Need help with the complete setup turbo/intercooler/injectors/MAF


@Nick Micale
Great info: you installed many RJC "air temp / same HP level with lower boost / spooling was better" compared with Precision SLIC.
The "bigger volume needs longer to build pressure" was, what my physics teacher told me :geek: Possibly it is only 1/10sec... no experience.
Therfore it is perfect, to get your input!

Just for the money, ball bearing. Read and see youtube, clearly better spool with bb!
More important for small engines, what about the GN?
Not really to feel on the street?

Let's compare Precision 5858 bb and jb please. Both i may get for a nice price here.

I like that car for every day driving with more power. Never race.
The "fast spool" quick boost when start on the traffic light, or while driving and see the "german" cars in the back mirror.
The engine should be stable, firm.
It has low mileage, but 30 years... i know, dangerous anyway.

Don't know sec, never raced 1/4ml! 400 or 450 HP... ?

I cannot play in the league with the other ones i met at Bowling Green, but i'am a little "on" now.

Good, the information of the convertor importance. (Good brand, choice of stall, lockup or not, that is all...) i thought :rolleyes:

@hensleyt @Mr.Spool

the SD2 Chip i have the ability to change and tune more variations.
Whideband all time, no MAF.
I understand it that way: the SD2 Chip is configured like 5.7 or 6.1 for your setup. Read whideband and tune, like you do by translator.
But freedom to tune ignition if necsessary, or do more other adjustments.
Is that not correct?

If need a new chip, it takes 3-4 weeks to get (for twice the price)

Thank you for your help!


Nick Micale

Tech Advisor
Staff member
Let me add some comments about turbos and converters.

First, the turbo and converter must be matched properly for the intended use of the car.

A turbo with a small exhaust housing like the stock Garrett one will provide the best response and spooling on the street. I have done many TA-49, TE-44 and TE-45A turbos for street driven performance GN's, and they have excellent response and power from a stop light compared to a Precision exhaust housing. They still need a matching converter.

A local owner with a stock car installed a TE-62 BB turbo with a billet wheel, and it leaves like a slug with the stock converter,

A proper converter should have high enough stall to spool the turbo, and also enough "slippage" to allow the tires to grip the pavement while the engine is building power.

To optimize a build for the desired performance may take one or more re-stalls, or a different converter to accomplish the goal.

This past year alone we have built 6 GN's with 500 HP for street performance, so this has given us an excellent pattern build to follow in order to satisfy the owners!

There were a few other performance GN's and the major change necessary was only the converter for them to perform as expected.


Well-Known Member
Let's compare Precision 5858 bb and jb please.
a bb turbo will spool faster than a jb turbo no matter what the design speaks for itself however,when you are dealing with enough exhaust gas volume to make the turbo come alive you have a good combo regardless if its jb or bb.on the buicks with a 3 bolt a small turbo like a 5858 with a mild converter can produce a lively combo that does not need a bb to be super responsive.