This is a good read

https://www.6speedonline.com/forums/...o-results.html

I made 709 rwhp on 28s

What 28's? On what dyno?

awd or rwd? c16?

Can Alpha CHRAs be put into 1st gen GT28s (K24 based I think) from GT640 kit?

yeah but Jags you have a crap load of supporting mods as well...how much would you have made on k24/18s ...with the same supporting mods?

I'm just trying to see coming from an X50 car if I choose to mod more significantly than a the standard silicone hoses, airbox, larger IC, Dvs and an exhaust and tune ... is the power difference in TiAL A28s and k24/18 worth the cost delta between the two options?

If cost is the major consideration, then it's a no brainer. K24/18gs are the hands down bang-for-the-buck winner. They give you 85-95% of power and top end pull of the A28s with only a mild lag penalty. The cost differential is like 2X so you really need to be comfortable in the diminishing return zone to go with the A28s. I went with the A28s because I already had an EVOMS kit and these were recommended to me by Stephen Kaspar. I have really been pleased with the A28s and I am glad I bit the bullet and went with them.

Great anwswer thanks MBailey:) ...by the way very nice ride, love the wheels and 60 - 130 times!

Thank you Sunir!

Good luck with your mods!

It seems the A28's are really something special...it's may understanding that they spool quicker than the A30's and still produce similar top end power to the A3071, at least the non-billet 3071 (Which I'm very anxious to try on my car btw..).

The A28s seem to be the greatest choice for a street/track Turbo. However, there is not much real world acceleration data apart from MBailey and his crazy fast time. That is not a problem, but as you can see, the A28 vs. K24/18g dyno thread went somewhat into an argument, as not much acceleration data with different mods exists for the A28s. Of course, they are superior to 18gs as seen from the dynos...and prices. It just seems the A28 guys are just happy enjoying their cars and not posting any times. :) And MBailey has the proof of a fast one. (The Switzer P800 kits are with modified A28s, so they cannot be directly compared.)

However, at the same time it seem some K24/18g guys push easily 6.5sec 60-130mph times on PUMP GAS with 4WD with only injectors and exhaust. (I am talking about ttboost, and Greek guys). That's great performance. Can A28s with only basic mods perform similarly? I think so, but have yet no proof of it. So, that is a great statement for K24/18gs and for their bang for the buck...they do work. Of course, A28s are the modern choice with no lag (and more headroom if one gets hungry?).

I agree. However, TTboost's car has Meth injection, so he's nearly pushing race gas numbers..

I'm sure 90% the "basic" 18g cars have a hard time going under 7 sec on pump gas.


And BTW, if I think about MBailey's time being done with NO shifts....I really get goose bumps lol..

there is now k24/18gXT billet versions that should pretty much match up the A28's and be cheaper.

Did a little research... The drivers can of course correct me on this topic if needed but best 60-130s on straight pump (no meth or race fuel) I could find was 6.62 (ttboost) and 6.86 (skandalis). There very little A28 data period. Alphadog28 (Clay) ran a 6.47s but this was on meth. There is some anecdotal story about a Switzer P800 running a 6.3x on pump but this has not been verified. I have not run my car on pump in years so I have no data on what it would do. I would certainly hope it could get a 6.5x...

My numbers were on a 3.8l 1.8bar with ms109.