm running 94 octane fuel.

Now, of course comparing different dynos is not really fair or equivalent. However, given how close that lines up, I think you're in the right ballpark.



Here's essentially the same setup on my car except a 2.0L on stock internals. Blew up on the dyno moments later, but that's another story.

 

·
Registered
Joined
·
6,057 Posts
As was stated, its hard to compare absolute numbers on different dyno's (unless they are dynojet's).

Looks OK for over all power.

Given your peak torque hit at 4500 lasting until 5500 rpm, I would expect peak power to come a little later than what looks like 6K rpm with a very fast drop off.

I have a genII basic CT20B setup (with stock exhaust cam retarded 6* in this dyno). My full peak torque hit 500 rpm earlier (smaller turbo would expect it to), but my peak power does not come until 6300 rpm.

http://carpron.com/multisite/v/Upload/califcarm/100_3361.JPG.html?g2_navId=xa8a91887&g2_GALLERYSID=706e401922bde8802c2ddbf341e02eb4

With your larger turbo and big cams, you should be able to hold torque flatter longer than you are showing. I would think you need to spend some time playing with the cams. Quick guess is your are too advanced (giving quicker spool, but killing top end power), and your lobe separation is too narrow (giving maybe slightly higher peak torque, but making the torque curve "peaky" with fast drop off). So maybe look at retarding your cams (especially exhaust cam), and widening your lobe separation to fatten the torque curve a bit more. Just guesses on what do to, of course.
 

·
Registered
Joined
·
47 Posts
Discussion Starter #6
Cheers guys, looks like Chris's car has a much wider powerband which is what i'm trying to achieve. And I think califcarm may have hit it on the nail, i'll give that a try and see what happens. Thanks.
 

·
Registered
Joined
·
618 Posts
No prob. Good to see different approaches and configs tried out. How did you degree the cams on the current setup?

No matter what, share the results back. Always very interesting to see how changes make a difference in the real world. :)
 

·
Registered
Joined
·
47 Posts
Discussion Starter #8 (Edited)
No prob. Good to see different approaches and configs tried out. How did you degree the cams on the current setup?

No matter what, share the results back. Always very interesting to see how changes make a difference in the real world. :)
They were degreed on the stand, but I have a feeling they are wrong as the exhaust cam isn't retarded as far as the usual deg people end up with.
 

·
Registered
Joined
·
618 Posts
Here is my revised dyno with the 264's. This time on a dynojet. I think your numbers are still in the right ballpark though. If you can find a dynojet that might give you a better idea to compare. Not always possible, I know, which is why I hadn't been on one until just recently.

Running ~18-19psi now, previously at 20psi above.

 
1 - 10 of 10 Posts
Top