I have just about all the parts on the car I want and plan on scheduling a dyno session at XS within a week or two. This is a stock port motor with an HKS TO4E turbo kit.. here is the info I have on the turbo it comes with:



.84 A/R divided exhaust, I am pretty sure it is a P-trim?

.6 inlet, 57trim compressor wheel



I have been considering swapping the .84 for a 1.0 but I am not sure it will be worth the effort on a stock port motor and only a 57 trim compressor. It would be easy to upgrade the hot side since it is relatively easy to take off and I can do it myself. I am not planning on doing a full overhaul/upgrade to this turbo since it is new.. but a simple housing trade is no biggie. Maybe when I do a streetport I will stuff a 60-1 in there. Comments or suggestions?



Matt

i would dyno it first and see how it does...... it should spool REALLY fast with that .84 housing https://www.nopistons.com/forums/pub...IR#>/smile.png

yeah dyno it first, and mention a bigger housing to xs and see what they say. or i dunno, how do you like it now?



mike

Just wait and see, you may want something bigger. A 1.0 is going to pack more punch on top end, and the lag won't be that bad.

I think I will just dyno it first and see how it does, I have put so much work in modifying the car that I just want to get it on a dyno now and see some results. Vosko is right though, the turbo spools real fast.. and I have a really rich map in the PFC with very conservative timing right now. As soon as XS cleans that up I am sure it will spool even faster. I'll probably stick with the setup for now and get used to the extra power, when new motor times comes around I'll think about bumping it up again. https://www.nopistons.com/forums/pub...IR#>/smile.png



Matt

it should be very fun. especially after its tuned https://www.nopistons.com/forums/pub...IR#>/bigok.gif

I have a TO4 with a .60 cover, and a .81 ptrim, there is no lag, boost is instant, as if you are driving a V8. Carl

So, the larger the trim.. the less amount of lag?

larger=more lag

the larger the exhaust wheel or the exhaust housing will cause more lag and more top end power. A/R 1.00 divided is about the same as an A/R .84 undivided. Do you have divided or undivided?

You probably won't need any bigger than a .84 on the to4e, now if you had a 60-1, to4s, to4r, 62-1 etc you'd want the a/r 1.0 housing because those turbo's will make more top end power and you have to get the exaust out faster.. The .84 is a good match for the turbo you have, especially if your running a stock or mild side port...

I would be more worried about the DP and turbo not having fitment issues inside the engine bay when you switch to a 1.0

changing from a a/r .84 to a 1.0 won't affect the fitment of the down pipe... It will fit exactly the same.. you just need to make sure you get a 1.0 housing that has the same type of flange that your current turbo has..

Exactly, and HKS uses brackets off of the turbine housing to hold the DP in place with two bolts, it is sealed with two metal rings on the end of the DP. I haven't checked into what Garrett offers in their housings, hopefully everything isn't V-band.

that's the slip joint type, there is also a V-band and 4 bolt flange type as well...

the t04e kit i saw was 4 bolt dp



mike

I would go with a larger housing.



I think the 57 trim TO4E is highly under rated. From compressor maps it looks like it is a damn good turbo for a stock/extend ported 13B running 15psi like your average Joe does. In fact it looks better than a 60 trim TO4E, 60-1 or 62-1. I can't see any reason why it shouldn't make at least as much power as any of those turbos.



From most examples I have seen this does not appear to be the case. However all of the 57 trim cars I have seen were running small exhaust housings. I believe that the power differences seen between the turbos have more to do with the exhaust housing.



It all depend how much lag your prepared to trade for power, but I think 1.0 (divided), 0.96 (undivided), or 1.15 (divided) would all show worthwhile gains.



By the way I don't have a 57 trim TO4E, I have a 60-1 with P Trim and 0.96. However I'm considering buying the 57 compressor wheel, housing and backplate to give it a try. Its only $300 which is pretty chaep as far as turbo stuff goes.